bims-rimeca Biomed News
on RNA methylation in cancer
Issue of 2023–07–09
fifty-two papers selected by
Sk Ramiz Islam, Saha Institute of Nuclear Physics
  1. METTL3 Affects Spinal Cord Neuronal Apoptosis by Regulating Bcl-2 m6A Modifications After Spinal Cord Injury.
  2. Modulation of miR-146b by N6-methyladenosine modification remodels tumor-associated macrophages and enhances anti-PD-1 therapy in colorectal cancer.
  3. Methyltransferase like 3 inhibition limits intrahepatic cholangiocarcinoma metabolic reprogramming and potentiates the efficacy of chemotherapy.
  4. METTL14 and FTO mediated m6A modification regulate PCV2 replication by affecting miR-30a-5p maturity.
  5. Expression of m6A RNA Methylation Regulators and Their Clinical Predictive Value in Intrahepatic Cholangiocarcinoma.
  6. Suppression of TLR4 prevents diabetic bone loss by regulating FTO-mediated m6A modification.
  7. m6A-mediated upregulation of miRNA-193a aggravates cardiomyocyte apoptosis and inflammatory response in sepsis-induced cardiomyopathy via the METTL3/ miRNA-193a/BCL2L2 pathway.
  8. m6A RNA modification regulates innate lymphoid cell responses in a lineage-specific manner.
  9. Altered m6A modification is involved YAP-mediated apoptosis response in 4-vinylcyclohexene diepoxide induced ovotoxicity.
  10. Epigenetic regulatory mechanism of ADAMTS12 expression in osteoarthritis.
  11. N6 -methyladenosine-modified FAM111A-DT promotes hepatocellular carcinoma growth via epigenetically activating FAM111A.
  12. NSUN2 stimulates tumor progression via enhancing TIAM2 mRNA stability in pancreatic cancer.
  13. The Role of PRRC2B in Cerebral Vascular Remodeling Under Acute Hypoxia in Mice.
  14. New insights on the interplays between m6A modifications and microRNA or lncRNA in gastrointestinal cancers.
  15. Transcriptome-wide m6A methylation in natural yellow leaf of Catalpa fargesii.
  16. Crosstalk between gut microbiota and RNA N6-methyladenosine modification in cancer.
  17. The role of m6A demethylase FTO in chemotherapy resistance mediating acute myeloid leukemia relapse.
  18. Single-Base Resolution Detection of N6-Methyladenosine in RNA by Adenosine Deamination Sequencing.
  19. UVB promotes melanogenesis by regulating METTL3.
  20. ZNF765 is a prognostic biomarker of hepatocellular carcinoma associated with cell cycle, immune infiltration, m6A modification, and drug susceptibility.
  21. RNA m5C methylation orchestrates BLCA progression via macrophage reprogramming.
  22. NOP2-mediated m5C Modification of c-Myc in an EIF3A-Dependent Manner to Reprogram Glucose Metabolism and Promote Hepatocellular Carcinoma Progression.
  23. Rna M6 a Methylation Regulates Glycolysis of Beige Fat and Contributes to Systemic Metabolic Homeostasis.
  24. LINC00426, a novel m6A-regulated long non-coding RNA, induces EMT in cervical cancer by binding to ZEB1.
  25. Rational Design of RNA Demethylase FTO Inhibitors with Enhanced Antileukemia Drug-Like Properties.
  26. Multi-Omics Analysis Reveals Translational Landscapes and Regulations in Mouse and Human Oocyte Aging.
  27. FTO-dependent m6A regulates muscle fiber remodeling in an NFATC1-YTHDF2 dependent manner.
  28. Prognostic significance of N6-methyladenosine-modified related chemotransferase METTL3 in gastric carcinoma: Evidence from meta-analysis.
  29. The prognostic value and immune landscaps of m6A/m5C-related lncRNAs signature in the low grade glioma.
  30. Identification of Novel Prognostic Biomarkers That are Associated with Immune Microenvironment Based on GABA-Related Molecular Subtypes in Gastric Cancer.
  31. Serine protease PRSS56, a novel cancer-testis antigen activated by DNA hypomethylation, promotes colorectal and gastric cancer progression via PI3K/AKT axis.
  32. m6A-related lncRNAs predict prognosis and indicate cell cycle in gastric cancer.
  33. Enhancement of TKI sensitivity in lung adenocarcinoma through m6A-dependent translational repression of Wnt signaling by circ-FBXW7.
  34. FABP5 suppresses colorectal cancer progression via mTOR-mediated autophagy by decreasing FASN expression.
  35. UHRF1 is a mediator of KRAS driven oncogenesis in lung adenocarcinoma.
  36. Clinical significance, tumor immune landscape and immunotherapy responses of ADAR in pan-cancer and its association with proliferation and metastasis of bladder cancer.
  37. Identification and prediction of m7G-related Alzheimer's disease subtypes: insights from immune infiltration and machine learning models.
  38. METTL5 serves as a diagnostic and prognostic biomarker in hepatocellular carcinoma by influencing the immune microenvironment.
  39. The role of the mitochondrial ribosomal protein family in detecting hepatocellular carcinoma and predicting prognosis, immune features, and drug sensitivity.
  40. Endoglin and squamous cell carcinomas.
  41. PPARγ agonist inhibits c-Myc-mediated colorectal cancer tumor immune escape.
  42. Modeling and therapeutic targeting of inflammation-induced hepatic insulin resistance using human iPSC-derived hepatocytes and macrophages.
  43. A negative feedback loop between KLF9 and the EMT program dictates metastasis of hepatocellular carcinoma.
  44. CircRNA SCAR Improves High-Glucose-Induced Mitochondrial Dysfunction and Permeability Damage in Retinal Microvascular Endothelial Cells.
  45. Runx2 activates hepatic stellate cells to promote liver fibrosis via transcriptionally regulating Itgav expression.
  46. Involvement of IGF1 in endoplasmic reticulum stress contributes to cataract formation through regulating Nrf2/NF-κB signaling.
  47. Regulation of glucose and glutamine metabolism to overcome cisplatin resistance in intrahepatic cholangiocarcinoma.
  48. PTEN is both an activator and a substrate of chaperone-mediated autophagy.
  49. Mitochondrial general control of amino acid synthesis 5 like 1 promotes nonalcoholic steatohepatitis development through ferroptosis-induced formation of neutrophil extracellular traps.
  50. Diacylglycerol lipase alpha promotes hepatocellular carcinoma progression and induces lenvatinib resistance by enhancing YAP activity.
  51. Estradiol cypionate inhibits proliferation and promotes apoptosis of gastric cancer by regulating AKT ubiquitination.
  52. A zebrafish xenotransplant model of anaplastic thyroid cancer to study the tumor microenvironment and innate immune cell interactions in vivo.
  1. Neurospine. 2023 Jun;20(2): 623-636
    METTL3 Affects Spinal Cord Neuronal Apoptosis by Regulating Bcl-2 m6A Modifications After Spinal Cord Injury.
    Shengyu Guo, Taotao Lin, Gang Chen, Zhitao Shangguan, Linquan Zhou, Zhi Chen, Tengbin Shi, Dehui Chen, Zhenyu Wang, Wenge Liu.
       OBJECTIVE: Spinal cord injury (SCI) is a severe type of neurological trauma. N6-methyladenosine (m6A) modification is one of the most common internal modifications of RNA. The role of METTL3, the predominant methylation enzyme of m6A modification, in SCI remains unclear. This study aimed to investigate the role of methyltransferase METTL3 in SCI.
    METHODS: After establishing the oxygen-glucose deprivation (OGD) model of PC12 cells and rat spinal cord hemisection model, we found that the expression of METTL3 and the overall m6A modification level were significantly increased in neurons. The m6A modification was identified on B-cell lymphoma 2 (Bcl-2) messenger RNA (mRNA) by bioinformatics analysis, and m6A-RNA immunoprecipitation and RNA immunoprecipitation. In addition, METTL3 was blocked by the specific inhibitor STM2457 and gene knockdown, and then apoptosis levels were measured.
    RESULTS: In different models, we found that the expression of METTL3 and the overall m6A modification level were significantly increased in neurons. After inducing OGD, inhibition of METTL3 activity or expression increased the mRNA and protein levels of Bcl-2, inhibited neuronal apoptosis, and improved neuronal viability in the spinal cord.
    CONCLUSION: Inhibition of METTL3 activity or expression can inhibit the apoptosis of spinal cord neurons after SCI through the m6A/Bcl-2 signaling pathway.
    Keywords:  Bcl-2; METTL3; Oxygen-glucose deprivation; STM2457; Spinal cord injury; m6A
    DOI:  https://doi.org/10.14245/ns.2346170.085
  2. Cell Oncol (Dordr). 2023 Jul 05.
    Modulation of miR-146b by N6-methyladenosine modification remodels tumor-associated macrophages and enhances anti-PD-1 therapy in colorectal cancer.
    Shuying He, Wen Song, Shudan Cui, Jiating Li, Yonghong Jiang, Xueqing Chen, Liang Peng.
       PURPOSE: MicroRNA-146b (miR-146b) alleviates experimental colitis in mice by mediating macrophage polarization and the release of inflammatory factors. Our goals were to evaluate the antitumor efficacy of miR-146b in colorectal cancer (CRC) and to investigate the underlying mechanisms.
    METHODS: We used murine models of CRC to evaluate whether miR-146b influenced the progression of tumors independent of tumor-associated macrophages (TAMs). RNA immunoprecipitation, N6-methyladenosine (m6A) RNA immunoprecipitation and in vitro pri-miRNA processing assays were conducted to examine whether m6A mediates the maturation of pri-miR-146b/miR-146b. In a series of in vitro and in vivo experiments, we further defined the molecular mechanisms of methyltransferase-like 3 (METTL3)/miR-146b-mediated antitumor immunity and its efficacy in combination with anti-PD-1 immunotherapy.
    RESULTS: We found that miR-146b deletion supported tumor progression by increasing the number of alternatively activated (M2) TAMs. Mechanistically, the m6A-related "writer" protein METTL3 and "reader" protein HNRNPA2B1 controlled miR-146b maturation by regulating the m6A modification region of pri-miR-146b. Furthermore, miR-146b deletion promoted the polarization of M2-TAMs by enhancing phosphoinositide 3-kinase (PI3K)/AKT signaling, and this effect was mediated by the class IA PI3K catalytic subunit p110β, which reduced T cell infiltration, aggravated immunosuppression and ultimately promoted tumor progression. METTL3 knockdown or miR-146b deletion induced programmed death ligand 1 (PD-L1) production via the p110β/PI3K/AKT pathway in TAMs and consequently augmented the antitumor activity of anti-PD-1 immunotherapy.
    CONCLUSIONS: The maturation of pri-miR-146b is m6A-dependent, and miR-146b deletion-mediated TAM differentiation promotes the development of CRC by activating the PI3K/AKT pathway, which induces upregulation of PD-L1 expression, inhibits T cell infiltration into the TME and enhances the antitumor activity of anti-PD-1 immunotherapy. The findings reveal that targeting miR-146b can serve as an adjuvant to anti-PD-1 immunotherapy.
    Keywords:  Colorectal cancer; N6-methyladenosine; PD-1; PD-L1; Tumor-associated macrophages; miR-146b
    DOI:  https://doi.org/10.1007/s13402-023-00839-0
  3. Oncogene. 2023 Jul 07.
    Methyltransferase like 3 inhibition limits intrahepatic cholangiocarcinoma metabolic reprogramming and potentiates the efficacy of chemotherapy.
    Jun Gao, Yuan Fang, Jiafeng Chen, Zheng Tang, Mengxin Tian, Xifei Jiang, Chenyang Tao, Run Huang, Guiqi Zhu, Weifeng Qu, Xiaoling Wu, Jian Zhou, Jia Fan, Weiren Liu, Yinghong Shi.
      N6-methyladenosine (m6A) RNA methylation and its associated methyltransferase like 3 (METTL3) are involved in the development and maintenance of various tumors. The present study aimed to evaluate the cross-talk of METTL3 with glucose metabolism and reveal a novel mechanism for intrahepatic cholangiocarcinoma (ICC) progression. Real-time quantitative PCR, western blotting, and immunohistochemistry analyses suggested that METTL3 was highly expressed in ICC, which was correlated with poor patient prognosis. Immunoprecipitation sequencing of m6A-RNA showed that METTL3 upregulated m6A modification of NFAT5, which recruited IGF2BP1 for NFAT5 mRNA stabilization. Elevated expression of NFAT5 increased the expression of the gluconeogenesis-related genes GLUT1 and PGK1, resulting in enhanced aerobic glycolysis, proliferation, and tumor metastasis of ICC. Moreover, higher METTL3 expression was observed in tumor tissues of ICC patients with activated ICC glucose metabolism. Importantly, STM2457, a highly potent METTL3 inhibitor, which inhibited METTL3 activity and acted synergistically with gemcitabine, suggests that reprogramming RNA epigenetic modifications may serve as a potential therapeutic strategy. Overall, our findings highlighted the role of METTL3-mediated m6A modification of NFAT5 in activating glycolytic reprogramming in ICC and proposed that the METTL3/NFAT5 axis was a clinical target for the management of ICC chemoresistance by targeting cancer glycolysis.
    DOI:  https://doi.org/10.1038/s41388-023-02760-0
  4. Virulence. 2023 Dec;14(1): 2232910
    METTL14 and FTO mediated m6A modification regulate PCV2 replication by affecting miR-30a-5p maturity.
    Chen Li, Xiaoyan Wu, Ying Yang, Jianli Shi, Shuo Wang, Jiaxin Li, Yao Tian, Chang Liu, Hong Han, Shaojian Xu, Xianjie Han, Yingru Ma, Limei Zheng, Jun Li.
