Gastroenterology
Abstract
The Wnt/β-catenin pathway regulates expression of the SOX9 gene, which encodes SRY-box transcription factor 9, a differentiation factor and potential β-catenin regulator. Because APC tumor suppressor defects in ~80% of colorectal cancers (CRCs) activate the Wnt/β-catenin pathway, we studied SOX9 inactivation in CRC biology. Compared to effects of Apc inactivation in mouse colon tumors, combined Apc and Sox9 inactivation instigated more invasive tumors with epithelial-mesenchymal transition (EMT) and SOX2 stem cell factor upregulation. In an independent mouse CRC model with combined Apc, Kras, and Trp53 defects, Sox9 inactivation promoted SOX2 induction and distant metastases. About 20% of 171 human CRCs showed loss of SOX9 protein expression, which correlated with higher tumor grade. In an independent group of 376 CRC patients, low SOX9 gene expression was linked to poor survival, earlier age at diagnosis, and increased lymph node involvement. SOX9 expression reductions in human CRC were linked to promoter methylation. EMT pathway gene expression changes were prominent in human CRCs with low SOX9 expression and in a mouse cancer model with high SOX2 expression. Our results indicate SOX9 has tumor suppressor function in CRC; its loss may promote progression, invasion, and poor prognosis by enhancing EMT and stem cell phenotypes.
Authors
Ying Feng, Ningxin Zhu, Karan Bedi, Jinju Li, Chamila Perera, Maranne Green, Naziheh Assarzadegan, Yali Zhai, Qingzhi Liu, Veerabhadran Baladandayuthapani, Jason R. Spence, Kathleen R. Cho, Eric R. Fearon
Abstract
Colorectal cancer (CRC) is characterized by an immune-suppressive microenvironment that contributes to tumor progression and immunotherapy resistance. The gut microbiome produces diverse metabolites that feature unique mechanisms of interaction with host targets, yet the role of many metabolites in CRC remains poorly understood. In this study, the microbial metabolite 4-hydroxybenzeneacetic acid (4-HPA) promoted the infiltration of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) in the tumor microenvironment, consequently inhibiting the anti-tumor response of CD8+ T cells and promoting CRC progression in vivo. Mechanistically, 4-HPA activates the JAK2/STAT3 pathway, which upregulates CXCL3 transcription, thereby recruiting PMN-MDSCs to the CRC microenvironment. Selective knockdown of CXCL3 re-sensitized tumors to anti-PD1 immunotherapy in vivo. Chlorogenic acid (CGA) reduces the production of 4-HPA by microbiota, likewise abolishing 4-HPA-mediated immunosuppression. The 4-HPA content in CRC tissues was notably increased in patients with advanced CRC. Overall, the gut microbiome uses 4-HPA as a messenger to control chemokine-dependent accumulation of PMN-MDSC cells and regulate anti-tumor immunity in CRC. Our findings provide a scientific basis for establishing clinical intervention strategies to reverse the tumor immune microenvironment and improve the efficacy of immunotherapy by reducing the interaction between intestinal microbiota, tumor cells and tumor immune cells.
Authors
Qing Liao, Ximing Zhou, Ling Wu, Yuyi Yang, Xiaohui Zhu, Hangyu Liao, Yujie Zhang, Weidong Lian, Feifei Zhang, Hui Wang, Yanqing Ding, Liang Zhao
Abstract
Colorectal cancer (CRC) remains a leading cause of cancer death due to metastatic spread. LIN28B is overexpressed in 30% of CRCs and promotes metastasis, yet its mechanisms remain unclear. In this study, we genetically modified CRC cell lines to overexpress LIN28B, resulting in enhanced PI3K/AKT pathway activation and liver metastasis in mice. We developed genetically modified mouse models with constitutively active Pik3ca that form intestinal tumors progressing to liver metastases with an intact immune system, addressing the limitations of previous Pik3ca-mutant models, including long tumor latency, mixed histology, and lack of distant metastases. The PI3Kα-specific inhibitor alpelisib reduced migration and invasion in vitro and metastasis in vivo. We present the first comprehensive analysis of vertical inhibition of the PI3K/AKT pathway in CRC using FDA-approved drugs alpelisib and capivasertib (an AKT inhibitor) in combination with LY2584702 (an S6K inhibitor) in CRC cell lines and mouse- and patient-derived organoids (PDOs). Tissue microarrays from CRC patients confirmed that LIN28B and PI3K/AKT pathway activation correlate with CRC progression. These findings highlight the critical role of the LIN28B-mediated PI3K/AKT pathway in CRC metastasis, the therapeutic potential of targeted inhibition, and the promise of PDOs in precision medicine in metastatic CRC.
