bims-rimeca 2022-07-17 papers

Cell Death Discov. 2022 Jul 15. 8(1): 322

N6-methyladenosine (m6A) methyltransferase METTL3 regulates sepsis-induced myocardial injury through IGF2BP1/HDAC4 dependent manner.

Hao Shen, Keliang Xie, Miaomiao Li, Qianyu Yang, Xiaoye Wang.

Recent studies have identified that N6-methyladenosine (m6A) extensively participates in the myocardial injury pathophysiological process. However, the role of m6A on sepsis-induced myocardial injury is still unclear. Here, we investigated the functions and mechanism of m6A methyltransferase METTL3 for septic myocardial injury. Results illustrated that the m6A modification level and METTL3 up-regulated in the lipopolysaccharide (LPS)-induced cardiomyocytes (H9C2 cells). Methylated RNA immunoprecipitation sequencing (MeRIP-Seq) revealed the m6A profile of the septic myocardial injury cellular model. Functionally, METTL3 knockdown repressed the inflammatory damage of cardiomyocytes induced by LPS. Mechanistically, we found that HDAC4 had remarkable m6A modification sites on its 3'-UTR genome, acting as the downstream target of METTL3. Besides, m6A reader IGF2BP1 recognized the m6A modification sites on HDAC4 mRNA and enhanced its RNA stability. In conclusion, the findings illustrated a role of METTL3/IGF2BP1/m6A/HDAC4 axis on sepsis-induced myocardial injury, which might provide novel therapeutic strategy for septic myocardial injury.

DOI: https://doi.org/10.1038/s41420-022-01099-x

EBioMedicine. 2022 Jul 07. pii: S2352-3964(22)00323-1. [Epub ahead of print]82 104142

METTL14-mediated epitranscriptome modification of MN1 mRNA promote tumorigenicity and all-trans-retinoic acid resistance in osteosarcoma.

Hong-Bo Li, Gang Huang, Jian Tu, Dong-Ming Lv, Qing-Lin Jin, Jun-Kai Chen, Yu-Tong Zou, Dung-Fang Lee, Jing-Nan Shen, Xian-Biao Xie.

BACKGROUND: Osteosarcoma (OS) is the most common primary malignant bone tumor in adolescents. The molecular mechanism behind OS progression and metastasis remains poorly understood, which limits the effectiveness of current therapies. RNA N6-methyladenosine (m6A) modification plays a critical role in influencing RNA fate. However, the biological significance of m6A modification and its potential regulatory mechanisms in the development of OS remain unclear.
METHODS: Liquid chromatography-tandem mass spectrometry (LC-MS/MS), dot blotting, and colorimetric ELISA were used to detect m6A levels. Western blotting, quantitative real-time PCR (RT-qPCR) and immunohistochemistry (IHC) were used to investigate METTL14 expression levels. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and transcriptomic RNA sequencing (RNA-seq) were used to screen the target genes of METTL14. RNA pull-down and RNA immunoprecipitation (RIP) assays were conducted to explore the specific binding of target genes and relevant m6A "readers". RNA stability and polysome analysis assays were used to detect the half-lives and translation efficiencies of the downstream genes of METTL14. IHC and clinical data were applied to explore the clinical correlations of METTL14 and its downstream target genes with the prognosis of OS.
FINDINGS: We observed the abundance of m6A modifications in OS and revealed that METTL14 plays an oncogenic role in facilitating OS progression. MeRIP-seq and RNA-seq revealed that MN1 is a downstream gene of METTL14. MN1 contributes to tumor progression and all-trans-retinoic acid (ATRA) chemotherapy resistance in OS. Mechanistically, MN1 is methylated by METTL14, specifically in the coding sequence (CDS) regions, and this modification is recognized by the specific m6A reader insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) to prevent MN1 mRNA degradation and promote it translation efficiency. IHC showed that MN1 expression was positively correlated with METTL14 and IGF2BP2 expression in OS tissues. The METTL14-IGF2BP2-MN1 panel demonstrated more promising prognostic value for OS patients than any of these molecules individually.
INTERPRETATION: Our study revealed that METTL14 contributes to OS progression and ATRA resistance as an m6A RNA methylase by regulating the stability and translation efficiency of MN1 and thus provides both an underlying biomarker panel for prognosis prediction in OS patients.
FUNDING: This work was supported by the National Natural Science Foundation of China (Grants 81972510 and 81772864).

Keywords: Lung metastasis; METTL14; Osteosarcoma; m(6)A modification

DOI: https://doi.org/10.1016/j.ebiom.2022.104142

Cell Mol Biol (Noisy-le-grand). 2022 May 22. 68(1): 130-139

The prognostic value of N6-methyladenosine RBM15 regulators in lung adenocarcinoma.

Mingsheng Ma, Wei Wang, Biying Wang, Yichen Yang, Yunchao Huang, Guangqiang Zhao, Lianhua Ye.

