bims-instec Biomed News
on Intestinal stem cells and chemoresistance in colon cancer and intestinal regeneration
Issue of 2024‒06‒09
sixteen papers selected by
Maria-Virginia Giolito, Université Catholique de Louvain
  1. Redefining intestinal stemness: The emergence of a new ISC population.
  2. Isthmus progenitor cells contribute to homeostatic cellular turnover and support regeneration following intestinal injury.
  3. Protein arginine methyltransferase 1 regulates mouse enteroendocrine cell development and homeostasis.
  4. Time-resolved fate mapping identifies the intestinal upper crypt zone as an origin of Lgr5+ crypt base columnar cells.
  5. Azoxymethane-induced carcinogenesis-like model of mouse intestine and mouse embryonic stem cell-derived intestinal organoids.
  6. Defining the KRAS- and ERK-dependent transcriptome in KRAS-mutant cancers.
  7. Merging Metabolic Modeling and Imaging for Screening Therapeutic Targets in Colorectal Cancer.
  8. Integrated analysis reveals a novel 5-fluorouracil resistance-based prognostic signature with promising implications for predicting the efficacy of chemotherapy and immunotherapy in patients with colorectal cancer.
  9. The manganese transporter SLC39A8 links alkaline ceramidase 1 to inflammatory bowel disease.
  10. A developmental constraint model of cancer cell states and tumor heterogeneity.
  11. Patient tissue-derived FGFR4-variant and wild-type colorectal cancer organoid development and anticancer drug sensitivity testing.
  12. Inactivation of KDM6A promotes the progression of colorectal cancer by enhancing the glycolysis.
  13. GOLPH3 inhibits erastin-induced ferroptosis in colorectal cancer cells.
  14. KRAS G12C Inhibitors in the Treatment of Metastatic Colorectal Cancer.
  15. PDP1 promotes KRAS mutant colorectal cancer progression by serving as a scaffold for BRAF and MEK1.
  16. Zebrafish Avatar-test forecasts clinical response to chemotherapy in patients with colorectal cancer.
  1. Cell. 2024 Jun 06. pii: S0092-8674(24)00446-X. [Epub ahead of print]187(12): 2900-2902
    Redefining intestinal stemness: The emergence of a new ISC population.
    Mei-Lan Li, Kaelyn Sumigray.
      In tissue homeostasis, intestinal stem cells (ISCs) undergo continuous self-renewal to sustain rapid cellular turnover. In this issue of Cell, Capdevila et al.1 and Malagola, Vasciaveo, et al.2 identify a new ISC population in the upper crypt that can generate Lgr5+ stem cells during homeostasis.
    DOI:  https://doi.org/10.1016/j.cell.2024.04.021
  2. Cell. 2024 Jun 06. pii: S0092-8674(24)00490-2. [Epub ahead of print]187(12): 3056-3071.e17
    Isthmus progenitor cells contribute to homeostatic cellular turnover and support regeneration following intestinal injury.
    Ermanno Malagola, Alessandro Vasciaveo, Yosuke Ochiai, Woosook Kim, Biyun Zheng, Luca Zanella, Alexander L E Wang, Moritz Middelhoff, Henrik Nienhüser, Lu Deng, Feijing Wu, Quin T Waterbury, Bryana Belin, Jonathan LaBella, Leah B Zamechek, Melissa H Wong, Linheng Li, Chandan Guha, Chia-Wei Cheng, Kelley S Yan, Andrea Califano, Timothy C Wang.
      The currently accepted intestinal epithelial cell organization model proposes that Lgr5+ crypt-base columnar (CBC) cells represent the sole intestinal stem cell (ISC) compartment. However, previous studies have indicated that Lgr5+ cells are dispensable for intestinal regeneration, leading to two major hypotheses: one favoring the presence of a quiescent reserve ISC and the other calling for differentiated cell plasticity. To investigate these possibilities, we studied crypt epithelial cells in an unbiased fashion via high-resolution single-cell profiling. These studies, combined with in vivo lineage tracing, show that Lgr5 is not a specific ISC marker and that stemness potential exists beyond the crypt base and resides in the isthmus region, where undifferentiated cells participate in intestinal homeostasis and regeneration following irradiation (IR) injury. Our results provide an alternative model of intestinal epithelial cell organization, suggesting that stemness potential is not restricted to CBC cells, and neither de-differentiation nor reserve ISC are drivers of intestinal regeneration.