      The epigenetic modification of the N6-methyladenosine (m6A) methylation plays an important role in virus infection and replication. However, its role in Porcine circovirus type 2 (PCV2) replication has not been well studied. Here, we demonstrated that m6A modifications are increased in PK-15 cells after PCV2 infection. In particular, PCV2 infection could increase the expression of methyltransferase METTL14 and demethylase FTO. Moreover, interfering with METTL14 accumulation reduced the m6A methylation level and virus reproduction, whereas depleting the FTO demethylase enhanced the m6A methylation level and stimulated virus reproduction. Besides, we showed that METTL14 and FTO regulate PCV2 replication by affecting the process of miRNA maturity, especially the miRNA-30a-5p. Taken together, our results demonstrated that the m6A modification positively affects PCV2 replication and the role of m6A modification in the replication mechanism of the PCV2 virus provides a new idea for the prevention and control of the PCV2.
    Keywords:  Porcine circovirus type 2; m6A modification; miRNA maturity; replication
    DOI:  https://doi.org/10.1080/21505594.2023.2232910
  5. Front Biosci (Landmark Ed). 2023 06 27. 28(6): 120
    Expression of m6A RNA Methylation Regulators and Their Clinical Predictive Value in Intrahepatic Cholangiocarcinoma.
    Feng Wei, Jia-Ning Zhang, Yu-Qing Zhao, Hongwei Lyu, Fengyuan Chen.
       BACKGROUND: N6-methyladenosine (m6A) RNA methylation regulators have been implicated in the carcinogenesis and progress of a variety of cancers. Until now, the effects of them on intrahepatic cholangiocarcinoma (ICC) have been poorly understood.
    METHODS: We used the GEO databases to systematically evaluate the expression profiles of 36 m6A RNA methylation regulators in ICC patients and produced a signature to assess its prognostic values. In vitro experiments were implemented to confirm the expression level.
    RESULTS: Compared to normal intrahepatic bile duct tissues, more than half of these 36 genes showed different levels of expression in ICC tissues. Two groups emerged from the consensus cluster analysis of these 36 genes. The two cluster of patients had significantly different clinical outcomes. In addition, we created a m6A-related prognostic signature that performed exceptionally well in the prognostic categorization of ICC patients, based on the ROC curves, Kaplan-Meier curves, and univariate and multivariate Cox regression analyses. Further research showed that there was a significant association between the m6A-related signature and the manifestations of tumor immune microenvironment in ICC. The expression level and biological effect of METTL16, one of the two m6A RNA methylation regulators incorporated in the signature, were confirmed and explored by using in vitro experiments.
    CONCLUSIONS: This analysis revealed the predictive roles of m6A RNA methylation regulators in ICC.
    Keywords:  GEO database; intrahepatic cholangiocarcinoma; m6A RNA methylation regulators; prognosis; signature
    DOI:  https://doi.org/10.31083/j.fbl2806120
  6. Int Immunopharmacol. 2023 Jul 04. pii: S1567-5769(23)00833-0. [Epub ahead of print]122 110510
    Suppression of TLR4 prevents diabetic bone loss by regulating FTO-mediated m6A modification.
    Ximei Shen, Chao Lan, Youfen Lin, Fuyashi Zhang, Yongze Zhang, Mingyun Chen, Sunjie Yan.
      Toll-like receptor-4 (TLR4) has been implicated in the development and progression of diabetic osteoporosis. However, the mechanisms underlying TLR4-regulated bone metabolism in diabetes are yet to be fully understood. Epigenetic modifications have been indicated as a possible mechanism leading to increased risk of osteoporosis and bone fracture. As N6-methyladenosine (m6A) is the most common epigenetic modification in eukaryotic mRNAs, we hypothesized that TLR4 regulates m6A modification in bone tissues of diabetic rats, thereby potentially explaining the pathogenesis of diabetic bone loss. m6A sequencing (m6A-seq) was performed in samples of the femur of TLR4-wild type (TLR4WT) and TLR4-knockout (TLR4KO) diabetic rats to identify genes with differential m6A modifications that may be associated with the bone loss phenotype. We found that in TLR4KO rats, the rapid weight loss of diabetic rats was prevented, and bone mineral density (BMD) was significantly increased. m6A-seq and Gene Ontology enrichment analysis revealed that m6A-modified genes in the femur of TLR4KO diabetic rats were associated with regulation of biological processes such as osteoclast differentiation. qRT-PCR analysis on the expression levels of the m6A-modified methyltransferases and demethylases demonstrated that only the m6A demethylase fat mass and obesity-associated protein（FTO）was decreased. Using an osteoclast cell model, we confirmed that TLR4-mediated osteoclast differentiation was induced by glycolipid toxicity via inhibition of FTO expression. Taken together, these results suggest that inhibition of TLR4 may prevent diabetic bone loss via regulation of FTO-mediated m6A modification.
    Keywords:  Bone metabolism; Diabetes; FTO; TLR4; m6A
    DOI:  https://doi.org/10.1016/j.intimp.2023.110510
  7. Exp Cell Res. 2023 Jul 04. pii: S0014-4827(23)00260-4. [Epub ahead of print] 113712
    m6A-mediated upregulation of miRNA-193a aggravates cardiomyocyte apoptosis and inflammatory response in sepsis-induced cardiomyopathy via the METTL3/ miRNA-193a/BCL2L2 pathway.
    Lian Liang, Siqi Liu, Qingyu Wu, Ran Chen, Shanping Jiang, Zhengfei Yang.
      The impact of N6-methyladenosine (m6A) modification on pri-miRNA in sepsis-induced cardiomyopathy (SICM), and its underlying regulatory mechanism, have not been fully elucidated. We successfully constructed a SICM mice model through cecal ligation and puncture (CLP). In vitro, a lipopolysaccharide (LPS)-induced HL-1 cells model was also established. The results showed that sepsis frequently resulted in excessive inflammatory response concomitant with impaired myocardial function in mice exposed to CLP, as indicated by decreases in ejection fraction (EF), fraction shortening (FS), and left ventricular end diastolic diameters (LVDd). miR-193a was enriched in CLP mice heart and in LPS-treated HL-1 cells, while overexpression of miR-193a significantly increased the expression levels of cytokines. Sepsis-induced enrichment of miR-193a significantly inhibited cardiomyocytes proliferation and enhanced apoptosis, while this was reversed by miR-193a knockdown. Furthermore, under our experimental conditions, enrichment of miR-193a in SICM could be considered excessively maturated on pri-miR-193a by enhanced m6A modification. This modification was catalyzed by sepsis-induced overexpression of methyltransferase-like 3 (METTL3). Moreover, mature miRNA-193a bound to a predictive sequence within 3'UTRs of a downstream target, BCL2L2, which was further validated by the observation that the BCL2L2-3'UTR mutant failed to decrease luciferase activity when co-transfected with miRNA-193a. The interaction between miRNA-193a and BCL2L2 resulted in BCL2L2 downregulation, subsequently activating the caspase-3 apoptotic pathway. In conclusion, sepsis-induced miR-193a enrichment via m6A modification plays an essential regulatory role in cardiomyocyte apoptosis and inflammatory response in SICM. The detrimental axis of METTL3/m6A/miR-193a/BCL2L2 is implicated in the development of SICM.
    Keywords:  Apoptosis; BCL2L2; Sepsis-induced cardiomyopathy; m6A; miRNA-193a
    DOI:  https://doi.org/10.1016/j.yexcr.2023.113712
  8. Nat Immunol. 2023 Jul 03.
    m6A RNA modification regulates innate lymphoid cell responses in a lineage-specific manner.
    Yingyu Zhang, Wanwei Zhang, Jingyao Zhao, Takamasa Ito, Jiacheng Jin, Alexis O Aparicio, Junsong Zhou, Vincent Guichard, Yinshan Fang, Jianwen Que, Joseph F Urban, Jacob H Hanna, Sankar Ghosh, Xuebing Wu, Lei Ding, Uttiya Basu, Yuefeng Huang.
      Innate lymphoid cells (ILCs) can quickly switch from a quiescent state to an active state and rapidly produce effector molecules that provide critical early immune protection. How the post-transcriptional machinery processes different stimuli and initiates robust gene expression in ILCs is poorly understood. Here, we show that deletion of the N6-methyladenosine (m6A) writer protein METTL3 has little impact on ILC homeostasis or cytokine-induced ILC1 or ILC3 responses but significantly diminishes ILC2 proliferation, migration and effector cytokine production and results in impaired antihelminth immunity. m6A RNA modification supports an increase in cell size and transcriptional activity in activated ILC2s but not in ILC1s or ILC3s. Among other transcripts, the gene encoding the transcription factor GATA3 is highly m6A methylated in ILC2s. Targeted m6A demethylation destabilizes nascent Gata3 mRNA and abolishes the upregulation of GATA3 and ILC2 activation. Our study suggests a lineage-specific requirement of m6A for ILC2 responses.
    DOI:  https://doi.org/10.1038/s41590-023-01548-4
  9. Ecotoxicol Environ Saf. 2023 Jun 30. pii: S0147-6513(23)00696-6. [Epub ahead of print]262 115192
    Altered m6A modification is involved YAP-mediated apoptosis response in 4-vinylcyclohexene diepoxide induced ovotoxicity.
    Yang Li, Meifang Li, Jian Liu, Guangning Nie, Hongyan Yang.
      4-Vinylcyclohexene diepoxide (VCD), an industrial occupational health hazard chemical associated with premature ovarian insufficiency (POI) and reproductive failure. Recently, investigators have paid an increasing attention on VCD model of menopause recapitulates the natural, physiological transition through perimenopause to menopause. The current study sought to examining the mechanisms of follicular loss and exploring the effect of the model on systems outside of the ovaries. In this study, 28 days female SD rats were injected with VCD (160 mg/kg) vehicle for 15 consecutive days, euthanized in the diestrus phase approximately 100 days after the onset of treatment. Reproductive system injury, Neuroendocrine, sex hormone levels and receptor were observed, the levels of N6-methyladenosine (m6A) RNA modification and the expression of modulator genes were first measured. The VCD treated rats showing irregular estrous cycles, significantly reduced in the number of primordial follicles, the preantral and antral follicles also decreased significantly, accompanied by the plasma level of FSH increased and anti-Mullerian hormone (AMH) were decreased. The total m6A level was significantly decreased after exposure to VCD. Moreover, ALKBH5-mediated YAP m6A modification changed in VCD - induced premature ovarian insufficiency. These present work provides a new perspective on m6A modification in the VCD-induced POI rat model, which could provide valuable insights into the mechanisms underlying follicle development and finding new therapeutic targets for follicle prematurely exhausted. Also provide novel methodological guidance and endocrine basis to guide research and extend the applications in premature ovarian insufficiency model.
    Keywords:  ALKBH5; Environmental exposure; N6-methyladenosine; Premature ovarian insufficiency Model; VCD; YAP
    DOI:  https://doi.org/10.1016/j.ecoenv.2023.115192
  10. Mol Med. 2023 07 03. 29(1): 86
    Epigenetic regulatory mechanism of ADAMTS12 expression in osteoarthritis.
    Shu Yang, Xuanping Zhou, Zhen Jia, Mali Zhang, Minghao Yuan, Yizhao Zhou, Jing Wang, Duo Xia.
       BACKGROUND: Osteoarthritis (OA) is a degenerative joint disease with lacking effective prevention targets. A disintegrin and metalloproteinase with thrombospondin motifs 12 (ADAMTS12) is a member of the ADAMTS family and is upregulated in OA pathologic tissues with no fully understood molecular mechanisms.
    METHODS: The anterior cruciate ligament transection (ACL-T) method was used to establish rat OA models, and interleukin-1 beta (IL-1β) was administered to induce rat chondrocyte inflammation. Cartilage damage was analyzed via hematoxylin-eosin, Periodic Acid-Schiff, safranin O-fast green, Osteoarthritis Research Society International score, and micro-computed tomography assays. Chondrocyte apoptosis was detected by flow cytometry and TdT dUTP nick-end labeling. Signal transducer and activator of transcription 1 (STAT1), ADAMTS12, and methyltransferase-like 3 (METTL3) levels were detected by immunohistochemistry, quantitative polymerase chain reaction (qPCR), western blot, or immunofluorescence assay. The binding ability was confirmed by chromatin immunoprecipitation-qPCR, electromobility shift assay, dual-luciferase reporter, or RNA immunoprecipitation (RIP) assay. The methylation level of STAT1 was analyzed by MeRIP-qPCR assay. STAT1 stability was investigated by actinomycin D assay.
    RESULTS: The STAT1 and ADAMTS12 expressions were significantly increased in the human and rat samples of cartilage injury, as well as in IL-1β-treated rat chondrocytes. STAT1 is bound to the promoter region of ADAMTS12 to activate its transcription. METTL3/ Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) mediated N6-methyladenosine modification of STAT1 promoted STAT1 mRNA stability, resulting in increased expression. ADAMTS12 expression was reduced and the IL-1β-induced inflammatory chondrocyte injury was attenuated by silencing METTL3. Additionally, knocking down METTL3 in ACL-T-produced OA rats reduced ADAMTS12 expression in their cartilage tissues, thereby alleviating cartilage damage.
    CONCLUSION: METTL3/IGF2BP2 axis increases STAT1 stability and expression to promote OA progression by up-regulating ADAMTS12 expression.
    Keywords:  ADAMTS12; IGF2BP2; Inflammation; METTL3; Osteoarthritis; STAT1
    DOI:  https://doi.org/10.1186/s10020-023-00661-2
  11. Cancer Sci. 2023 Jul 03.
    N6 -methyladenosine-modified FAM111A-DT promotes hepatocellular carcinoma growth via epigenetically activating FAM111A.
    Jian Pu, Zuoming Xu, Youguan Huang, Jiahui Nian, Meng Yang, Quan Fang, Qing Wei, Zihua Huang, Guoman Liu, Jianchu Wang, Xianjian Wu, Huamei Wei.