N6-methyladenosine (m6A) is the most common internal modification in mammalian mRNAs while RNA-binding motif protein 15 (RBM15) is an important methyltransferase in m6A modification. Increasing evidences have shown that RBM15 has a close correlation with lung cancer. However, specific functions of RBM15 in lung adenocarcinoma (LUAD) are limited. RBM15 expression was analyzed in human LUAD tissues and matched healthy lung tissue. RBM15 was knocked down via siRNA in A549 and H1734 cells. The relationships between RBM15 with cellular functions characteristics and mRNA m6A levels were explored. We performed functional characterization in A549 and H1734 cells lines to elucidate the molecular role of RBM15. Results found that RBM15 was up-regulated in the LUAD tissue and cells, which was linked to poor survival of LUAD patients. RBM15 can be knocked down via siRNA in A549, which leads to the exploration of the associations between RBM15 with cell characteristics. In vivo, RBM15 knockdown could decrease the methylation level, reduce proliferation, accelerate apoptosis and inhibit tumor growth. Our research shows that RBM15 facilitates LUAC cell progression by m6A demethylation. However, it is necessary to conduct further researches on potential downstream molecular mechanisms and m6A modification of RBM15 activity in LUAC.

DOI: https://doi.org/10.14715/cmb/2022.68.1.17

Cell Signal. 2022 Jul 12. pii: S0898-6568(22)00168-1. [Epub ahead of print] 110406

FTO-dependent N(6)-Methyladenosine regulates the progression of endometriosis via the ATG5/PKM2 Axis.

Han Wang, Zongwen Liang, Yanling Gou, Zhi Li, Yingying Cao, Na Jiao, Jiahuan Tan, Yangyang Yu, Zongfeng Zhang.

N6-methyladenosine (m6A), the most abundant internal modification on mRNAs in eukaryotes, plays a role in endometriosis (EMs). However, the underlying mechanism remains largely unclear. Here, we found that FTO is downregulated in EMs; and plays an important role in regulating glycolysis, proliferation, and metastasis of ectopic endometriotic stromal cells (EESCs) by targeting ATG5. We demonstrated that FTO promotes ATG5 expression in a m6A-dependent manner, and further studies revealed that PKM2 is a target of ATG5. Upon FTO overexpression, increased ATG5 protein expression at low m6A levels inhibited the expression of PKM2, thereby reducing the glycolysis level of EESCs. In addition, we demonstrated through in vitro functional experiments that FTO regulates glycolysis, proliferation, and metastasis of EESCs through the ATG5/PKM2 axis. In conclusion, these findings reveal the functional importance of the m6A methylation mechanism of FTO in regulating the development of EMs, which expands our understanding of this interaction, which is crucial for the development of therapeutic strategies for EMs.

Keywords: Autophagy; Endometriosis; FTO; Glycolysis; m6A methylation

DOI: https://doi.org/10.1016/j.cellsig.2022.110406

Phytomedicine. 2022 Jun 27. pii: S0944-7113(22)00378-6. [Epub ahead of print]104 154299

Isoliquiritigenin inhibits non-small cell lung cancer progression via m6A/IGF2BP3-dependent TWIST1 mRNA stabilization.

Yameng Cui, Yulin Wu, Cong Wang, Zuolin Wang, Yanyang Li, Zhansheng Jiang, Wei Zhao, Zhanyu Pan.

BACKGROUND: N6-methyladenosine (m6A) has been identified to regulate the tumorigenesis and development of various tumors, including non-small cell lung cancer (NSCLC). Isoliquiritigenin (ISL), derived from the Chinese herb licorice, shows a significant anti-tumor activity on multiple human cancers. However, the role of ISL on NSCLC through m6A is still unclear.
PURPOSE: Here, we investigated the anti-tumor effect of ISL on NSCLC, and explored whether ISL affected the NSCLC phenotype by modulating its m6A modification.
METHODS: Cell proliferation, migration and invasion assays were performed to evaluate the inhibitory effects of ISL on NSCLC cells. M6A enrichment was determined by m6A quantitative analysis. The mechanism regarding IGF2BP3 was explored using RIP-PCR, MeRIP-qPCR and RNA decay analysis.
RESULTS: ISL significantly repressed the proliferation, migration and invasion of NSCLC cells in vitro. In addition, m6A reader IGF2BP3 expression significantly increased in NSCLC tissues compared to adjacent tissues, and was positively correlated with NSCLC patients' poor survival. Mechanistically, ISL reduced m6A modification and down-regulated IGF2BP3 expression in NSCLC. Furthermore, IGF2BP3 enhanced the mRNA stability of twist family bHLH transcription factor 1 (TWIST1) in m6A-dependent manner. Moreover, ISL treatment combined with TWSIT1 knockdown effectively reversed IGF2BP3 overexpression-induced NSCLC cells' proliferation, migration and invasion.
CONCLUSION: Our findings uncover that ISL might function as an anticarcinogen through targeting IGF2BP3/m6A/TWIST1 axis for NSCLC.

Keywords: IGF2BP3; Isoliquiritigenin; Non-small cell lung cancer; TWIST1; m(6)A

DOI: https://doi.org/10.1016/j.phymed.2022.154299