    Keywords:  adult stem cells; cell potency; epithelial stem cells; intestinal stem cells; intestine; plasticity; regeneration; regulatory network analysis; single cell; stemness signature
    DOI:  https://doi.org/10.1016/j.cell.2024.05.004
  3. Cell Biosci. 2024 Jun 04. 14(1): 70
    Protein arginine methyltransferase 1 regulates mouse enteroendocrine cell development and homeostasis.
    Zhaoyi Peng, Lingyu Bao, James Iben, Shouhong Wang, Bingyin Shi, Yun-Bo Shi.
      BACKGROUND: The adult intestinal epithelium is a complex, self-renewing tissue composed of specialized cell types with diverse functions. Intestinal stem cells (ISCs) located at the bottom of crypts, where they divide to either self-renew, or move to the transit amplifying zone to divide and differentiate into absorptive and secretory cells as they move along the crypt-villus axis. Enteroendocrine cells (EECs), one type of secretory cells, are the most abundant hormone-producing cells in mammals and involved in the control of energy homeostasis. However, regulation of EEC development and homeostasis is still unclear or controversial. We have previously shown that protein arginine methyltransferase (PRMT) 1, a histone methyltransferase and transcription co-activator, is important for adult intestinal epithelial homeostasis.RESULTS: To investigate how PRMT1 affects adult intestinal epithelial homeostasis, we performed RNA-Seq on small intestinal crypts of tamoxifen-induced intestinal epithelium-specific PRMT1 knockout and PRMT1fl/fl adult mice. We found that PRMT1fl/fl and PRMT1-deficient small intestinal crypts exhibited markedly different mRNA profiles. Surprisingly, GO terms and KEGG pathway analyses showed that the topmost significantly enriched pathways among the genes upregulated in PRMT1 knockout crypts were associated with EECs. In particular, genes encoding enteroendocrine-specific hormones and transcription factors were upregulated in PRMT1-deficient small intestine. Moreover, a marked increase in the number of EECs was found in the PRMT1 knockout small intestine. Concomitantly, Neurogenin 3-positive enteroendocrine progenitor cells was also increased in the small intestinal crypts of the knockout mice, accompanied by the upregulation of the expression levels of downstream targets of Neurogenin 3, including Neuod1, Pax4, Insm1, in PRMT1-deficient crypts.
    CONCLUSIONS: Our finding for the first time revealed that the epigenetic enzyme PRMT1 controls mouse enteroendocrine cell development, most likely via inhibition of Neurogenin 3-mediated commitment to EEC lineage. It further suggests a potential role of PRMT1 as a critical transcriptional cofactor in EECs specification and homeostasis to affect metabolism and metabolic diseases.
    Keywords:  Differentiation; Enteroendocrine cell; Methyltransferase; Neurogenin 3; RNA-Seq; Transcription
    DOI:  https://doi.org/10.1186/s13578-024-01257-x
  4. Cell. 2024 Jun 06. pii: S0092-8674(24)00491-4. [Epub ahead of print]187(12): 3039-3055.e14
    Time-resolved fate mapping identifies the intestinal upper crypt zone as an origin of Lgr5+ crypt base columnar cells.
    Claudia Capdevila, Jonathan Miller, Liang Cheng, Adam Kornberg, Joel J George, Hyeonjeong Lee, Theo Botella, Christine S Moon, John W Murray, Stephanie Lam, Ruben I Calderon, Ermanno Malagola, Gary Whelan, Chyuan-Sheng Lin, Arnold Han, Timothy C Wang, Peter A Sims, Kelley S Yan.
      In the prevailing model, Lgr5+ cells are the only intestinal stem cells (ISCs) that sustain homeostatic epithelial regeneration by upward migration of progeny through elusive upper crypt transit-amplifying (TA) intermediates. Here, we identify a proliferative upper crypt population marked by Fgfbp1, in the location of putative TA cells, that is transcriptionally distinct from Lgr5+ cells. Using a kinetic reporter for time-resolved fate mapping and Fgfbp1-CreERT2 lineage tracing, we establish that Fgfbp1+ cells are multi-potent and give rise to Lgr5+ cells, consistent with their ISC function. Fgfbp1+ cells also sustain epithelial regeneration following Lgr5+ cell depletion. We demonstrate that FGFBP1, produced by the upper crypt cells, is an essential factor for crypt proliferation and epithelial homeostasis. Our findings support a model in which tissue regeneration originates from upper crypt Fgfbp1+ cells that generate progeny propagating bi-directionally along the crypt-villus axis and serve as a source of Lgr5+ cells in the crypt base.