      As an epitranscriptomic modulation manner, N6 -methyladenosine (m6 A) modification plays important roles in various diseases, including hepatocellular carcinoma (HCC). m6 A modification affects the fate of RNAs. The potential contributions of m6 A to the functions of RNA still need further investigation. In this study, we identified long noncoding RNA FAM111A-DT as an m6 A-modified RNA and confirmed three m6 A sites on FAM111A-DT. The m6 A modification level of FAM111A-DT was increased in HCC tissues and cell lines, and increased m6 A level was correlated with poor survival of HCC patients. m6 A modification increased the stability of FAM111A-DT transcript, whose expression level showed similar clinical relevance to that of the m6 A level of FAM111A-DT. Functional assays found that only m6 A-modified FAM111A-DT promoted HCC cellular proliferation, DNA replication, and HCC tumor growth. Mutation of m6 A sites on FAM111A-DT abolished the roles of FAM111A-DT. Mechanistic investigations found that m6 A-modified FAM111A-DT bound to FAM111A promoter and also interacted with m6 A reader YTHDC1, which further bound and recruited histone demethylase KDM3B to FAM111A promoter, leading to the reduction of the repressive histone mark H3K9me2 and transcriptional activation of FAM111A. The expression of FAM111A was positively correlated with the m6 A level of FAM111A-DT, and the expression of methyltransferase complex, YTHDC1, and KDM3B in HCC tissues. Depletion of FAM111A largely attenuated the roles of m6 A-modified FAM111A-DT in HCC. In summary, the m6 A-modified FAM111A-DT/YTHDC1/KDM3B/FAM111A regulatory axis promoted HCC growth and represented a candidate therapeutic target for HCC.
    Keywords:  DNA replication; N6-methyladenosine; epigenetic modulation; hepatocellular carcinoma; histone methylation
    DOI:  https://doi.org/10.1111/cas.15886
  12. Cell Death Discov. 2023 Jul 01. 9(1): 219
    NSUN2 stimulates tumor progression via enhancing TIAM2 mRNA stability in pancreatic cancer.
    Guizhen Zhang, Liwen Liu, Jianhao Li, Yu Chen, Yun Wang, Yize Zhang, Zihui Dong, Wenhua Xue, Ranran Sun, Guangying Cui.
      NSUN2 is a nuclear RNA methyltransferase which catalyzes 5-methylcytosine (m5C), a posttranscriptional RNA modification. Aberrant m5C modification has been implicated in the development of multiple malignancies. However, its function in pancreatic cancer (PC) needs to be elucidated. Herein, we determined that NSUN2 was overexpressed in PC tissues and related to aggressive clinical features. Silence of NSUN2 by lentivirus weakened the capability of proliferation, migration and invasion of PC cells in vitro and inhibited the growth and metastasis of xenograft tumors in vivo. Contrarily, overexpression of NSUN2 stimulated PC growth and metastasis. Mechanistically, m5C-sequencing (m5C-seq) and RNA-sequencing (RNA-seq) were carried out to identify downstream targets of NSUN2 and results showed that loss of NSUN2 led to decreased m5C modification level concomitant with reduced TIAM2 mRNA expression. Further validation experiments proved that NSUN2 silence accelerated the decay of TIAM2 mRNA in a YBX1-dependent manner. Additionally, NSUN2 exerted its oncogenic function partially through enhancing TIAM2 transcription. More importantly, disruption of the NSUN2/TIAM2 axis repressed the malignant phenotype of PC cells through blocking epithelial-mesenchymal transition (EMT). Collectively, our study highlighted the critical function of NSUN2 in PC and provided novel mechanistic insights into NSUN2/TIAM2 axis as promising therapeutic targets against PC.
    DOI:  https://doi.org/10.1038/s41420-023-01521-y
  13. Adv Sci (Weinh). 2023 Jul 03. e2300892
    The Role of PRRC2B in Cerebral Vascular Remodeling Under Acute Hypoxia in Mice.
    Shuoshuo Li, Wenyu Hu, Shenghui Gong, Ping Zhang, Jinbo Cheng, Shukun Wang, Yingyi Wang, Wenjun Shi, Qianqian Li, Fengchao Wang, Zengqiang Yuan.
      High altitude exposure leads to various cognitive impairments. The cerebral vasculature system plays an integral role in hypoxia-induced cognitive defects by reducing oxygen and nutrition supply to the brain. RNA N6-methyladenosine (m6A) is susceptible to modification and regulates gene expression in response to environmental changes, including hypoxia. However, the biological significance of m6A in endothelial cell performance under hypoxic conditions is unknown. Using m6A-seq, RNA immunoprcipitation-seq, and transcriptomic co-analysis, the molecular mechanism of vascular system remodeling under acute hypoxia is investigated. A novel m6A reader protein, proline-rich coiled-coil 2B (PRRC2B), exists in endothelial cells. PRRC2B knockdown promoted hypoxia-induced endothelial cell migration by regulating alternative splicing of the alpha 1 chain of collagen type XII in an m6A-dependent manner and the decay of matrix metallopeptidase domain 14 and ADAM metallopeptidase domain 19 mRNA in an m6A-independent manner. In addition, conditional knockout of PRRC2B in endothelial cells promotes hypoxia-induced vascular remodeling and cerebral blood flow redistribution, thus alleviating hypoxia-induced cognitive decline. Therefore, PRRC2B is integral in the hypoxia-induced vascular remodeling process as a novel RNA-binding protein. These findings provide a new potential therapeutic target for hypoxia-induced cognitive decline.
    Keywords:  COL12A1; N6-methyladenosine; cognitive defect; hypoxia; proline-rich coiled-coil 2B; vascular remodeling
    DOI:  https://doi.org/10.1002/advs.202300892
  14. Front Cell Dev Biol. 2023 ;11 1157797
    New insights on the interplays between m6A modifications and microRNA or lncRNA in gastrointestinal cancers.
    Tao Su, Jiandong Liu, Nasha Zhang, Teng Wang, Linyu Han, Suzhen Wang, Ming Yang.
      N6-Methyladenosine (m6A) methylation is one of the most extremely examined RNA modifications. M6A modification evidently impacts cancer development by effecting RNA metabolism. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are involved in multiple essential biological processes by regulating gene expression at the transcriptional and post-transcriptional levels. Accumulated evidences indicated that m6A is involved in regulating the cleavage, stability, structure, transcription, and transport of lncRNAs or miRNAs. Additionally, ncRNAs also play significant roles in modulating m6A levels of malignant cells by participating in the regulation of m6A methyltransferases, the m6A demethylases and the m6A binding proteins. In this review, we systematically summarize the new insight on the interactions between m6A and lncRNAs or miRNAs, as well as their impacts on gastrointestinal cancer progression. Although there are still extensive studies on genome-wide screening of crucial lncRNAs or miRNAs involved in regulating m6A levels of mRNAs and disclosing differences on mechanisms of regulating m6A modification of lncRNAs, miRNAs or mRNAs in cancer cells, we believe that targeting m6A-related lncRNAs and miRNAs may provide novel options for gastrointestinal cancer treatments.
    Keywords:  RNA modification; lncRNA; m6A modification; microRNA; ncRNA
    DOI:  https://doi.org/10.3389/fcell.2023.1157797
  15. Front Plant Sci. 2023 ;14 1167789
    Transcriptome-wide m6A methylation in natural yellow leaf of Catalpa fargesii.
    Yu Zhang, Junhui Wang, Wenjun Ma, Nan Lu, Pengyue Fu, Yingying Yang, Linjiao Zhao, Jiwen Hu, Guanzheng Qu, Nan Wang.
      N6-methyladenosine (m6A) is the most abundant internal modification in eukaryotic messenger RNA, and involved in various biological processes in plants. However, the distribution features and functions of mRNA m6A methylation have been poorly explored in woody perennial plants. In this study, a new natural variety with yellow-green leaves, named Maiyuanjinqiu, was screened from the seedlings of Catalpa fargesii. Based on the preliminary experiment, the m6A methylation levels in the leaves of Maiyuanjinqiu were significantly higher than those in C. fargesii. Furthermore, a parallel analysis of m6A-seq and RNA-seq was carried out in different leaf color sectors. The result showed that m6A modification were mostly identified around the 3'-untranslated regions (3'-UTR), which was slightly negatively correlated with the mRNA abundance. KEGG and GO analyses showed that m6A methylation genes were associated with photosynthesis, pigments biosynthesis and metabolism, oxidation-reduction and response to stress, etc. The overall increase of m6A methylation levels in yellow-green leaves might be associated with the decreased the expression of RNA demethylase gene CfALKBH5. The silencing of CfALKBH5 caused a chlorotic phenotype and increased m6A methylation level, which further confirmed our hypothesis. Our results suggested that mRNA m6A methylation could be considered as a vital epigenomic mark and contribute to the natural variations in plants.
    Keywords:  Catalpa fargesii; CfALKBH5; Epitranscriptomics; N6-methyladenosine; RNA methylation; yellow-green leaf
    DOI:  https://doi.org/10.3389/fpls.2023.1167789
  16. FEMS Microbiol Rev. 2023 Jul 05. pii: fuad036. [Epub ahead of print]
    Crosstalk between gut microbiota and RNA N6-methyladenosine modification in cancer.
    Hao Su, Henley Cheung, Harry Cheuk-Hay Lau, Hongyan Chen, Xiaoting Zhang, Na Qin, Yifei Wang, Matthew Tak Vai Chan, William Ka Kei Wu, Huarong Chen.
      The gut microbiota plays a crucial role in regulating various host metabolic, immune, and neuroendocrine functions, and has a significant impact on human health. Several lines of evidence suggest that gut dysbiosis is associated with a variety of diseases, including cancer. The gut microbiota can impact the development and progression of cancer through a range of mechanisms, such as regulating cell proliferation and death, modulating the host immune response, and altering the host metabolic state. Gene regulatory programs are considered critical mediators between the gut microbiota and host phenotype, of which RNA N6-methyladenosine (m6A) modifications have attracted much attention recently. Aberrant m6A modifications have been shown to play a crucial role in cancer development. This review aims to provide an overview of the diverse roles of gut microbiota and RNA m6A modifications in cancer and highlight their potential interactions in cancer development.
    Keywords:  Cancer; Crosstalk; Microbiota; N6-methyladenosine
    DOI:  https://doi.org/10.1093/femsre/fuad036
  17. Cell Death Discov. 2023 Jul 05. 9(1): 225
    The role of m6A demethylase FTO in chemotherapy resistance mediating acute myeloid leukemia relapse.
    Zhi-Wei Zhang, Xiao-Su Zhao, Huidong Guo, Xiao-Jun Huang.
      Acute myeloid leukemia (AML) is the most common hematopoietic malignancies, and chemotherapy resistance is one of the main causes of relapse. Because of lower survival rate for patients with relapse, it is pivotal to identify etiological factors responsible for chemo-resistance. In this work, direct MeRIP-seq analysis of sequential samples at stage of complete remission (CR) and relapse identifies that dysregulated N6-methyladenosine (m6A) methylation is involved in this progression, and hypomethylated RNAs are related to cell differentiation. m6A demethylase FTO is overexpressed in relapse samples, which enhances the drug resistance of AML cells in vivo and in vitro. In addition, FTO knockdown cells exhibit stronger capacity of differentiation towards granules and myeloid lineages after cytosine arabinoside (Ara-C) treatment. Mechanistically, FOXO3 is identified as a downstream target of FTO, the hypomethylation of FOXO3 mRNA affects its RNA degradation and further reduces its own expression, which ultimately result in attenuated cell differentiation. Collectively, these results demonstrate that FTO-m6A-FOXO3 is the main regulatory axis to affect the chemotherapy resistance of AML cells and FTO is a potential therapeutic target of chemotherapy resistance in AML.
    DOI:  https://doi.org/10.1038/s41420-023-01505-y
  18. Anal Chem. 2023 Jul 04.
    Single-Base Resolution Detection of N6-Methyladenosine in RNA by Adenosine Deamination Sequencing.
    Wen-Xuan Shao, Yi-Hao Min, Wei Chen, Jun Xiong, Xia Guo, Neng-Bin Xie, Shan Zhang, Si-Yu Yu, Conghua Xie, Yu-Qi Feng, Bi-Feng Yuan.
      N6-Methyladenosine (m6A) is one of the most abundant and prevalent natural modifications occurring in diverse RNA species. m6A plays a wide range of roles in physiological and pathological processes. Revealing the functions of m6A relies on the faithful detection of individual m6A sites in RNA. However, developing a simple method for the single-base resolution detection of m6A is still a challenging task. Herein, we report an adenosine deamination sequencing (AD-seq) technique for the facile detection of m6A in RNA at single-base resolution. The AD-seq approach capitalizes on the selective deamination of adenosine, but not m6A, by the evolved tRNA adenosine deaminase (TadA) variant of TadA8e or the dimer protein of TadA-TadA8e. In AD-seq, adenosine is deaminated by TadA8e or TadA-TadA8e to form inosine, which pairs with cytidine and is read as guanosine in sequencing. m6A resists deamination due to the interference of the methyl group at the N6 position of adenosine. Thus, the m6A base pairs with thymine and is still read as adenosine in sequencing. The differential readouts from A and m6A in sequencing can achieve the single-base resolution detection of m6A in RNA. Application of the proposed AD-seq successfully identified individual m6A sites in Escherichia coli 23S rRNA. Taken together, the proposed AD-seq allows simple and cost-effective detection of m6A at single-base resolution in RNA, which provides a valuable tool to decipher the functions of m6A in RNA.
    DOI:  https://doi.org/10.1021/acs.analchem.3c00502
  19. J Cell Physiol. 2023 Jul 07.
    UVB promotes melanogenesis by regulating METTL3.