Authors
Alice E. Shin, Kensuke Sugiura, Secunda W. Kariuki, David A. Cohen, Samuel P. Flashner, Andres J. Klein-Szanto, Noriyuki Nishiwaki, Dechokyab De, Neil Vasan, Joel T. Gabre, Christopher J. Lengner, Peter A. Sims, Anil K. Rustgi
Abstract
Intestinal stem cells are crucial for maintaining intestinal homeostasis, yet their transformation into tumor stem cells in the context of microbial infection remains poorly understood. Fusobacterium nucleatum (F. nucleatum) is frequently associated with the onset and progression of colorectal cancer (CRC). In this study, we uncovered that F. nucleatum colonized the depths of gut crypts in both human CRC patients and mouse models. Through single-cell sequencing analysis, we demonstrated that F. nucleatum infection reprogrammed crypt cells and activated LY6A+ revival stem cells (RSCs), promoting their hyperproliferation and subsequent transformation into tumor stem cells, which accelerated intestinal carcinogenesis. Mechanistically, we identified LY6A as a GPI-anchored membrane receptor for F. nucleatum. Upon binding, F. nucleatum induced upregulation of RPS14 via the LY6A receptor, driving RSC hyperactivity and tumorigenic conversion. Functional studies showed that genetic ablation of Ly6a in intestinal epithelial cells or Rps14 in LY6A+ RSCs substantially reduced F. nucleatum colonization and tumorigenesis. Moreover, clinical CRC cohorts analysis revealed a strong correlation between F. nucleatum infection, RSC expansion, and elevated RPS14 expression in tumor tissues. These findings highlight an alternative F. nucleatum-LY6A-RPS14 signaling axis as a critical driver of CRC progression and propose potential therapeutic targets for effective CRC intervention.
Authors
Qinying Wang, Tingting Hu, Qinyuan Zhang, Yichi Zhang, Xiaoxu Dong, Yutao Jin, Jinming Li, Yangyang Guo, Fanying Guo, Ziying Chen, Peijie Zhong, Yongzhi Yang, Yanlei Ma
Abstract
Background: While most hypertriglyceridemia is asymptomatic, hypertriglyceridemia-associated acute pancreatitis (HTG-AP) can be more severe than other AP etiologies. The reasons underlying this are unclear. We thus studied whether lipolytic generation of non-esterified fatty acids (NEFA) from circulating triglycerides (TGs) could worsen clinical outcomes. Methods: Admission serum TGs, NEFA compositions and concentrations were analyzed prospectively in 269 patients with AP. These and demographics, clinical outcomes were compared between HTGAP (TGs >500mg/dL; American Heart Association 2018 guidelines) and other AP etiologies. Serum NEFAs were correlated with the serum triglyceride fatty acids (TGFAs) alone, and with the product of TGFA x serum lipase (NEFA-TGFA x lipase). Studies in mice, rats were done to understand the role of HTG lipolysis in organ failure and to interpret the NEFA-TGFA correlations. Results: HTG-AP patients had higher serum NEFAs and TGs and more severe AP (19% vs. 7% p<0.03) than other etiologies. Correlations of long-chain unsaturated NEFA with corresponding TGFAs increased with TG concentrations up to 500mg/dL and declined thereafter. However, NEFA-TGFA x lipase correlations got stronger with TGs >500mg/dL. AP, and intravenous lipase infusion in rodents caused lipolysis of circulating TGs to NEFA. This led to multi-system organ failure, which was prevented by pancreatic triglyceride lipase deletion, or lipase inhibition. Conclusions: HTG-AP is made severe by the NEFAs generated form intravascular lipolysis of circulating TGs. Strategies that prevent TG lipolysis may be effective in improving clinical outcomes of HTG-AP. Trial registration: Not applicable. Funding: This project was supported by Grant numbers RO1DK092460, R01DK119646 from the NIDDK, PR191945 under W81XWH-20-1-0400 from the DOD (VPS), and R01AA031257 from the NIAAA (VPS).