    Keywords:  Fgfbp1; Lgr5; crypt base columnar cells; intestinal epithelium; intestinal stem cells; intestinal upper crypt; lineage hierarchy; time-resolved fate mapping; tissue regeneration; transit-amplifying cells
    DOI:  https://doi.org/10.1016/j.cell.2024.05.001
  5. Mol Biol Rep. 2024 Jun 01. 51(1): 704
    Azoxymethane-induced carcinogenesis-like model of mouse intestine and mouse embryonic stem cell-derived intestinal organoids.
    Hatice Burcu Şişli, Selinay Şenkal Turhan, Ezgi Bulut Okumuş, Özüm Begüm Böke, Özüm Erdoğmuş, Berke Kül, Engin Sümer, Ayşegül Doğan.
      BACKGROUND: Tumor modeling using organoids holds potential in studies of cancer development, enlightening both the intracellular and extracellular molecular mechanisms behind different cancer types, biobanking, and drug screening. Intestinal organoids can be generated in vitro using a unique type of adult stem cells which are found at the base of crypts and are characterized by their high Lgr5 expression levels.METHODS AND RESULTS: In this study, we successfully established intestinal cancer organoid models by using both the BALB/c derived and mouse embryonic stem cells (mESCs)-derived intestinal organoids. In both cases, carcinogenesis-like model was developed by using azoxymethane (AOM) treatment. Carcinogenesis-like model was verified by H&E staining, immunostaining, relative mRNA expression analysis, and LC/MS analysis. The morphologic analysis demonstrated that the number of generated organoids, the number of crypts, and the intensity of the organoids were significantly augmented in AOM-treated intestinal organoids compared to non-AOM-treated ones. Relative mRNA expression data revealed that there was a significant increase in both Wnt signaling pathway-related genes and pluripotency transcription factors in the AOM-induced intestinal organoids.
    CONCLUSION: We successfully developed simple carcinogenesis-like models using mESC-based and Lgr5 + stem cell-based intestinal organoids. Intestinal organoid based carcinogenesi models might be used for personalized cancer therapy in the future.
    Keywords:  AOM; Cancer; Intestinal organoids; Lgr5; Organoid; Pluripotency
    DOI:  https://doi.org/10.1007/s11033-024-09660-w
  6. Science. 2024 Jun 07. 384(6700): eadk0775
    Defining the KRAS- and ERK-dependent transcriptome in KRAS-mutant cancers.
    Jeffrey A Klomp, Jennifer E Klomp, Clint A Stalnecker, Kirsten L Bryant, A Cole Edwards, Kristina Drizyte-Miller, Priya S Hibshman, J Nathaniel Diehl, Ye S Lee, Alexis J Morales, Khalilah E Taylor, Sen Peng, Nhan L Tran, Laura E Herring, Alex W Prevatte, Natalie K Barker, Laura D Hover, Jill Hallin, Saikat Chowdhury, Oluwadara Coker, Hey Min Lee, Craig M Goodwin, Prson Gautam, Peter Olson, James G Christensen, John P Shen, Scott Kopetz, Lee M Graves, Kian-Huat Lim, Andrea Wang-Gillam, Krister Wennerberg, Adrienne D Cox, Channing J Der.
      How the KRAS oncogene drives cancer growth remains poorly understood. Therefore, we established a systemwide portrait of KRAS- and extracellular signal-regulated kinase (ERK)-dependent gene transcription in KRAS-mutant cancer to delineate the molecular mechanisms of growth and of inhibitor resistance. Unexpectedly, our KRAS-dependent gene signature diverges substantially from the frequently cited Hallmark KRAS signaling gene signature, is driven predominantly through the ERK mitogen-activated protein kinase (MAPK) cascade, and accurately reflects KRAS- and ERK-regulated gene transcription in KRAS-mutant cancer patients. Integration with our ERK-regulated phospho- and total proteome highlights ERK deregulation of the anaphase promoting complex/cyclosome (APC/C) and other components of the cell cycle machinery as key processes that drive pancreatic ductal adenocarcinoma (PDAC) growth. Our findings elucidate mechanistically the critical role of ERK in driving KRAS-mutant tumor growth and in resistance to KRAS-ERK MAPK targeted therapies.