    Haoran Guo, Hongliang Zeng, Yibo Hu, Ling Jiang, Li Lei, Jinhua Hung, Chuhan Fu, Hui Li, Yan Long, Jing Chen, Qinghai Zeng.
      Ultraviolet (UV) radiation is the primary exogenous inducer of skin pigmentation, although the mechanism has not been fully elucidated. N6-methyladenosine (m6 A) modification is one of the key epigenetic form of gene regulation that affects multiple biological processes. The aim of this study was to explore the role and underlying mechanisms of m6 A modification in UVB-induced melanogenesis. Low-dose UVB increased global m6 A modification in melanocytes (MCs) and MNT1 melanoma cell line. The GEPIA database predicted that methyltransferase METTL3 is positively correlated with the melanogenic transcription factor MITF in the sun-exposed skin tissues. After METTL3 respectively overexpressed and knocked down in the MNT1, the melanin content and melanogenesis-related genes were significantly upregulated after overexpression of METTL3, especially with UVB irradiation, and downregulated after METTL3 knockdown. METTL3 levels were also higher in melanocytic nevi with high melanin content. METTL3 overexpression and knockdown also altered the protein level of YAP1. SRAMP analysis predicted four high-potential m6 A modification sites on YAP1 mRNA, of which three were confirmed by methylated RNA immunoprecipitation. Inhibition of YAP1 expression can partially reverse melanogenesis induced by overexpression of METTL3. In conclusion, UVB irradiation promotes global m6 A modification in MCs and upregulates METTL3, which increases the expression level of YAP1 through m6 A modification, thereby activating the co-transcription factor TEAD1 and promoting melanogenesis.
    Keywords:  METTL3; N6-methyladenine; YAP; melanogenesis; ultraviolet
    DOI:  https://doi.org/10.1002/jcp.31077
  20. Aging (Albany NY). 2023 Jul 04. 15
    ZNF765 is a prognostic biomarker of hepatocellular carcinoma associated with cell cycle, immune infiltration, m6A modification, and drug susceptibility.
    Yongqi Ding, Yiyang Gong, Hong Zeng, Gelin Song, Zichuan Yu, Bidong Fu, Yue Liu, Da Huang, Yanying Zhong.
      Hepatocellular carcinoma (HCC) is an ongoing challenge worldwide. Zinc finger protein 765 (ZNF765) is an important zinc finger protein that is related to the permeability of the blood-tumor barrier. However, the role of ZNF765 in HCC is unclear. This study evaluated the expression of ZNF765 in hepatocellular carcinoma and the impact of its expression on patient prognosis based on The Cancer Genome Atlas (TCGA). Immunohistochemical assays (IHC) were used to examine protein expression. Besides, a colony formation assay was used to examine cell viability. We also explored the relationship between ZNF765 and chemokines in the HCCLM3 cells by qRT-PCR. Moreover, we examined the effect of ZNF765 on cell resistance by measurement of the maximum half-inhibitory concentration. Our research revealed that ZNF765 expression in HCC samples was higher than that in normal samples, whose upregulation was not conducive to the prognosis. The results of GO, KEGG, and GSEA showed that ZNF765 was associated with the cell cycle and immune infiltration. Furthermore, we confirmed that the expression of ZNF765 had a strong connection with the infiltration level of various immune cells, such as B cells, CD4+ T cells, macrophages, and neutrophils. In addition, we found that ZNF765 was associated with m6A modification, which may affect the progression of HCC. Finally, drug sensitivity testing found that patients with HCC were sensitive to 20 drugs when they expressed high levels of ZNF765. In conclusion, ZNF765 may be a prognostic biomarker related to cell cycle, immune infiltration, m6A modification, and drug sensitivity for hepatocellular carcinoma.
    Keywords:  ZNF765; biomarker; hepatocellular carcinoma; immune infiltration; prognosis
    DOI:  https://doi.org/10.18632/aging.204827
  21. J Cell Mol Med. 2023 Jul 05.
    RNA m5C methylation orchestrates BLCA progression via macrophage reprogramming.
    Dali Yan, Yongsong Xie, Liyuan Huang, Yi Zhang, Runhuan Gu, Huaibing Xie, Xing Huang, Hao Luo.
      Recently, epigenetics showed essential roles in tumour microenvironment (TME) and immunotherapy response, however, the functions of RNA 5-methylcytosine (m5C) modification in TME remains unknown. According to 13 m5C regulators, we evaluated 412 BLCA patients from The Cancer Genome Atlas (TCGA) database. The m5C score was constructed by unsupervised clustering analysis and principal component analysis (PCA) algorithms. Gene set variation analysis (GSVA), ESTIMATE algorithm, and immunohistochemical (IHC) staining were performed. Macrophage chemotaxis assay was used to assess the M2 macrophages. Among the 412 patients, the frequency of mutation was 13%. m5C regulators was expressed significantly in BLCA tissue compared with normal tissue. Then, two m5C methylation modification patterns were identified with dissimilar TME cell infiltration patterns. The C1 alteration pattern in the m5C cluster was connected with better survival. In addition, we found that NSUN6 was highly correlated with recruitment of macrophages via bioinformatics and IHC. Further experiment validated that NSUN6 promoted HDAC10 expression by mediating m5C methylation, inhibited the transcription of macrophage-associated chemokines and thus inhibited the recruitment of M2 macrophages. The m5C score constructed by m5C modification pattern showed that high m5C score group had a better prognosis. This study uncovered the significant roles of m5C modifications in modulating the TME and indicated that NSUN6 could inhibit the recruitment of M2 macrophages via m5C methylation, which provided novel insight into epigenetic regulation of TME and clinical suggestions for immunotherapeutic strategies.
    DOI:  https://doi.org/10.1111/jcmm.17826
  22. Research (Wash D C). 2023 ;6 0184
    NOP2-mediated m5C Modification of c-Myc in an EIF3A-Dependent Manner to Reprogram Glucose Metabolism and Promote Hepatocellular Carcinoma Progression.
    Hao Zhang, Xiangyu Zhai, Yanfeng Liu, Zhijia Xia, Tong Xia, Gang Du, Huaxin Zhou, Dorothee Franziska Strohmer, Alexandr V Bazhin, Ziqiang Li, Xianqiang Wang, Bin Jin, Deliang Guo.
      Mitochondrial dysfunction and glycolysis activation are improtant hallmarks of hepatocellular carcinoma (HCC). NOP2 is an S-adenosyl-L-methionine-dependent methyltransferase that regulates the cell cycle and proliferation activities. In this study, found that NOP2 contributes to HCC progression by promoting aerobic glycolysis. Our results revealed that NOP2 was highly expressed in HCC and that it was associated with unfavorable prognosis. NOP2 knockout in combination with sorafenib enhanced sorafenib sensitivity, which, in turn, led to marked tumor growth inhibition. Mechanistically, we identified that NOP2 regulates the c-Myc expression in an m5C-modification manner to promote glycolysis. Moreover, our results revealed that m5C methylation induced c-Myc mRNA degradation in an eukaryotic translation initiation factor 3 subunit A (EIF3A)-dependent manner. In addition, NOP2 was found to increase the expression of the glycolytic genes LDHA, TPI1, PKM2, and ENO1. Furthermore, MYC associated zinc finger protein (MAZ) was identified as the major transcription factor that directly controlled the expression of NOP2 in HCC. Notably, in a patient-derived tumor xenograft (PDX) model, adenovirus-mediated knockout of NOP2 maximized the antitumor effect and prolonged the survival of PDX-bearing mice. Our cumulative findings revealed the novel signaling pathway MAZ/NOP2/c-Myc in HCC and uncovered the important roles of NOP2 and m5C modifications in metabolic reprogramming. Therefore, targeting the MAZ/NOP2/c-Myc signaling pathway is suggested to be a potential therapeutic strategy for the treatment of HCC.
    DOI:  https://doi.org/10.34133/research.0184
  23. Adv Sci (Weinh). 2023 Jul 05. e2300436
    Rna M6 a Methylation Regulates Glycolysis of Beige Fat and Contributes to Systemic Metabolic Homeostasis.
    Yu Li, Yankang Zhang, Ting Zhang, Xiaodan Ping, Dongmei Wang, Yanru Chen, Jian Yu, Caizhi Liu, Ziqi Liu, Yuhan Zheng, Yongfeng Yang, Chengchao Ruan, Dali Li, Zhenyu Du, Jiqiu Wang, Lingyan Xu, Xinran Ma.
      N6-methyladenosine (m6 A) modification has been implicated in the progression of obesity and metabolic diseases. However, its impact on beige fat biology is not well understood. Here, via m6 A-sequencing and RNA-sequencing, this work reports that upon beige adipocytes activation, glycolytic genes undergo major events of m6 A modification and transcriptional activation. Genetic ablation of m6 A writer Mettl3 in fat tissues reveals that Mettl3 deficiency in mature beige adipocytes leads to suppressed glycolytic capability and thermogenesis, as well as reduced preadipocytes proliferation via glycolytic product lactate. In addition, specific modulation of Mettl3 in beige fat via AAV delivery demonstrates consistently Mettl3's role in glucose metabolism, thermogenesis, and beige fat hyperplasia. Mechanistically, Mettl3 and m6 A reader Igf2bp2 control mRNA stability of key glycolytic genes in beige adipocytes. Overall, these findings highlight the significance of m6 A on fat biology and systemic energy homeostasis.
    Keywords:  Mettl3; N6-methyladenosine; beige fat; energy homeostasis; glycolysis; preadipocytes proliferation
    DOI:  https://doi.org/10.1002/advs.202300436
  24. Cell Signal. 2023 Jun 29. pii: S0898-6568(23)00202-4. [Epub ahead of print]109 110788
    LINC00426, a novel m6A-regulated long non-coding RNA, induces EMT in cervical cancer by binding to ZEB1.
    Siyuan Shen, Hua Jin, Xing Zhang, Yan Zhang, Xiuting Li, Wenjing Yan, Shuqian Xie, Bingjia Yu, Jing Hu, Haohan Liu, Xue Chen, Yamei Nie, Fengying Liu, Min Tang, Yun Gu, Shizhi Wang.
       PURPOSE: To explore the function and molecular mechanism of LINC00426 in Cervical Cancer (CC), and to explore the clinical treatment strategy of LINC00426 for CC.
    METHODS: Bioinformatics analysis was used to explore the expression of LINC00426 and patient prognosis of CC. Cell function experiments were conducted to explore the potential effect of LINC00426 on CC malignant phenotypes. The difference in m6A modification level between the high and low expression groups of LINC00426 was analyzed by detecting the total m6A level. The luciferase reporter assay was used to confirm the binding of miR-200a-3p to LINC00426. The RIP assay was used to confirm the binding of LINC00426 to ZEB1. Cell viability assay was performed to detect the effect of LINC00426 on cellular drug resistance.
    RESULTS: LINC00426 is up-regulated in CC, which can enhance the proliferation, migration and invasion of CC cells. METTL3 promotes the expression of LINC00426 by m6A methylation modification. In addition, the LINC00426/miR-200a-3p/ZEB1 axis affects the proliferation, migration, and invasion of CC by regulating the expression of EMT markers. Through the detection of cell viability, we observed that overexpression LINC00426 in cells resulted in resistance to cisplatin and bleomycin, and more sensitive to imatinib.
    CONCLUSION: LINC00426 is a cancer-promoting lncRNA related to m6A modification. The process of EMT in CC is regulated by the LINC00426/miR-200a/3p/ZEB1 axis. LINC00426 can affect the sensitivity of CC cells to chemotherapy drugs, and is expected to become a therapeutic target for CC.
    Keywords:  Cervical cancer; Drug resistance; LINC00426; ZEB1; m(6)A; miR-200a-3p
    DOI:  https://doi.org/10.1016/j.cellsig.2023.110788
  25. J Med Chem. 2023 Jul 07.
    Rational Design of RNA Demethylase FTO Inhibitors with Enhanced Antileukemia Drug-Like Properties.
    Pan Xiao, Zongliang Duan, Zeyu Liu, Liang Chen, Deyan Zhang, Lu Liu, Chen Zhou, Jianhua Gan, Ze Dong, Cai-Guang Yang.
      The fat mass and obesity-associated protein (FTO) is an RNA N6-methyladenosine (m6A) demethylase highly expressed in diverse cancers including acute myeloid leukemia (AML). To improve antileukemia drug-like properties, we have designed 44/ZLD115, a flexible alkaline side-chain-substituted benzoic acid FTO inhibitor derived from FB23. A combination of structure-activity relationship analysis and lipophilic efficiency-guided optimization demonstrates that 44/ZLD115 exhibits better drug-likeness than the previously reported FTO inhibitors, FB23 and 13a/Dac85. Then, 44/ZLD115 shows significant antiproliferative activity in leukemic NB4 and MOLM13 cell lines. Moreover, 44/ZLD115 treatment noticeably increases m6A abundance on the AML cell RNA, upregulates RARA gene expression, and downregulates MYC gene expression in MOLM13 cells, which are consistent with FTO gene knockdown. Lastly, 44/ZLD115 exhibits antileukemic activity in xenograft mice without substantial side effects. This FTO inhibitor demonstrates promising properties that can be further developed for antileukemia applications.
    DOI:  https://doi.org/10.1021/acs.jmedchem.3c00543
  26. Adv Sci (Weinh). 2023 Jul 03. e2301538
    Multi-Omics Analysis Reveals Translational Landscapes and Regulations in Mouse and Human Oocyte Aging.
    Jiana Huang, Peigen Chen, Lei Jia, Tingting Li, Xing Yang, Qiqi Liang, Yanyan Zeng, Jiawen Liu, Taibao Wu, Wenqi Hu, Kehkooi Kee, Haitao Zeng, Xiaoyan Liang, Chuanchuan Zhou.
