Islam, Rawnsley, and colleagues report that phosphorylation of CRYAB, a cardiac myocyte–enriched chaperone protein, after myocardial infarction promotes protein aggregates and contributes to heart failure. The cover image depicts abnormal condensates driven by phosphorylated CRYAB (blue on red) molecules that trap desmin (yellow) to form aggregates. This prevents the physiologic localization of desmin as a scaffold holding linear arrays of sarcomeres (pink) together, causing sarcomere disarray and cardiomyopathy. Image credit: Anthony Bartley.
Telomere biology disorders (TBD) are genetic diseases caused by defective telomere maintenance. TBD patients often develop bone marrow failure and have an increased risk of myeloid neoplasms. To better understand the factors underlying hematopoietic outcomes in TBD, we comprehensively evaluated acquired genetic alterations in hematopoietic cells from 166 pediatric and adult TBD patients. 47.6% of patients (28.8% of children, 56.1% of adults) had clonal hematopoiesis. Recurrent somatic alterations involved telomere maintenance genes (7.6%), spliceosome genes (10.4%, mainly U2AF1 p.S34), and chromosomal alterations (20.2%), including 1q gain (5.9%). Somatic variants affecting the DNA damage response (DDR) were identified in 21.5% of patients, including 20 presumed loss-of-function variants in ATM. Using multimodal approaches, including single-cell sequencing, assays of ATM activation, telomere dysfunction-induced foci analysis, and cell growth assays, we demonstrate telomere dysfunction-induced activation of ATM-dependent DDR pathway with increased senescence and apoptosis in TBD patient cells. Pharmacologic ATM inhibition, modeling the effects of somatic ATM variants, selectively improved TBD cell fitness by allowing cells to bypass DDR-mediated senescence without detectably inducing chromosomal instability. Our results indicate that ATM-dependent DDR induced by telomere dysfunction is a key contributor to TBD pathogenesis and suggest dampening hyperactive ATM-dependent DDR as a potential therapeutic intervention.
Christopher M. Sande, Stone Chen, Dana V. Mitchell, Ping Lin, Diana M. Abraham, Jessie M. Cheng, Talia Gebhard, Rujul J. Deolikar, Colby Freeman, Mary Zhou, Sushant Kumar, Michael Bowman, Robert L. Bowman, Shannon Zheng, Bolormaa Munkhbileg, Qijun Chen, Natasha L. Stanley, Kathy Guo, Ajibike Lapite, Ryan Hausler, Deanne M. Taylor, James Corines, Jennifer J.D. Morrissette, David B. Lieberman, Guang Yang, Olga Shestova, Saar Gill, Jiayin Zheng, Kelcy Smith-Simmer, Lauren G. Banaszak, Kyle N. Shoger, Erica F. Reinig, Madilynn Peterson, Peter Nicholas, Amanda J. Walne, Inderjeet Dokal, Justin P. Rosenheck, Karolyn A. Oetjen, Daniel C. Link, Andrew E. Gelman, Christopher R. Reilly, Ritika Dutta, R. Coleman Lindsley, Karyn J. Brundige, Suneet Agarwal, Alison A. Bertuch, Jane E. Churpek, Laneshia K. Tague, F. Brad Johnson, Timothy S. Olson, Daria V. Babushok
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.
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
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.
Qing Liao, Ximing Zhou, Ling Wu, Yuyi Yang, Xiaohui Zhu, Hangyu Liao, Yujie Zhang, Weidong Lian, Feifei Zhang, Hui Wang, Yanqing Ding, Liang Zhao
Anna S. Pollack, Christian A. Kunder, Chandler C. Ho, Josephine Chou, Andrew J. Pollack, Rachel L. P. Geisick, Bing M. Zhang, Robert B. West, James D. Brooks, Jonathan R. Pollack
Hyaluronan (HA) in the extracellular matrix promotes epithelial-to-mesenchymal transition (EMT) and metastasis; however, the mechanism by which the HA network constructed by cancer cells regulates cancer progression and metastasis in the tumor microenvironment (TME) remains largely unknown. In this study, inter-alpha-trypsin inhibitor heavy chain 2 (ITIH2), an HA-binding protein, was confirmed to be secreted from mesenchymal-like lung cancer cells when co-cultured with cancer-associated fibroblasts. ITIH2 expression is transcriptionally upregulated by the EMT-inducing transcription factor ZEB1, along with HA synthase 2 (HAS2), which positively correlates with ZEB1 expression. Depletion of ITIH2 and HAS2 reduced HA matrix formation and the migration and invasion of lung cancer cells. Furthermore, ZEB1 facilitates alternative splicing and isoform expression of CD44, an HA receptor, and CD44 knockdown suppresses the motility and invasiveness of lung cancer cells. Using a deep learning-based drug-target interaction algorithm, we identified an ITIH2 inhibitor (sincalide) that inhibited HA matrix formation and migration of lung cancer cells, preventing metastatic colonization of lung cancer cells in mouse models. These findings suggest that ZEB1 remodels the HA network in the TME through the regulation of ITIH2, HAS2, and CD44, presenting a strategy for targeting this network to suppress lung cancer progression.
Sieun Lee, Jihye Park, Seongran Cho, Eun Ju Kim, Seonyeong Oh, Younseo Lee, Sungsoo Park, Keunsoo Kang, Dong Hoon Shin, Song Yi Ko, Jonathan M. Kurie, Young-Ho Ahn
Metabolic dysfunction associated steatotic liver disease (MASLD, formerly called NAFLD) and its more advanced form, metabolic dysfunction associated steatohepatitis (MASH, formerly called NASH) are increasing in prevalence worldwide as the number of individuals with metabolic risk factors rises. These diseases and their adverse sequelae have a formidable economic impact, and there remain large gaps in understanding and treating MASLD/MASH. Series editor Scott Friedman curated this series of expert-led review articles to cover advances and challenges across the spectrum of basic investigation to clinical trials. The reviews will address diagnostic approaches, management strategies specific to adolescent and pregnant individuals, pathobiology, and therapeutic horizons, with the goal of reflecting the heterogeneity seen in disease drivers as well as the affected population.
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