    DOI:  https://doi.org/10.1126/science.adk0775
  7. bioRxiv. 2024 May 25. pii: 2024.05.24.595756. [Epub ahead of print]
    Merging Metabolic Modeling and Imaging for Screening Therapeutic Targets in Colorectal Cancer.
    Niki Tavakoli, Emma J Fong, Abigail Coleman, Yu-Kai Huang, Mathias Bigger, Michael E Doche, Seungil Kim, Heinz-Josef Lenz, Nicholas A Graham, Paul Macklin, Stacey D Finley, Shannon M Mumenthaler.
      Cancer-associated fibroblasts (CAFs) play a key role in metabolic reprogramming and are well-established contributors to drug resistance in colorectal cancer (CRC). To exploit this metabolic crosstalk, we integrated a systems biology approach that identified key metabolic targets in a data-driven method and validated them experimentally. This process involved high-throughput computational screening to investigate the effects of enzyme perturbations predicted by a computational model of CRC metabolism to understand system-wide effects efficiently. Our results highlighted hexokinase (HK) as one of the crucial targets, which subsequently became our focus for experimental validation using patient-derived tumor organoids (PDTOs). Through metabolic imaging and viability assays, we found that PDTOs cultured in CAF conditioned media exhibited increased sensitivity to HK inhibition. Our approach emphasizes the critical role of integrating computational and experimental techniques in exploring and exploiting CRC-CAF crosstalk.
    DOI:  https://doi.org/10.1101/2024.05.24.595756
  8. Apoptosis. 2024 Jun 02.
    Integrated analysis reveals a novel 5-fluorouracil resistance-based prognostic signature with promising implications for predicting the efficacy of chemotherapy and immunotherapy in patients with colorectal cancer.
    Yufang Hou, Fang Zhang, Jinbao Zong, Tiegang Li, Wenqiang Gan, Silin Lv, Zheng Yan, Zifan Zeng, Liu Yang, Mingxuan Zhou, Wenyi Zhao, Min Yang.
      BACKGROUND: 5-Fluorouracil (5-FU) has been used as a standard first-line treatment for colorectal cancer (CRC) patients. Although 5-FU-based chemotherapy and immune checkpoint blockade (ICB) have achieved success in treating CRC, drug resistance and low response rates remain substantial limitations. Thus, it is necessary to construct a 5-FU resistance-related signature (5-FRSig) to predict patient prognosis and identify ideal patients for chemotherapy and immunotherapy.METHODS: Using bulk and single-cell RNA sequencing data, we established and validated a novel 5-FRSig model using stepwise regression and multiple CRC cohorts and evaluated its associations with the prognosis, clinical features, immune status, immunotherapy, neoadjuvant therapy, and drug sensitivity of CRC patients through various bioinformatics algorithms. Unsupervised consensus clustering was performed to categorize the 5-FU resistance-related molecular subtypes of CRC. The expression levels of 5-FRSig, immune checkpoints, and immunoregulators were determined using quantitative real-time polymerase chain reaction (RT‒qPCR). Potential small-molecule agents were identified via Connectivity Map (CMap) and molecular docking.
    RESULTS: The 5-FRSig and cluster were confirmed as independent prognostic factors in CRC, as patients in the low-risk group and Cluster 1 had a better prognosis. Notably, 5-FRSig was significantly associated with 5-FU sensitivity, chemotherapy response, immune cell infiltration, immunoreactivity phenotype, immunotherapy efficiency, and drug selection. We predicted 10 potential compounds that bind to the core targets of 5-FRSig with the highest affinity.
    CONCLUSION: We developed a valid 5-FRSig to predict the prognosis, chemotherapeutic response, and immune status of CRC patients, thus optimizing the therapeutic benefits of chemotherapy combined with immunotherapy, which can facilitate the development of personalized treatments and novel molecular targeted therapies for patients with CRC.
    Keywords:  5-fluorouracil; Chemotherapy; Colorectal cancer; Immunotherapy; Prognostic signature; Tumor microenvironment
    DOI:  https://doi.org/10.1007/s10495-024-01981-2
  9. Nat Commun. 2024 Jun 05. 15(1): 4775
    The manganese transporter SLC39A8 links alkaline ceramidase 1 to inflammatory bowel disease.