      Abnormal resumption of meiosis and decreased oocyte quality are hallmarks of maternal aging. Transcriptional silencing makes translational control an urgent task during meiosis resumption in maternal aging. However, insights into aging-related translational characteristics and underlying mechanisms are limited. Here, using multi-omics analysis of oocytes, it is found that translatomics during aging is related to changes in the proteome and reveals decreased translational efficiency with aging phenotypes in mouse oocytes. Translational efficiency decrease is associated with the N6-methyladenosine (m6A) modification of transcripts. It is further clarified that m6A reader YTHDF3 is significantly decreased in aged oocytes, inhibiting oocyte meiotic maturation. YTHDF3 intervention perturbs the translatome of oocytes and suppress the translational efficiency of aging-associated maternal factors, such as Hells, to affect the oocyte maturation. Moreover, the translational landscape is profiled in human oocyte aging, and the similar translational changes of epigenetic modifications regulators between human and mice oocyte aging are observed. In particular, due to the translational silence of YTHDF3 in human oocytes, translation activity is not associated with m6A modification, but alternative splicing factor SRSF6. Together, the findings profile the specific translational landscapes during oocyte aging in mice and humans, and uncover non-conservative regulators on translation control in meiosis resumption and maternal aging.
    Keywords:  Hells; YTHDF3; m6A modifications; oocyte aging; translatomics
    DOI:  https://doi.org/10.1002/advs.202301538
  27. Clin Epigenetics. 2023 Jul 05. 15(1): 109
    FTO-dependent m6A regulates muscle fiber remodeling in an NFATC1-YTHDF2 dependent manner.
    Wengang Wang, Xueming Du, Ming Luo, Ningning Yang.
       BACKGROUND: Adolescent idiopathic scoliosis (AIS) is characterized by low lean mass without vertebral deformity. The cause-and-effect relationship between scoliosis and paraspinal muscle imbalance has long puzzled researchers. Although FTO has been identified as a susceptibility gene for AIS, its potential role in the asymmetry of paraspinal muscles has not been fully elucidated.
    METHODS: We investigated the role of Fto in murine myoblast proliferation, migration, and myogenic differentiation. We examined its precise regulatory influence on murine muscle fiber remodeling in vitro and in vivo. We identified the downstream target gene of Fto by screening key regulators of murine muscle fiber remodeling and identified its m6A reader. Deep paraspinal muscle samples were obtained from the concave and convex sides of AIS patients with or without Schroth exercises, and congenital scoliosis served as a control group. We compared the content of type I fibers, expression patterns of fast- and slow-type genes, and levels of FTO expression.
    RESULTS: FTO contributed to maintain the formation of murine slow-twitch fibers both in vitro and in vivo. These effects were mediated by the demethylation activity of FTO, which specifically demethylated NFATC1 and prevented YTHDF2 from degrading it. We found a significant reduction in type I fibers, mRNA levels of MYH7 and MYH7B, and expression of FTO on the concave side of AIS. The percentage of type I fibers showed a positive correlation with the expression level of FTO. The asymmetric patterns observed in AIS were consistent with those seen in congenital scoliosis, and the asymmetry of FTO expression and fiber type in AIS was largely restored by Schroth exercises.
    CONCLUSIONS: FTO supports the formation of murine slow-twitch fibers in an NFATC1-YTHDF2 dependent manner. The consistent paraspinal muscle features seen in AIS and congenital scoliosis, as well as the reversible pattern of muscle fibers and expression of FTO in AIS suggest that FTO may contribute to the muscle fiber remodeling secondary to scoliosis.
    Keywords:  Adolescent idiopathic scoliosis; FTO; Muscle fiber remodeling; m6A demethylation
    DOI:  https://doi.org/10.1186/s13148-023-01526-5
  28. Int J Biol Markers. 2023 Jul 02. 3936155231184908
    Prognostic significance of N6-methyladenosine-modified related chemotransferase METTL3 in gastric carcinoma: Evidence from meta-analysis.
    Chenglou Zhu, Qiong Wu, Yan Xu, Jichun Ma, Yongli Hu, Junhong Wang, Zhenhua Gao, Mingxu Da.
       BACKGROUND: N6-methyladenosine (m6A) methylation is known as the research hotspot for tumor epimodification, and its associated methyltransferase-like3 (METTL3) is significantly differentially expressed in gastric carcinoma, but its clinical value has not been summarized. This meta-analysis aimed to evaluate the prognostic significance of METTL3 in gastric carcinoma.
    MATERIAL AND METHODS: Databases, including PubMed, EMBASE (Ovid platform), Science Direct, Scopus, MEDLINE, Google Scholar, Web of Science, and Cochrane Library, were used to identify relevant eligible studies. The endpoints included overall survival, progression-free survival, recurrence-free survival, post-progression survival, and disease-free survival. Hazard ratios (HR) with 95% confidence intervals (CI) were used to correlate METTL3 expression with prognosis. Subgroup and sensitivity analyses were performed.
    RESULTS: Seven eligible studies involving 3034 gastric carcinoma patients were recruited for this meta-analysis. The analysis showed that high METTL3 expression was associated with significantly poorer overall survival (HR  =  2.37, 95% CI 1.66-3.39, P < 0.01) and unfavorable disease-free survival (HR  =  2.58, 95% CI 1.97-3.38, P  < 0.01), as did unfavorable progression-free survival (HR  =  1.48, 95% CI 1.19-1.84, P  < 0.01)/recurrence-free survival (HR  =  2.62, 95% CI 1.93-5.62, P  < 0.01)/post-progression survival (HR  =  1.53, 95% CI 1.22-1.91, P  < 0.01). Subgroup analysis found that high METTL3 expression was associated with worse overall survival in patients with Chinese (HR  =  2.21, 95% CI 1.48-3.29, P  < 0.01), in studies with sample source from formalin-fixed, paraffin-embedded tissues (HR  =  2.66, 95% CI 1.79-3.94, P  < 0.01), and the reported directly from articles group (HR  =  2.42, 95% CI 1.66-3.53, P  < 0.01). The subgroup analysis that was performed based on sample size, detected method, and follow-up showed the same results.
    CONCLUSIONS: High expression of METTL3 predicts poor prognosis in gastric carcinoma, indicating promise for METTL3 as a prognostic biomarker.Systematic review registration: https://www.crd.york.ac.uk/prospero, ID = CRD42023408519.
    Keywords:  Gastric carcinoma; N6-methyladenosine; meta-analysis; methyltransferase-like3; prognostic biomarker
    DOI:  https://doi.org/10.1177/03936155231184908
  29. BMC Bioinformatics. 2023 Jul 04. 24(1): 274
    The prognostic value and immune landscaps of m6A/m5C-related lncRNAs signature in the low grade glioma.
    Ran Li, Haiyan Chen, Chaoxi Li, Yiwei Qi, Kai Zhao, Junwen Wang, Chao You, Haohao Huang.
       BACKGROUND: N6-methyladenosine (m6A) and 5-methylcytosine (m5C) are the main RNA methylation modifications involved in the oncogenesis of cancer. However, it remains obscure whether m6A/m5C-related long non-coding RNAs (lncRNAs) affect the development and progression of low grade gliomas (LGG).
    METHODS: We summarized 926 LGG tumor samples with RNA-seq data and clinical information from The Cancer Genome Atlas and Chinese Glioma Genome Atlas. 105 normal brain samples with RNA-seq data from the Genotype Tissue Expression project were collected for control. We obtained a molecular classification cluster from the expression pattern of sreened lncRNAs. The least absolute shrinkage and selection operator Cox regression was employed to construct a m6A/m5C-related lncRNAs prognostic signature of LGG. In vitro experiments were employed to validate the biological functions of lncRNAs in our risk model.
    RESULTS: The expression pattern of 14 sreened highly correlated lncRNAs could cluster samples into two groups, in which various clinicopathological features and the tumor immune microenvironment were significantly distinct. The survival time of cluster 1 was significantly reduced compared with cluster 2. This prognostic signature is based on 8 m6A/m5C-related lncRNAs (GDNF-AS1, HOXA-AS3, LINC00346, LINC00664, LINC00665, MIR155HG, NEAT1, RHPN1-AS1). Patients in the high-risk group harbored shorter survival times. Immunity microenvironment analysis showed B cells, CD4 + T cells, macrophages, and myeloid-derived DC cells were significantly increased in the high-risk group. Patients in high-risk group had the worse overall survival time regardless of followed TMZ therapy or radiotherapy. All observed results from the TCGA-LGG cohort could be validated in CGGA cohort. Afterwards, LINC00664 was found to promote cell viability, invasion and migration ability of glioma cells in vitro.
    CONCLUSION: Our study elucidated a prognostic prediction model of LGG by 8 m6A/m5C methylated lncRNAs and a critical lncRNA regulation function involved in LGG progression. High-risk patients have shorter survival times and a pro-tumor immune microenvironment.
    Keywords:  Immune landscape; Long non-coding RNA; Low grade glioma; Prognostic signature; RNA methylation
    DOI:  https://doi.org/10.1186/s12859-023-05386-x
  30. Pharmgenomics Pers Med. 2023 ;16 665-679
    Identification of Novel Prognostic Biomarkers That are Associated with Immune Microenvironment Based on GABA-Related Molecular Subtypes in Gastric Cancer.
    Beibei Wang, Linlin Huang, Shanliang Ye, Zhongwen Zheng, Shanying Liao.
       Background: Gamma-aminobutyric acid (GABA) plays an important role in tumorigenesis and progression. Despite this, the role of Reactome GABA receptor activation (RGRA) on gastric cancer (GC) remains unclear. This study was intended to screen RGRA-related genes in GC and investigate their prognostic value.
    Methods: GSVA algorithm was used to assess the score of RGRA. GC patients were divided into two subtypes based on the median score of RGRA. GSEA, functional enrichment analysis, and immune infiltration analysis were performed between the two subgroups. Then, differentially expressed analysis, and weighted gene co-expression network analysis (WGCNA) were used to identify RGRA-related genes. The prognosis and expression of core genes were analyzed and validated in the TCGA database, GEO database, and clinical samples. ssGSEA and ESTIMATE algorithms were used to assess the immune cell infiltration in the low- and high-core genes subgroups.
    Results: High-RGRA subtype had a poor prognosis and activated immune-related pathways, as well as an activated immune microenvironment. ATP1A2 was identified to be the core gene. The expression of ATP1A2 was associated with the overall survival rate and tumor stage, and its expression was down-regulated in GC patients. Furthermore, ATP1A2 expression was positively correlated with the level of immune cells, including B cells, CD8 T cells, cytotoxic cells, DC, eosinophils, macrophages, mast cells, NK cells, and T cells.
    Conclusion: Two RGRA-related molecular subtypes were identified that could predict the outcome in GC patients. ATP1A2 was a core immunoregulatory gene and was associated with prognosis and immune cell infiltration in GC.
    Keywords:  GABA; gastric cancer; immune response; molecular subtypes; prognostic marker
    DOI:  https://doi.org/10.2147/PGPM.S411862
  31. Cell Biosci. 2023 Jul 03. 13(1): 124
    Serine protease PRSS56, a novel cancer-testis antigen activated by DNA hypomethylation, promotes colorectal and gastric cancer progression via PI3K/AKT axis.
    Dandan Li, Lingyun Xia, Pan Huang, Zidi Wang, Qiwei Guo, Congcong Huang, Weidong Leng, Shanshan Qin.
       BACKGROUND: Cancer/testis (CT) antigens/genes are usually overexpressed in cancers and exhibit high immunogenicity, making them promising targets for immunotherapy and cancer vaccines. The role of serine protease PRSS56 in cancers remains unknown to date.
    METHODS: RNA sequencing studies were performed to screen CT genes in gastric cancer (GC) and colorectal cancer (CRC) cells exposed to DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-AZA-CdR). Bioinformatics analysis was conducted to analyze the correlation between PRSS56 expression and DNA methylation. Functional experiments were performed to explore the biological function of PRSS56 in GC and CRC.
    RESULTS: In this study, we identified the testis-specific serine proteases PRSS56 as a novel CT antigen. PRSS56 was frequently overexpressed in various cancers, especially in gastrointestinal cancer. PRSS56 expression was negatively associated with promoter DNA methylation level, and positively associated with gene body methylation level. PRSS56 expression was significantly activated in colorectal and gastric cancer cells exposed to DNA methyltransferase inhibitors. Importantly, our finding highlights that the decreased methylation level of the CpG site cg10242318 in the PRSS56 promoter region resulted in its overexpression in GC and CRC. Additionally, functional assays verified that PRSS56 overexpression activated PI3K-AKT signaling in GC and CRC.
    CONCLUSION: Serine protease PRSS56 is a novel CT antigen that is reactivated in cancers by promoter DNA hypomethylation. PRSS56 functions oncogenic roles in GC and CRC by activating of PI3K/AKT axis. Our results presented here represent the first data on the function of the serine protease PRSS56 in cancers.
    Keywords:  Cancer/testis gene; DNA methylation; Serine protease; Tumor antigen
    DOI:  https://doi.org/10.1186/s13578-023-01060-0
  32. Front Genet. 2023 ;14 1140218
    m6A-related lncRNAs predict prognosis and indicate cell cycle in gastric cancer.
    Dong Wan, Lingnan He, Cheng Guo, Zishao Zhong, Xiaohan Yan, Jia Cao, Qinwei Xu, Haibin Zhang, Bensong Duan.