Authors
Prasad Rajalingamgari, Biswajit Khatua, Megan J. Summers, Sergiy Kostenko, Yu-Hui H Chang, Mohamed Elmallahy, Arti Anand, Anoop Narayana Pillai, Mahmoud Morsy, Shubham Trivedi, Bryce McFayden, Sarah Jahangir, Christine LH Snozek, Vijay P. Singh
Abstract
BRAFV600E-mutant metastatic colorectal cancer (mCRC) is associated with poor prognosis. The combination of anti-BRAF/EGFR (encorafenib/cetuximab) treatment for patients with BRAFV600E-mutant mCRC improved clinical benefits; unfortunately, inevitable acquired resistance limits the treatment outcome, and the mechanism has not been validated. Here, we discovered that monoacylglycerol O-Acyltransferase 3 (MOGAT3) mediated diacylglycerol (DAG) accumulation contributed to acquired resistance to encorafenib/cetuximab by dissecting BRAFV600E-mutant mCRC patient-derived xenograft (PDX) model exposed to encorafenib/cetuximab administration. Mechanistically, upregulated MOGAT3 promotes DAG synthesis and reduces fatty acid oxidation (FAO)-promoting DAG accumulation and activating PKCα-CRAF-MEK-ERK, driving acquired resistance. Resistance-induced hypoxia promotes MOGAT3 transcriptional elevation; simultaneously, MOGAT3-mediated DAG accumulation increases HIF1A expression in translation level through PKCα-CRAF-eIF4E activation, strengthening the resistance status. Intriguingly, reducing intratumoral DAG by fenofibrate or Pf-06471553 restores the antitumor efficacy of encorafenib/cetuximab on resistant BRAFV600E-mutant mCRC, interrupted PKCα-CRAF-MEK-ERK signaling. These findings reveal the critical metabolite DAG as a modulator of encorafenib/cetuximab efficacy in BRAFV600E-mutant mCRC, suggesting that fenofibrate may prove beneficial for resistant BRAFV600E-mutant mCRC patients.
Authors
Jiawei Wang, Huogang Wang, Wei Zhou, Xin Luo, Huijuan Wang, Qing Meng, Jiaxin Chen, Xiaoyu Chen, Yinqiang Liu, David W. Chan, Zhenyu Ju, Zhangfa Song
Abstract
Intestinal dysmotility syndromes have been epidemiologically associated with several antecedent bacterial and viral infections. To model this phenotype, we previously infected mice with the neurotropic flavivirus, West Nile Virus (WNV) and demonstrated intestinal transit defects. Here, we find that within one week of WNV infection, enteric neurons and glia become damaged, resulting in sustained reductions of neuronal cells and their networks of connecting fibers. Using cell-depleting antibodies, adoptive transfer experiments, and mice lacking specific immune cells or immune functions, we show that infiltrating WNV-specific CD4+ and CD8+ T cells damage the enteric nervous system (ENS) and glia, which leads to intestinal dysmotility; these T cells use multiple and redundant effector functions including perforin and Fas ligand. In comparison, WNV-triggered ENS injury and intestinal dysmotility appears to not require infiltrating monocytes and damage may be limited by resident muscularis macrophages. Overall, our experiments support a model whereby antigen specific T cell subsets and their effector molecules responding to WNV infection direct immune pathology against enteric neurons and supporting glia that results in intestinal dysmotility.
Authors
Hana Janova, Fang R. Zhao, Pritesh Desai, Matthias Mack, Larissa B. Thackray, Thaddeus S. Stappenbeck, Michael S. Diamond
Abstract
Crohn's disease (CD) is marked by recurring intestinal inflammation and tissue injury, often resulting in fibro-stenosis and bowel obstruction, necessitating surgical intervention with high recurrence rates. To elucidate to the mechanisms underlying fibro-stenosis in CD, we analysed the transcriptome of cells isolated from the transmural ileum of CD patients, including a trio of lesions from each patient: non-affected, inflamed, and stenotic ileum samples, and compared them with samples from non-CD patients. Our computational analysis revealed that pro-fibrotic signals from a subset of monocyte-derived cells expressing CD150 induced a disease-specific fibroblast population, resulting in chronic inflammation and tissue fibrosis. The transcription factor TWIST1 was identified as a key modulator of fibroblast activation and extracellular matrix (ECM) deposition. Genetic and pharmacological inhibition of TWIST1 prevents fibroblast activation, reducing ECM production and collagen deposition. Our findings suggest that the myeloid-stromal axis may offer a promising therapeutic target to prevent fibro-stenosis in CD.