    Eun-Kyung Choi, Thekkelnaycke M Rajendiran, Tanu Soni, Jin-Ho Park, Luisa Aring, Chithra K Muraleedharan, Vicky Garcia-Hernandez, Nobuhiko Kamada, Linda C Samuelson, Asma Nusrat, Shigeki Iwase, Young Ah Seo.
      The metal ion transporter SLC39A8 is associated with physiological traits and diseases, including blood manganese (Mn) levels and inflammatory bowel diseases (IBD). The mechanisms by which SLC39A8 controls Mn homeostasis and epithelial integrity remain elusive. Here, we generate Slc39a8 intestinal epithelial cell-specific-knockout (Slc39a8-IEC KO) mice, which display markedly decreased Mn levels in blood and most organs. Radiotracer studies reveal impaired intestinal absorption of dietary Mn in Slc39a8-IEC KO mice. SLC39A8 is localized to the apical membrane and mediates 54Mn uptake in intestinal organoid monolayer cultures. Unbiased transcriptomic analysis identifies alkaline ceramidase 1 (ACER1), a key enzyme in sphingolipid metabolism, as a potential therapeutic target for SLC39A8-associated IBDs. Importantly, treatment with an ACER1 inhibitor attenuates colitis in Slc39a8-IEC KO mice by remedying barrier dysfunction. Our results highlight the essential roles of SLC39A8 in intestinal Mn absorption and epithelial integrity and offer a therapeutic target for IBD associated with impaired Mn homeostasis.
    DOI:  https://doi.org/10.1038/s41467-024-49049-8
  10. Cell. 2024 Jun 06. pii: S0092-8674(24)00458-6. [Epub ahead of print]187(12): 2907-2918
    A developmental constraint model of cancer cell states and tumor heterogeneity.
    Ayushi S Patel, Itai Yanai.
      Cancer is a disease that stems from a fundamental liability inherent to multicellular life forms in which an individual cell is capable of reneging on the interests of the collective organism. Although cancer is commonly described as an evolutionary process, a less appreciated aspect of tumorigenesis may be the constraints imposed by the organism's developmental programs. Recent work from single-cell transcriptomic analyses across a range of cancer types has revealed the recurrence, plasticity, and co-option of distinct cellular states among cancer cell populations. Here, we note that across diverse cancer types, the observed cell states are proximate within the developmental hierarchy of the cell of origin. We thus posit a model by which cancer cell states are directly constrained by the organism's "developmental map." According to this model, a population of cancer cells traverses the developmental map, thereby generating a heterogeneous set of states whose interactions underpin emergent tumor behavior.
    Keywords:  cancer cell states; cellular plasticity; developmental constraints; tumor heterogeneity; tumorigenesis
    DOI:  https://doi.org/10.1016/j.cell.2024.04.032
  11. Heliyon. 2024 May 30. 10(10): e30985
    Patient tissue-derived FGFR4-variant and wild-type colorectal cancer organoid development and anticancer drug sensitivity testing.
    Hailing Lin, Hongbo Fu, Shishen Sun, Hao Yin, Jie Yuan, Jilin Liao.
      Objectives: FGFR4-variant and wild-type colorectal cancer (CRC) organoids were developed to investigate the effects of FGFR4-targeted drugs, including FGFR4-IN and erdafitinib, on CRC and their possible molecular mechanism.Methods: Clinical CRC tissues were collected, seven CRC organoids were developed, and whole exome sequencing (WES) was performed. CRC organoids were cultured and organoid drug sensitivity studies were conducted. Finally, an FGFR4-variant (no wild-type) CRC patient-derived orthotopic xenograft mouse model was developed. Western blot measured ERK/AKT/STAT3 pathway-related protein levels.
    Results: WES results revealed the presence of FGFR4-variants in 5 of the 7 CRC organoids. The structural organization and integrity of organoids were significantly altered under the influence of targeted drugs (FGFR4-IN-1 and erdafitinib). The effects of FGFR4 targeted drugs were not selective for FGFR4 genotypes. FGFR4-IN-1 and erdafitinib significantly reduced the growth, diameter, and Adenosine Triphosphate (ATP) activity of organoids. Furthermore, chemotherapeutic drugs, including 5-fluorouracil and cisplatin, inhibited FGFR4-variant and wild-type CRC organoid activity. Moreover, the tumor volume of mice was significantly reduced at week 6, and p-ERK1/2, p-AKT, and p-STAT3 levels were down-regulated following FGFR4-IN-1 and erdafitinib treatment.