      Background: N6-methyladenosine (m6A) modification is a common epigenetic methylation modification of RNA, which plays an important role in gastric carcinogenesis and progression by regulating long non-coding RNA (lncRNA). This study is aimed to investigate the potential prognostic signatures of m6A -related lncRNAs in STAD. Methods: The m6A-related lncRNAs with the most significant impact on gastric cancer prognosis in the TCGA database were identified by bioinformatics and machine learning methods. The m6A-related lncRNA prognostic model (m6A-LPS) and nomogram was constructed by Cox regression analysis with the minimum absolute contraction and selection operator (LASSO) algorithm. The functional enrichment analysis of m6A-related lncRNAs was also investigated. The miRTarBase, miRDB and TargetScan databases were utilized to establish a prognosis-related network of competing endogenous RNA (ceRNA) by bioinformatics methods. The correlation of AL391152.1 expressions and cell cycle were experimentally testified by qRT-PCR and flow cytometry. Results: In total, 697 lncRNAs that were identified as m6A-related lncRNAs in GC samples. The survival analysis showed that 18 lncRNAs demonstrated prognostic values. A risk model with 11 lncRNAs was established by Lasso Cox regression, and can predict the prognosis of GC patients. Cox regression analysis and ROC curve indicated that this lncRNA prediction model was an independent risk factor for survival rates. Functional enrichment analysis and ceRNA network revealed that the nomogram was notably associated with cell cycle. qRT-PCR and flow cytometry revealed that downregulation of GC m6A-related lncRNA AL391152.1 could decrease cyclins expression in SGC7901 cells. Conclusion: A m6A-related lncRNAs prognostic model was established in this study, which can be applied to predict prognosis and cell cycle in gastric cancer.
    Keywords:  N6-methyladenosine; cell cycle; gastric cancer; long non-coding RNA; prognosis
    DOI:  https://doi.org/10.3389/fgene.2023.1140218
  33. Mol Cancer. 2023 Jul 01. 22(1): 103
    Enhancement of TKI sensitivity in lung adenocarcinoma through m6A-dependent translational repression of Wnt signaling by circ-FBXW7.
    Kai Li, Zi-Yang Peng, Rui Wang, Xiang Li, Ning Du, Da-Peng Liu, Jia Zhang, Yun-Feng Zhang, Lei Ma, Ye Sun, Shou-Ching Tang, Hong Ren, Yi-Ping Yang, Xin Sun.
       BACKGROUND: Tyrosine kinase inhibitors (TKIs) that specifically target mutational points in the EGFR gene have significantly reduced suffering and provided greater relief to patients with lung adenocarcinoma (LUAD). The third-generation EGFR-TKI, Osimertinib, has been successfully employed in clinical treatments to overcome resistance to both original and acquired T790M and L858R mutational points. Nevertheless, the issue of treatment failure response has emerged as an insurmountable problem.
    METHODS: By employing a combination of multiple and integrated approaches, we successfully identified a distinct population within the tumor group that plays a significant role in carcinogenesis, resistance, and recurrence. Our research suggests that addressing TKI resistance may involve targeting the renewal and repopulation of stem-like cells. To investigate the underlying mechanisms, we conducted RNA Microarray and m6A Epi-Transcriptomic Microarray analyses, followed by assessment of transcription factors. Additionally, we specifically designed a tag to detect the polypeptide circRNA-AA, and its expression was confirmed through m6A regulations.
    RESULTS: We initially identified unique molecular signatures present in cancer stem cells that contributed to poor therapeutic responses. Activation of the alternative Wnt pathway was found to sustain the renewal and resistant status of these cells. Through bioinformatics analysis and array studies, we observed a significant decrease in the expression of circFBXW7 in Osimertinib-resistant cell lines. Notably, the abnormal expression pattern of circFBXW7 determined the cellular response to Osimertinib. Functional investigations revealed that circFBXW7 inhibits the renewal of cancer stem cells and resensitizes both resistant LUAD cells and stem cells to Osimertinib. In terms of the underlying mechanism, we discovered that circFBXW7 can be translated into short polypeptides known as circFBXW7-185AA. These polypeptides interact with β-catenin in an m6A-dependent manner. This interaction leads to reduced stability of β-catenin by inducing subsequent ubiquitination, thereby suppressing the activation of canonical Wnt signaling. Additionally, we predicted that the m6A reader, YTHDF3, shares common binding sites with hsa-Let-7d-5p. Enforced expression of Let-7d post-transcriptionally decreases the levels of YTHDF3. The repression of Let-7d by Wnt signaling releases the stimulation of m6A modification by YTHDF3, promoting the translation of circFBXW7-185AA. This creates a positive feedback loop contributing to the cascade of cancer initiation and promotion.
    CONCLUSIONS: Our bench study, in vivo experiments, and clinical validation have unequivocally shown that circFBXW7 effectively inhibits the abilities of LUAD stem cells and reverses resistance to TKIs by modulating Wnt pathway functions through the action of circFBXW7-185AA on β-catenin ubiquitination and inhibition. The regulatory role of circRNA in Osimertinib treatment has been rarely reported, and our findings reveal that this process operates under the influence of m6A modification. These results highlight the tremendous potential of this approach in enhancing therapeutic strategies and overcoming resistance to multiple TKI treatments.
    Keywords:  Lung adenocarcinoma; Therapy resistance; Translated circRNAs; Tyrosine kinase inhibitor; m6A modification
    DOI:  https://doi.org/10.1186/s12943-023-01811-0
  34. Int J Biol Sci. 2023 ;19(10): 3115-3127
    FABP5 suppresses colorectal cancer progression via mTOR-mediated autophagy by decreasing FASN expression.
    Mujie Ye, Chunhua Hu, Tiaotiao Chen, Ping Yu, Jinhao Chen, Feiyu Lu, Lin Xu, Yuan Zhong, Lijun Yan, Jingbao Kan, Jianan Bai, Xiaolin Li, Ye Tian, Qiyun Tang.
      Lipid metabolism plays an important role in the occurrence and development of cancer, in particular, digestive system tumors such as colon cancer. Here, we investigated the role of the fatty acid-binding protein 5 (FABP5) in colorectal cancer (CRC). We observed marked down-regulation of FABP5 in CRC. Data from functional assays revealed inhibitory effects of FABP5 on cell proliferation, colony formation, migration, invasion as well as tumor growth in vivo. In terms of mechanistic insights, FABP5 interacted with fatty acid synthase (FASN) and activated the ubiquitin proteasome pathway, leading to a decrease in FASN expression and lipid accumulation, moreover, suppressing mTOR signaling and facilitating cell autophagy. Orlistat, a FASN inhibitor, exerted anti-cancer effects both in vivo and in vitro. Furthermore, the upstream RNA demethylase ALKBH5 positively regulated FABP5 expression via an m6A-independent mechanism. Overall, our collective findings offer valuable insights into the critical role of the ALKBH5/FABP5/FASN/mTOR axis in tumor progression and uncover a potential mechanism linking lipid metabolism to development of CRC, providing novel therapeutic targets for future interventions.
    Keywords:   FASN; Autophagy; Colorectal cancer; FABP5; Lipid metabolism; N6-methyladenosine; Orlistat
    DOI:  https://doi.org/10.7150/ijbs.85285
  35. Nat Commun. 2023 07 05. 14(1): 3966
    UHRF1 is a mediator of KRAS driven oncogenesis in lung adenocarcinoma.
    Kaja Kostyrko, Marta Román, Alex G Lee, David R Simpson, Phuong T Dinh, Stanley G Leung, Kieren D Marini, Marcus R Kelly, Joshua Broyde, Andrea Califano, Peter K Jackson, E Alejandro Sweet-Cordero.
      KRAS is a frequent driver in lung cancer. To identify KRAS-specific vulnerabilities in lung cancer, we performed RNAi screens in primary spheroids derived from a Kras mutant mouse lung cancer model and discovered an epigenetic regulator Ubiquitin-like containing PHD and RING finger domains 1 (UHRF1). In human lung cancer models UHRF1 knock-out selectively impaired growth and induced apoptosis only in KRAS mutant cells. Genome-wide methylation and gene expression analysis of UHRF1-depleted KRAS mutant cells revealed global DNA hypomethylation leading to upregulation of tumor suppressor genes (TSGs). A focused CRISPR/Cas9 screen validated several of these TSGs as mediators of UHRF1-driven tumorigenesis. In vivo, UHRF1 knock-out inhibited tumor growth of KRAS-driven mouse lung cancer models. Finally, in lung cancer patients high UHRF1 expression is anti-correlated with TSG expression and predicts worse outcomes for patients with KRAS mutant tumors. These results nominate UHRF1 as a KRAS-specific vulnerability and potential target for therapeutic intervention.
    DOI:  https://doi.org/10.1038/s41467-023-39591-2
  36. Aging (Albany NY). 2023 Jul 06. 15
    Clinical significance, tumor immune landscape and immunotherapy responses of ADAR in pan-cancer and its association with proliferation and metastasis of bladder cancer.
    Hao Yu, Kexin Bai, Yidong Cheng, Jiancheng Lv, Qiang Song, Haiwei Yang, Qiang Lu, Xiao Yang.
       BACKGROUND: ADAR is an enzyme involved in adenosine-inosine RNA editing. However, the role of ADAR in tumorigenesis, progression, and immunotherapy has not been fully elucidated.
    METHODS: The TCGA, GTEx and GEO databases were extensively utilized to explore the expression level of ADAR across cancers. Combined with the clinical information of patients, the risk profile of ADAR in various cancers was delineated. We identified pathways enriched in ADAR and their related genes and explored the association between ADAR expression and the cancer immune microenvironment score and response to immunotherapy. Finally, we specifically explored the potential value of ADAR in the treatment of the bladder cancer immune response and verified the critical role of ADAR in the development and progression of bladder cancer through experiments.
    RESULTS: ADAR is highly expressed in most cancers at both the RNA and protein level. ADAR is associated with the aggressiveness of some cancers, especially bladder cancer. In addition, ADAR is associated with immune-related genes, especially immune checkpoint genes, in the tumor immune microenvironment. Moreover, ADAR expression is positively correlated with tumor mutation burden and microsatellite instability in a variety of cancers, indicating that ADAR could be used as a biomarker of immunotherapy. Finally, we demonstrated that ADAR is a key pathogenic factor in bladder cancer. ADAR promoted proliferation and metastasis of bladder cancer cells.
    CONCLUSION: ADAR regulates the tumor immune microenvironment and can be used as a biomarker of the tumor immunotherapy response, providing a novel strategy for the treatment of tumors, especially bladder cancer.
    Keywords:  ADAR; bladder cancer; cancer; immunotherapy; tumor immune microenvironment
    DOI:  https://doi.org/10.18632/aging.204853
  37. Front Aging Neurosci. 2023 ;15 1161068
    Identification and prediction of m7G-related Alzheimer's disease subtypes: insights from immune infiltration and machine learning models.
    Chao Ma, Jian Li, Yuhua Chi, Xuan Sun, Maoquan Yang, Xueqin Sui.
       Introduction: Alzheimer's disease (AD) is a complex and progressive neurodegenerative disorder that primarily affects older individuals. N7-methylguanosine (m7G) is a common RNA chemical modification that impacts the development of numerous diseases. Thus, our work investigated m7G-related AD subtypes and established a predictive model.
    Methods: The datasets for AD patients, including GSE33000 and GSE44770, were obtained from the Gene Expression Omnibus (GEO) database, which were derived from the prefrontal cortex of the brain. We performed differential analysis of m7G regulators and examined the immune signatures differences between AD and matched-normal samples. Consensus clustering was employed to identify AD subtypes based on m7G-related differentially expressed genes (DEGs), and immune signatures were explored among different clusters. Furthermore, we developed four machine learning models based on the expression profiles of m7G-related DEGs and identified five important genes from the optimal model. We evaluated the predictive power of the 5-gene-based model using an external AD dataset (GSE44770).
    Results: A total of 15 genes related to m7G were found to be dysregulated in patients with AD compared to non-AD patients. This finding suggests that there are differences in immune characteristics between these two groups. Based on the differentially expressed m7G regulators, we categorized AD patients into two clusters and calculated the ESTIMATE score for each cluster. Cluster 2 exhibited a higher ImmuneScore than Cluster 1. We performed the receiver operating characteristic (ROC) analysis to compare the performance of four models, and we found that the Random Forest (RF) model had the highest AUC value of 1.000. Furthermore, we tested the predictive efficacy of a 5-gene-based RF model on an external AD dataset and obtained an AUC value of 0.968. The nomogram, calibration curve, and decision curve analysis (DCA) confirmed the accuracy of our model in predicting AD subtypes.
    Conclusion: The present study systematically examines the biological significance of m7G methylation modification in AD and investigates its association with immune infiltration characteristics. Furthermore, the study develops potential predictive models to assess the risk of m7G subtypes and the pathological outcomes of patients with AD, which can facilitate risk classification and clinical management of AD patients.
    Keywords:  AD subtypes; Alzheimer’s disease; immune infiltration; m7G methylation; machine learning; predictive model
    DOI:  https://doi.org/10.3389/fnagi.2023.1161068
  38. Sci Rep. 2023 07 03. 13(1): 10755
    METTL5 serves as a diagnostic and prognostic biomarker in hepatocellular carcinoma by influencing the immune microenvironment.
    Lei Wang, Jin-Lin Peng.
      Despite the abnormal expression of 18S rRNA m6A methyltransferase METTL5 being reported in some types of human malignancies, but its effect on hepatocellular carcinoma (HCC) remains to be unclear. This study aims to elucidate the influences of METTL5 on the carcinogenesis and progression of HCC. Expressions of METTL5 gene, transcript, protein, and promoter methylation in HCC were examined through multiple databases, c-BioPortal was used to confirm the genomic alterations of METTL5, the biological functions, target networks of kinases and microRNAs of METTL5, and its interactive differential genes were investigated through LinkedOmics. The possible correlation of METTL5 with the tumor-related infiltration of immune cells for HCC were explored comprehensively by using the online tools of TIMER and TISIDB. Expressions of METTL5 gene, mRNA, and protein were considerably overexpressed in HCC samples in comparison with healthy samples. The high methylation of the METTL5 promoter was observed in HCC tissues. Elevated METTL5 expression exhibited unfavorable survival outcomes in HCC patients. METTL5 expression were enriched in the signaling pathways of ribosome and oxidative phosphorylation, mismatch repair, and spliceosome through the involvement of several cancer-related kinases and miRNAs. The METTL5 expression has a positive correlation with the infiltration degree of B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells in HCC. Marker genes of tumor immune-infiltrated cells have strong connection with METTL5. Furthermore, the upregulation of METTL5 was strongly correlated with the immune regulation of immunomodulators, chemokines, and chemokine receptors in the immune microenvironment. The oncogenesis and development of HCC are closely related to METTL5 expression, and the overexpression of METTL5 resulted in the poor survival outcome of HCC patients by regulating tumor immune microenvironment.