Authors
Bo-Jun Ke, Saeed Abdurahiman, Francesca Biscu, Gaia Zanella, Gabriele Dragoni, Sneha Santhosh, Veronica De Simone, Anissa Zouzaf, Lies van Baarle, Michelle Stakenborg, Veronika Bosáková, Yentl Van Rymenant, Emile Verhulst, Sare Verstockt, Elliott Klein, Gabriele Bislenghi, Albert M. Wolthuis, Jan Frič, Christine Breynaert, Andre D'Hoore, Pieter Van der Veken, Ingrid De Meester, Sara Lovisa, Lukas J.A.C. Hawinkels, Bram Verstockt, Gert De Hertogh, Séverine Vermeire, Gianluca Matteoli
Abstract
Intestinal fibrosis, a severe complication of Crohn’s disease (CD), is characterized by excessive extracellular matrix (ECM) deposition and induces intestinal strictures, but there are no effective anti-fibrosis drugs available for clinical application. We performed single-cell RNA sequencing (scRNA-seq) of fibrotic and non-fibrotic ileal tissues from CD patients with intestinal obstruction. Analysis revealed mesenchymal stromal cells (MSCs) as the major producers of ECM and the increased infiltration of its subset FAP+ fibroblasts in fibrotic sites, which was confirmed by immunofluorescence and flow cytometry. Single cell transcriptomic profiling of chronic Dextran Sulfate Sodium Salt (DSS) murine colitis model revealed Cd81+Pi16– fibroblasts exhibited transcriptomic and functional similarities to human FAP+ fibroblasts. Consistently, FAP+ fibroblasts were identified as the key subtype with the highest level of ECM production in fibrotic intestines. Furthermore, specific knockout or pharmacological inhibition of TWIST1, which was highly expressed by FAP+ fibroblasts, could significantly ameliorate fibrosis in mice. In addition, TWIST1 expression was induced by CXCL9+ macrophages enriched in fibrotic tissues via IL-1β and TGF-β signal. These findings suggest the inhibition of TWIST1 as a promising strategy for CD fibrosis treatment.
Authors
Yao Zhang, Jiaxin Wang, Hongxiang Sun, Zhenzhen Xun, Zirui He, Yizhou Zhao, Jingjing Qi, Sishen Sun, Qidi Yang, Yubei Gu, Ling Zhang, Chunhua Zhou, Youqiong Ye, Ningbo Wu, Duowu Zou, Bing Su
Abstract
Group 3 innate lymphoid cells (ILC3s) are key players in intestinal homeostasis. Endoplasmic reticulum (ER) stress is linked to inflammatory bowel disease (IBD). Herein, we used cell culture, mouse models, and human specimens to examine if ER stress in ILC3s impacts IBD pathophysiology. We show that mouse intestinal ILC3s exhibited a 24h-rhythmic expression pattern of the master ER stress response regulator, IRE1α/XBP1. Proinflammatory cytokine IL-23 selectively stimulated IRE1α/XBP1 in mouse ILC3s through mitochondrial reactive oxygen species (mtROS). IRE1α/XBP1 was activated in ILC3s of mice exposed to experimental colitis and in inflamed human IBD specimens. Mice with Ire1α deletion in ILC3s (Ire1αΔRorc) showed reduced expression of ER stress response and cytokine genes including Il22 in ILC3s and were highly vulnerable to infections and colitis. Administration of IL-22 counteracted their colitis susceptibility. In human ILC3s, IRE1 inhibitors suppressed cytokine production, which was upregulated by an IRE1 activator. Moreover, the frequencies of intestinal XBP1s+ ILC3s in Crohn’s disease patients before administration of ustekinumab, an anti-IL-12/IL-23 antibody, positively correlated with response to treatment. We demonstrate that a non-canonical mtROS-IRE1α/XBP1 pathway augments cytokine production by ILC3s and identify XBP1s+ ILC3s as a potential biomarker for predicting response to anti-IL-23 therapies in IBD.
Authors
Siyan Cao, Jose Luis Fachi, Kaiming Ma, Alina Ulezko Antonova, Qianli Wang, Zhangying Cai, Randal J. Kaufman, Matthew A Ciorba, Parakkal Deepak, Marco Colonna
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)