    Conclusions: FGFR4-targeted and chemotherapeutic drugs inhibited the activity of FGFR4-variant and wild-type CRC organoids, and targeted drugs were more effective than chemotherapeutic drugs at the same concentration. Additionally, FGFR4 inhibitors hindered tumorigenesis in FGFR4-variant CRC organoids through ERK1/2, AKT, and STAT3 pathways. However, no wild-type control was tested in this experiment, which need further confirmation in the next study.
    Keywords:  Colorectal cancer; Drug sensitivity; FGFR4; Organoids
    DOI:  https://doi.org/10.1016/j.heliyon.2024.e30985
  12. Eur J Med Res. 2024 Jun 06. 29(1): 310
    Inactivation of KDM6A promotes the progression of colorectal cancer by enhancing the glycolysis.
    Dexiang Zhang, Xiaohong Zhao, Yu Gao, Meixing Wang, Mi Xiao, Kaihua Zhu, Wei Niu, Yuedi Dai.
      KDM6A (lysine demethylase 6A) has been reported to undergo inactivating mutations in colorectal cancer, but its function in the progression of colorectal cancer has not been evaluated using animal models of colorectal cancer. In this study, we found that knocking out KDM6A expression in mouse intestinal epithelium increased the length of villus and crypt, promoting the development of AOM (azoxymethane)/DSS (dextran sulfate sodium salt)-induced colorectal cancer. On the other hand, knocking down KDM6A expression promoted the growth of colorectal cancer cells. In molecular mechanism studies, we found that KDM6A interacts with HIF-1α; knocking down KDM6A promotes the binding of HIF-1α to the LDHA promoter, thereby promoting LDHA expression and lactate production, enhancing glycolysis. Knocking down LDHA reversed the malignant phenotype caused by KDM6A expression loss. In summary, this study using animal models revealed that KDM6A loss promotes the progression of colorectal cancer through reprogramming the metabolism of the colorectal cancer cells, suggesting that restoring the function of KDM6A is likely to be one of the strategies for colorectal cancer treatment.
    Keywords:  Cancer metabolism; Colorectal cancer; KDM6A; LDHA
    DOI:  https://doi.org/10.1186/s40001-024-01828-1
  13. Cell Biol Int. 2024 Jun 02.
    GOLPH3 inhibits erastin-induced ferroptosis in colorectal cancer cells.
    Lihua Chen, Chunxiao Wang, Xiaojing Chen, Yuze Wu, Mingliang Chen, Xian Deng, Chengzhi Qiu.
      Ferroptosis is a novel form of programmed cell death and is considered to be a druggable target for colorectal cancer (CRC) therapy. However, the role of ferroptosis in CRC and its underlying mechanism are not fully understood. In the present study we found that a protein enriched in the Golgi apparatus, Golgi phosphoprotein 3 (GOLPH3), was overexpressed in human CRC tissue and in several CRC cell lines. The expression of GOLPH3 was significantly correlated with the expression of ferroptosis-related genes in CRC. The overexpression of GOLPH3 in Erastin-induced Caco-2 CRC cells reduced ferroptotic phenotypes, whereas the knockdown of GOLPH3 potentiated ferroptosis in HT-29 CRC cells. GOLPH3 induced the expression of prohibitin-1 (PHB1) and prohibitin-2 (PHB2), which also inhibited ferroptosis in Erastin-treated CRC cells. Moreover, GOLPH3 interacted with PHB2 and nuclear factor erythroid 2-related factor 2 (NRF2) in Caco-2 cells. These observations indicate that GOLPH3 is a negative regulator of ferroptosis in CRC cells. GOLPH3 protects these cells from ferroptosis by inducing the expression of PHB1 and PHB2, and by interacting with PHB2 and NRF2.
    Keywords:  GOLPH3; NRF2; PHB1; PHB2; colorectal cancer; ferroptosis
    DOI:  https://doi.org/10.1002/cbin.12190
  14. Clin Colorectal Cancer. 2024 May 13. pii: S1533-0028(24)00034-3. [Epub ahead of print]
    KRAS G12C Inhibitors in the Treatment of Metastatic Colorectal Cancer.
    Annie Xiao, Marwan Fakih.