    DOI:  https://doi.org/10.1038/s41598-023-37807-5
  39. Clin Transl Oncol. 2023 Jul 05.
    The role of the mitochondrial ribosomal protein family in detecting hepatocellular carcinoma and predicting prognosis, immune features, and drug sensitivity.
    Jin-Wei Zhao, Wei-Yi Zhao, Xin-Hua Cui, Lin Xing, Jia-Cheng Shi, Lu Yu.
       BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumors, with a slow onset, rapid progression, and frequent recurrence. Previous research has implicated mitochondrial ribosomal genes in the development, metastasis, and prognosis of various cancers. However, further research is necessary to establish a link between mitochondrial ribosomal protein (MRP) family expression and HCC diagnosis, prognosis, ferroptosis-related gene (FRG) expression, m6A modification-related gene expression, tumor immunity, and drug sensitivity.
    METHODS: Bioinformatics resources were used to analyze data from patients with HCC retrieved from the TCGA, ICGC, and GTEx databases (GEPIA, UALCAN, Xiantao tool, cBioPortal, STRING, Cytoscape, TISIDB, and GSCALite).
    RESULTS: Among the 82 MRP family members, 14 MRP genes (MRPS21, MRPS23, MRPL9, DAP3, MRPL13, MRPL17, MRPL24, MRPL55, MRPL16, MRPL14, MRPS17, MRPL47, MRPL21, and MRPL15) were significantly upregulated differentially expressed genes (DEGs) in HCC tumor samples in comparison to normal samples. Receiver-operating characteristic curve analysis indicated that all 14 DEGs show good diagnostic performance. Furthermore, TCGA analysis revealed that the mRNA expression of 39 MRPs was associated with overall survival (OS) in HCC. HCC was divided into two molecular subtypes (C1 and C2) with distinct prognoses using clustering analysis. The clusters showed different FRG expression and m6A methylation profiles and immune features, and prognostic models showed that the model integrating 5 MRP genes (MRPS15, MRPL3, MRPL9, MRPL36, and MRPL37) and 2 FRGs (SLC1A5 and SLC5A11) attained a greater clinical net benefit than three other prognostic models. Finally, analysis of the CTRP and GDSC databases revealed several potential drugs that could target prognostic MRP genes.
    CONCLUSION: We identified 14 MRP genes as HCC diagnostic markers. We investigated FRG and m6A modification-related gene expression profiles and immune features in patients with HCC, and developed and validated a model incorporating MRP and FRG expression that accurately and reliably predicts HCC prognosis and may predict disease progression and treatment response.
    Keywords:  Diagnosis; Drug sensitivity; Hepatocellular carcinoma (HCC); Immune; Mitochondrial ribosomal protein (MRP) family; Prognosis
    DOI:  https://doi.org/10.1007/s12094-023-03269-4
  40. Front Med (Lausanne). 2023 ;10 1112573
    Endoglin and squamous cell carcinomas.
    Sarah K Hakuno, Stefanus G T Janson, Marjolijn D Trietsch, Manon de Graaf, Eveline de Jonge-Muller, Stijn Crobach, Tom J Harryvan, Jurjen J Boonstra, Winand N M Dinjens, Marije Slingerland, Lukas J A C Hawinkels.
      Despite the fact that the role of endoglin on endothelial cells has been extensively described, its expression and biological role on (epithelial) cancer cells is still debatable. Especially its function on squamous cell carcinoma (SCC) cells is largely unknown. Therefore, we investigated SCC endoglin expression and function in three types of SCCs; head and neck (HNSCC), esophageal (ESCC) and vulvar (VSCC) cancers. Endoglin expression was evaluated in tumor specimens and 14 patient-derived cell lines. Next to being expressed on angiogenic endothelial cells, endoglin is selectively expressed by individual SCC cells in tumor nests. Patient derived HNSCC, ESCC and VSCC cell lines express varying levels of endoglin with high interpatient variation. To assess the function of endoglin in signaling of TGF-β ligands, endoglin was overexpressed or knocked out or the signaling was blocked using TRC105, an endoglin neutralizing antibody. The endoglin ligand BMP-9 induced strong phosphorylation of SMAD1 independent of expression of the type-I receptor ALK1. Interestingly, we observed that endoglin overexpression leads to strongly increased soluble endoglin levels, which in turn decreases BMP-9 signaling. On the functional level, endoglin, both in a ligand dependent and independent manner, did not influence proliferation or migration of the SCC cells. In conclusion, these data show endoglin expression on individual cells in the tumor nests in SCCs and a role for (soluble) endoglin in paracrine signaling, without directly affecting proliferation or migration in an autocrine manner.
    Keywords:  BMP-9; TGF-β; TRC105; endoglin; squamous cell carcinoma
    DOI:  https://doi.org/10.3389/fmed.2023.1112573
  41. J Cell Biochem. 2023 Jul 02.
    PPARγ agonist inhibits c-Myc-mediated colorectal cancer tumor immune escape.
    Liuqian Xu, Suning Che, Huiqing Chen, Qian Liu, Juanjuan Shi, Jianhua Jin, Yongzhong Hou.
      As a master transcription factor, c-Myc plays an important role in promoting tumor immune escape. In addition, PPARγ (peroxisome proliferator-activated receptor γ) regulates cell metabolism, inflammation, and tumor progression, while the effect of PPARγ on c-Myc-mediated tumor immune escape is still unclear. Here we found that cells treated with PPARγ agonist pioglitazone (PIOG) reduced c-Myc protein expression in a PPARγ-dependent manner. qPCR analysis showed that PIOG had no significant effect on c-Myc gene levels. Further analysis showed that PIOG decreased c-Myc protein half-life. Moreover, PIOG increased the binding of c-Myc to PPARγ, and induced c-Myc ubiquitination and degradation. Importantly, c-Myc increased PD-L1 and CD47 immune checkpoint protein expression and promoted tumor immune escape, while PIOG inhibited this event. These findings suggest that PPARγ agonist inhibited c-Myc-mediated tumor immune escape by inducing its ubiquitination and degradation.
    Keywords:  PPARγ agonist; c-Myc; degradation; tumor suppression; ubiquitination
    DOI:  https://doi.org/10.1002/jcb.30437
  42. Nat Commun. 2023 07 03. 14(1): 3902
    Modeling and therapeutic targeting of inflammation-induced hepatic insulin resistance using human iPSC-derived hepatocytes and macrophages.
    Marko Groeger, Koji Matsuo, Emad Heidary Arash, Ashley Pereira, Dounia Le Guillou, Cindy Pino, Kayque A Telles-Silva, Jacquelyn J Maher, Edward C Hsiao, Holger Willenbring.
      Hepatic insulin resistance is recognized as a driver of type 2 diabetes and fatty liver disease but specific therapies are lacking. Here we explore the potential of human induced pluripotent stem cells (iPSCs) for modeling hepatic insulin resistance in vitro, with a focus on resolving the controversy about the impact of inflammation in the absence of steatosis. For this, we establish the complex insulin signaling cascade and the multiple inter-dependent functions constituting hepatic glucose metabolism in iPSC-derived hepatocytes (iPSC-Heps). Co-culture of these insulin-sensitive iPSC-Heps with isogenic iPSC-derived pro-inflammatory macrophages induces glucose output by preventing insulin from inhibiting gluconeogenesis and glycogenolysis and activating glycolysis. Screening identifies TNFα and IL1β as the mediators of insulin resistance in iPSC-Heps. Neutralizing these cytokines together restores insulin sensitivity in iPSC-Heps more effectively than individual inhibition, reflecting specific effects on insulin signaling and glucose metabolism mediated by NF-κB or JNK. These results show that inflammation is sufficient to induce hepatic insulin resistance and establish a human iPSC-based in vitro model to mechanistically dissect and therapeutically target this metabolic disease driver.
    DOI:  https://doi.org/10.1038/s41467-023-39311-w
  43. J Cell Mol Med. 2023 Jul 03.
    A negative feedback loop between KLF9 and the EMT program dictates metastasis of hepatocellular carcinoma.
    Tao Wang, Limin Feng, Zhong Shi, Lixian Yang, Xiaofu Yu, Jinsong Wu, Jirui Sun, Jinku Zhang, Yuxiong Feng, Weilin Wang.
      Metastasis is the primary cause of death of hepatocellular carcinoma (HCC), while the mechanism underlying this severe disease remains largely unclear. The Kruppel-like factor (KLF) family is one of the largest transcription factor families that control multiple physiologic and pathologic processes by governing the cellular transcriptome. To identify metastatic regulators of HCC, we conducted gene expression profiling on the MHCC97 cell series, a set of subclones of the original MHCC97 that was established by in vivo metastasis selection therefore harbouring differential metastatic capacities. We found that the expression of KLF9, a member of the KLF family, was dramatically repressed in the metastatic progeny clone of the MHCC97 cells. Functional studies revealed overexpression of KLF9 suppressed HCC migration in vitro and metastasis in vivo, while knockdown of KLF9 was sufficient to promote cell migration and metastasis accordingly. Mechanistically, we found the expression of KLF9 can reverse the pro-metastatic epithelial-mesenchymal transition (EMT) program via direct binding to the promoter regions of essential mesenchymal genes, thus repressing their expression. Interestingly, we further revealed that KLF9 was, in turn, directly suppressed by a mesenchymal transcription factor Slug, suggesting an intriguing negative feedback loop between KLF9 and the EMT program. Using clinical samples, we found that KLF9 was not only downregulated in HCC tissue compared to its normal counterparts but also further reduced in the HCC samples of whom had developed metastatic lesions. Together, we established a critical transcription factor that represses HCC metastasis, which is clinically and mechanically significant in HCC therapies.
    Keywords:  KLF9; epithelial-mesenchymal transition; hepatocellular carcinoma; metastasis; slug
    DOI:  https://doi.org/10.1111/jcmm.17823
  44. Horm Metab Res. 2023 Jul 03.
    CircRNA SCAR Improves High-Glucose-Induced Mitochondrial Dysfunction and Permeability Damage in Retinal Microvascular Endothelial Cells.
    Rong Wu, Sheng Huang, Jin-Feng Xie, Nian-Lian Wen, Min Wen, Su-E Zhong.
      This study was designed to assess the role and mechanism of circRNA SCAR in human retinal microvascular endothelial cells (hRMVECs) treated with high glucose. Quantitative real-time polymerase chain reaction (qRT-PCR) and cell counting kit 8 (CCK-8) were used to detect the effects of different concentrations of glucose on circRNA SCAR expression and cell proliferation in hRMVECs. Cell viability, levels of oxygen species (ROS), malondialdehyde (MDA) and adenosine triphosphate (ATP), as well as activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in the transfected hRMVECs in each group were detected using CCK-8 and their corresponding detection kits. Changes in mtDNA copy number in high-glucose-induced hRMVECs were observed by qRT-PCR. Additionally, western blot was applied to detect effect of overexpressing circRNA SCAR on the expression levels of mitochondrial function-related proteins (Drp1 and Fis1) and cell permeability-related proteins (claudin-5, occludin and ZO-1) in hRMVECs under high-glucose concentration. According to experimental results, high glucose significantly downregulated circRNA SCAR expression and inhibited cell proliferation in hRMVECs. Instead, overexpression of this circRNA SCAR promoted cell proliferation, reduced levels of ROS, MDA and ATP, and increased SOD and CAT activities in hRMVECs under high-glucose concentration. Also, circRNA SCAR overexpression reversed the high-glucose-induced decrease in mtDNA copy number as well as, high-glucose-induced upregulation of Drp1 and Fis1 protein expression and downregulation of claudin-5, occludin and ZO-1 protein expression in hRMVECs. In summary, circRNA SCAR promotes the proliferation of hRMVECs under high-glucose concentration, alleviates oxidative stress induced by high glucose, and improves mitochondrial function and permeability damage.
    DOI:  https://doi.org/10.1055/a-2108-9820
  45. Clin Transl Med. 2023 07;13(7): e1316
    Runx2 activates hepatic stellate cells to promote liver fibrosis via transcriptionally regulating Itgav expression.
    Li Zhong, Jinqiu Zhao, Lu Huang, Yi Liu, Xiaoxiao Pang, Ke Zhan, Shan Li, Qian Xue, Xiaoli Pan, Liang Deng.
       BACKGROUNDS AND AIMS: As a central event during liver fibrosis, hepatic stellate cells (HSC) have been thought to be a potential therapeutic target for liver fibrosis. Previous studies have shown that runt-related transcription factor 2 (Runx2) is associated with the development of non-alcoholic fatty liver disease, while its specific role in HSC activation and hepatic fibrosis remains elusive.
    APPROACH AND RESULTS: In this study, we found that Runx2 expression was significantly upregulated in human liver fibrosis with different aetiologies. Runx2 expression was also gradually elevated in mouse liver during fibrosis, and Runx2 was mainly expressed in the activated HSC. Knockdown of Runx2 in HSC markedly alleviated CCl4 -induced, 3,5-diethoxycarbonyl-1,4-dihydrocollidine-induced or methionine-choline deficient (MCD)-induced liver fibrosis, while hepatic overexpression of Runx2 via HBAAV-Runx2 or VA-Lip-Runx2 injection exacerbated CCl4 -induced liver fibrosis. In vitro analysis demonstrated that Runx2 promoted HSC activation and proliferation, whereas Runx2 knockdown in HSC suppressed these effects. RNA-seq and Runx2 ChIP-seq analysis demonstrated that Runx2 could promote integrin alpha-V (Itgav) expression by binding to its promoter. Blockade of Itgav attenuated Runx2-induced HSC activation and liver fibrosis. Additionally, we found that cytokines (TGF-β1, PDGF, EGF) promote the expression and nuclear translocation of Runx2 through protein kinase A (PKA) in HSC.