      KRAS mutations contribute substantially to the overall colorectal cancer burden and have long been a focus of drug development efforts. After a lengthy preclinical road, KRAS inhibition via the G12C allele has finally become a therapeutic reality. Unlike in NSCLC, early studies of KRAS inhibitors in CRC struggled to demonstrate single agent activity. Investigation into these tissue-specific treatment differences has led to a deeper understanding of the complexities of MAPK signaling and the diverse adaptive feedback responses to KRAS inhibition. EGFR reactivation has emerged as a principal resistance mechanism to KRAS inhibitor monotherapy. Thus, the field has pivoted to dual EGFR/KRAS blockade with promising efficacy. Despite significant strides in the treatment of KRAS G12C mutated CRC, new challenges are on the horizon. Alternative RTK reactivation and countless acquired molecular resistance mechanisms have shifted the treatment goalpost. This review focuses on the historical and contemporary clinical strategies of targeting KRAS G12C alterations in CRC and highlights future directions to overcome treatment challenges.
    Keywords:  Combination therapies; KRAS G12C inhibitor resistance mechanisms; RAS inhibitors; Targeted therapy
    DOI:  https://doi.org/10.1016/j.clcc.2024.05.004
  15. Cancer Lett. 2024 Jun 05. pii: S0304-3835(24)00401-4. [Epub ahead of print] 217007
    PDP1 promotes KRAS mutant colorectal cancer progression by serving as a scaffold for BRAF and MEK1.
    Ming Yuan, Chi Zhang, Shaopeng Chen, Shubiao Ye, Huashan Liu, Haoxian Ke, Junfeng Huang, Guanzhan Liang, Runfeng Yu, Tuo Hu, Xianrui Wu, Ping Lan.
      The oncogenic role of KRAS in colorectal cancer (CRC) progression is well-established. Despite this, identifying effective therapeutic targets for KRAS-mutated CRC remains a significant challenge. This study identifies pyruvate dehydrogenase phosphatase catalytic subunit 1 (PDP1) as a previously unrecognized yet crucial regulator in the progression of KRAS mutant CRC. A substantial upregulation of PDP1 expression is observed in KRAS mutant CRC cells and tissues compared to wild-type KRAS samples, which correlates with poorer prognosis. Functional experiments elucidate that PDP1 accelerates the malignance of KRAS mutant CRC cells, both in vitro and in vivo. Mechanistically, PDP1 acts as a scaffold, enhancing BRAF and MEK1 interaction and activating the MAPK signaling, thereby promoting CRC progression. Additionally, transcription factor KLF5 is identified as the key regulator for PDP1 upregulation in KRAS mutant CRC. Crucially, targeting PDP1 combined with MAPK inhibitors exhibits an obvious inhibitory effect on KRAS mutant CRC. Overall, PDP1 is underscored as a vital oncogenic driver and promising therapeutic target for KRAS mutant CRC.
    Keywords:  PDP1; colorectal cancer; mutant KRAS; scaffold; sotorasib
    DOI:  https://doi.org/10.1016/j.canlet.2024.217007
  16. Nat Commun. 2024 Jun 05. 15(1): 4771
    Zebrafish Avatar-test forecasts clinical response to chemotherapy in patients with colorectal cancer.
    Bruna Costa, Marta F Estrada, António Gomes, Laura M Fernandez, José M Azevedo, Vanda Póvoa, Márcia Fontes, António Alves, António Galzerano, Mireia Castillo-Martin, Ignacio Herrando, Shermann Brandão, Carla Carneiro, Vítor Nunes, Carlos Carvalho, Amjad Parvaiz, Ana Marreiros, Rita Fior.
      Cancer patients often undergo rounds of trial-and-error to find the most effective treatment because there is no test in the clinical practice for predicting therapy response. Here, we conduct a clinical study to validate the zebrafish patient-derived xenograft model (zAvatar) as a fast predictive platform for personalized treatment in colorectal cancer. zAvatars are generated with patient tumor cells, treated exactly with the same therapy as their corresponding patient and analyzed at single-cell resolution. By individually comparing the clinical responses of 55 patients with their zAvatar-test, we develop a decision tree model integrating tumor stage, zAvatar-apoptosis, and zAvatar-metastatic potential. This model accurately forecasts patient progression with 91% accuracy. Importantly, patients with a sensitive zAvatar-test exhibit longer progression-free survival compared to those with a resistant test. We propose the zAvatar-test as a rapid approach to guide clinical decisions, optimizing treatment options and improving the survival of cancer patients.
    DOI:  https://doi.org/10.1038/s41467-024-49051-0
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