    CONCLUSIONS: Runx2 is critical for HSC activation via transcriptionally regulating Itgav expression during liver fibrosis, and may be a promising therapeutic target for liver fibrosis.
    Keywords:  HSC activation; Itgav; PKA; Runx2; TGF-β1
    DOI:  https://doi.org/10.1002/ctm2.1316
  46. Funct Integr Genomics. 2023 Jul 03. 23(3): 220
    Involvement of IGF1 in endoplasmic reticulum stress contributes to cataract formation through regulating Nrf2/NF-κB signaling.
    Ruiping Peng, Hongmei Lin, Haocheng Zhu, Yi Zhang, Tiancheng Bao, Weili Li, Juan Deng.
      Endoplasmic reticulum (ER) stress is reportedly involved in the development of ophthalmic diseases. This study aimed to investigate the role and potential mechanism of insulin-like growth factor 1 (IGF1) in ER stress. A mouse cataract model was constructed by subcutaneous injection of sodium selenite, and sh-IGF1 was used to evaluate the effect of silencing IGF1 on cataract progression. Slit-lamp and histological examination of the lens were performed to examine lens damage. The regulatory effects of IGF1 on inflammatory responses, oxidative stress, and ER stress were evaluated using ELISA, reverse transcription-quantitative PCR (RT-qPCR), and immunoblotting analysis. Tunicamycin was used to induce ER stress in the lens of epithelial cells. The NF-E2 related factor-2 (Nrf2) inhibitor ML385 and nuclear factor-κB (NF-κB) agonist diprovocim were used to confirm whether IGF1 regulates inflammation and ER stress through Nrf2/NF-κB signaling. Silencing IGF1 alleviated lens damage and reduced lens turbidity in the cataract mice. Silencing IGF1 inhibited inflammatory response, oxidative stress and ER stress response. Meanwhile, IGF1 was highly expressed in sodium selenite-treated lens epithelial cells. The ER stress agonist tunicamycin suppressed cell viability as well as induced ER stress, oxidative stress and inflammation. Silencing IGF1 increased cell viability, EdU-positive rate and migration. Also, silencing of IGF1 reduced inflammation and ER stress via regulating Nrf2/NF-κB pathway. This study reveals silencing IGF1 attenuated cataract through regulating Nrf2/NF-κB signaling, which shares novel insights into the underlying mechanism of cataract and provides potential therapeutic target for cataract.
    Keywords:  Cataract; Endoplasmic reticulum stress; Insulin-like growth factors 1
    DOI:  https://doi.org/10.1007/s10142-023-01152-7
  47. BMB Rep. 2023 Jul 04. pii: 5877. [Epub ahead of print]
    Regulation of glucose and glutamine metabolism to overcome cisplatin resistance in intrahepatic cholangiocarcinoma.
    So Mi Yang, Jueun Kim, Ji-Yeon Lee, Jung-Shin Lee, Ji Min Lee.
      Intrahepatic cholangiocarcinoma (ICC) is one of the bile duct cancers and a rare malignant tumor with a poor prognosis owing to a lack of early diagnosis and resistance to conventional chemotherapy. A combination of gemcitabine and cisplatin is a treatment approach typically being attempted for the first line. However, its underlying mechanism of resistance to chemotherapy is poorly understood. We addressed this by studying the dynamics in the human ICC SCK cell line. Here, we report that the regulation of glucose and glutamine metabolism is a key factor in overcoming cisplatin resistance of SCK. Through RNA sequencing analysis, we discovered that the cell cycle-related gene set exhibits a high enrichment score in cisplatin-resistant SCK (SCK-R) cells rather than parental SCK (SCK WT) cells. Cell cycle progression correlates with increased nutrient requirement and cancer proliferation or metastasis. Commonly, cancer cells are dependent upon glucose and glutamine availability for survival and proliferation. Indeed, we observed increased expression of GLUT (glucose transporter), ASCT2 (glutamine transporter), and cancer progression markers in SCK-R cells. Thus, we inhibited enhanced metabolic reprogramming in SCK-R cells through nutrient starvation. Especially under glucose starvation, SCK-R cells are sensitized to cisplatin. Moreover, glutaminase-1 (GLS1), which is a mitochondrial enzyme involved in tumorigenesis and progression in cancer cells was upregulated in SCK-R cells. Targeting GLS1 with the GLS1 inhibitor CB-839 (telaglenastat) effectively reduced the expression of cancer progression markers. Taken together, our study suggests that a combination of GLUT inhibition, which mimics glucose starvation, and GLS1 inhibition could be a therapeutic strategy to increase the chemosensitivity of ICC.
  48. J Cell Biol. 2023 Sep 04. pii: e202208150. [Epub ahead of print]222(9):
    PTEN is both an activator and a substrate of chaperone-mediated autophagy.
    Katherine K Zhang, Calvin M Burns, Mary E Skinner, David B Lombard, Richard A Miller, S Joseph Endicott.
      PTEN is a crucial negative regulator of the INS/PI3K/AKT pathway and is one of the most commonly mutated tumor suppressors in cancer. Global overexpression (OE) of PTEN in mice shifts metabolism to favor oxidative phosphorylation over glycolysis, reduces fat mass, and extends the lifespan of both sexes. We demonstrate that PTEN regulates chaperone-mediated autophagy (CMA). Using cultured cells and mouse models, we show that PTEN OE enhances CMA, dependent upon PTEN's lipid phosphatase activity and AKT inactivation. Reciprocally, PTEN knockdown reduces CMA, which can be rescued by inhibiting class I PI3K or AKT. Both PTEN and CMA are negative regulators of glycolysis and lipid droplet formation. We show that suppression of glycolysis and lipid droplet formation downstream of PTEN OE depends on CMA activity. Finally, we show that PTEN protein levels are sensitive to CMA and that PTEN accumulates in lysosomes with elevated CMA. Collectively, these data suggest that CMA is both an effector and a regulator of PTEN.
    DOI:  https://doi.org/10.1083/jcb.202208150
  49. Clin Transl Med. 2023 Jul;13(7): e1325
    Mitochondrial general control of amino acid synthesis 5 like 1 promotes nonalcoholic steatohepatitis development through ferroptosis-induced formation of neutrophil extracellular traps.
    Tingting Lv, Xiaofeng Xiong, Wei Yan, Mei Liu, Hongwei Xu, Qin He.
       BACKGROUND: Mitochondria play central roles in metabolic diseases including nonalcoholic steatohepatitis (NASH). However, how mitochondria regulate NASH progression remains largely unknown. Our previous findings demonstrate that mitochondrial general control of amino acid synthesis 5 like 1 (GCN5L1) is associated with mitochondrial metabolism. Nevertheless, the roles of GCN5L1 in NASH are unclear.
    AIMS AND METHODS: The GCN5L1 expression was detected in the fatty livers of NASH patients and animals. Hepatocyte-specific GCN5L1 deficiency or overexpression mice were used to induce NASH models by feeding with a high-fat/high-cholesterol or methionine-choline deficient diet. The molecular mechanisms underlying GCN5L1-regulated NASH were further explored and verified in mice.
    RESULTS AND CONCLUSIONS: GCN5L1 expression was increased in NASH patients. Upregulated GCN5L1 level was also illustrated in NASH mice. Mice with hepatocyte-specific GCN5L1 conditional knockout improved the inflammatory response compared to GCN5L1flox/flox mice. However, overexpression of mitochondrial GCN5L1 augmented the inflammatory response. Mechanically, GCN5L1 acetylated CypD and enhanced its binding with ATP5B, which induced the opening of mitochondrial permeability transition pores and the release of mitochondrial ROS into the cytoplasm. The increased ROS promoted ferroptosis of hepatocytes and induced accumulation of high mobility group box 1 in the microenvironment, which recruited neutrophils and induced the generation of neutrophil extracellular traps (NETs). NETs block impaired GCN5L1-induced NASH progression. Furthermore, the upregulation of GCN5L1 in NASH was contributed by lipid overload-induced endoplasmic reticulum stress. Together, mitochondrial GCN5L1 has a vital function in promoting NASH progression by regulating oxidative metabolism and the hepatic inflammatory microenvironment. Thus, GCN5L1 might be a potential intervention target in NASH treatment.
    Keywords:  GCN5L1; ferroptosis; mitochondrial permeability transition pores; neutrophil extracellular traps; nonalcoholic steatohepatitis
    DOI:  https://doi.org/10.1002/ctm2.1325
  50. Cell Death Dis. 2023 Jul 06. 14(7): 404
    Diacylglycerol lipase alpha promotes hepatocellular carcinoma progression and induces lenvatinib resistance by enhancing YAP activity.
    Yu-Chuan Yan, Guang-Xiao Meng, Chun-Cheng Yang, Ya-Fei Yang, Si-Yu Tan, Lun-Jie Yan, Zi-Niu Ding, Yun-Long Ma, Zhao-Ru Dong, Tao Li.
      As an important hydrolytic enzyme that yields 2-AG and free fatty acids, diacylglycerol lipase alpha (DAGLA) is involved in exacerbating malignant phenotypes and cancer progression, but the role of the DAGLA/2-AG axis in HCC progression remains unclear. Here, we found that the upregulation of components of the DAGLA/2-AG axis in HCC samples is correlated with tumour stage and patient prognosis. In vitro and in vivo experiments demonstrated that the DAGLA/2-AG axis promoted HCC progression by regulating cell proliferation, invasion and metastasis. Mechanistically, the DAGLA/2AG axis significantly inhibited LATS1 and YAP phosphorylation, promoted YAP nuclear translocation and activity, and ultimately led to TEAD2 upregulation and increased PHLDA2 expression, which could be enhanced by DAGLA/2AG-induced activation of the PI3K/AKT pathway. More importantly, DAGLA induced resistance to lenvatinib therapy during HCC treatment. Our study demonstrates that inhibiting the DAGLA/2-AG axis could be a novel therapeutic strategy to inhibit HCC progression and enhance the therapeutic effects of TKIs, which warrant further clinical studies.
    DOI:  https://doi.org/10.1038/s41419-023-05919-5
  51. Biomed Pharmacother. 2023 Jun 29. pii: S0753-3322(23)00864-8. [Epub ahead of print]165 115073
    Estradiol cypionate inhibits proliferation and promotes apoptosis of gastric cancer by regulating AKT ubiquitination.
    Xiaochen Qiu, Juan Wang, Nan Zhang, Tongde Du, Lin Chen, Hongqing Xi.
      Gastric cancer is a common gastrointestinal malignancy worldwide, with a high mortality rate and poor prognosis. Multidrug resistance remains a major obstacle to successful treatment for patients. Hence, it is of great significance to develop novel therapies to potentiate the anti-tumor effect. In this study, we have investigated the effect of estradiol cypionate (ECP) on gastric cancer in vitro and vivo. Our data show that ECP inhibited the proliferation, promoted apoptosis, and caused G1/S phase arrest of gastric cancer cells. The mechanism by which ECP promoted apoptosis of gastric cancer cells was related to the downregulation of AKT protein expression caused by the increased ubiquitination modification levels of AKT, which finally inhibited the over-activation of the PI3K-AKT-mTOR signaling pathway. In vivo tumorigenesis experiments showed that ECP significantly inhibited the growth of gastric cancer cells, showing promise for clinical application. The above findings indicate that ECP inhibited the growth of gastric cancer and induced apoptosis through the PI3K /Akt/mTOR pathway. In summary, the efficacy showed in our data suggests that ECP is a promising anti-tumor compound for gastric cancer.
    Keywords:  AKT; Apoptosis; Estradiol cypionate; Gastric cancer; Proliferation
    DOI:  https://doi.org/10.1016/j.biopha.2023.115073
  52. bioRxiv. 2023 Jun 02. pii: 2023.05.29.541816. [Epub ahead of print]
    A zebrafish xenotransplant model of anaplastic thyroid cancer to study the tumor microenvironment and innate immune cell interactions in vivo.
    Cassia Michael, Antonio Di Cristofano, Sofia de Oliveira.
      Anaplastic thyroid cancer (ATC) is a rare malignant subtype of thyroid cancer. While ATC is rare it accounts for a disproportionately high number of thyroid cancer-related deaths. Here we developed an ATC xenotransplant model in zebrafish larvae, where we can study tumorigenesis and therapeutic response in vivo. Using both mouse (T4888M) and human (C643) derived fluorescently labeled ATC cell lines we show these cell lines display different engraftment rates, mass volume, proliferation, and angiogenic potential. Next, using a PIP-FUCCI reporter to track proliferation in-vivo we observed cells in each phase of the cell cycle. Additionally, we performed long-term non-invasive intravital microscopy over 48 hours to understand cellular dynamics in the tumor microenvironment at the single cell level. Lastly, we tested a well-known mTOR inhibitor to show our model could be used as an effective screening platform for new therapeutic compounds. Altogether, we show that zebrafish xenotransplants make a great model to study thyroid carcinogenesis and the tumor microenvironment, while also being a suitable model to test new therapeutics in vivo .
    SUMMARY STATEMENT: Anaplastic thyroid cancer xenotransplant model in zebrafish larvae to study thyroid cancer tumorigenesis and tumor microenvironment. Using confocal microscopy to understand cell cycle progression, interactions with the innate immune system, and test therapeutic compounds in vivo.
    DOI:  https://doi.org/10.1101/2023.05.29.541816
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