Oncology
Abstract
Fanconi anemia (FA) confers a high risk (~700-fold increase) of solid tumor formation, most often head and neck squamous cell carcinoma (HNSCC). FA germline DNA repair defects preclude administration of most chemotherapies and prior hematopoietic stem cell transplantation limits use of immunotherapy. Thus, surgery and judicious delivery of radiation offer the only treatment options, with most patients succumbing to their cancers. A paucity of preclinical models has limited the development of new treatments. Here, we report, to our knowledge, the first patient-derived xenografts (PDXs) of FA-HNSCC and highlight the efficacy of FDA-approved EGFR targeted therapies in tumors with high EGFR/p-EGFR levels and the activity of the FDA-approved Bcl-2 inhibitor venetoclax in a FA-HNSCC PDX overexpressing Bcl-2. These findings support the development of precision medicine approaches for FA-HNSCC.
Authors
Jennifer Grandis, Hua Li, Benjamin A. Harrison, Andrew L.H. Webster, Joanna Pucilowska, Austin Nguyen, Jinho Lee, Gordon B. Mills, Jovanka Gencel-Augusto, Yan Zeng, Steven R. Long, Mi-Ok Kim, Rex H. Lee, David I. Kutler, Theresa Scognamiglio, Margaret Brandwein-Weber, Mark Urken, Inna Khodos, Elisa de Stanchina, Yu-Chien Lin, Frank X. Donovan, Settara C. Chandrasekharappa, Moonjung Jung, Mathijs A. Sanders, Agata Smogorzewska, Daniel E. Johnson
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) is a master controller of cell growth and its dysregulation is associated with cancer. KICSTOR, a complex comprising KPTN, ITFG2, C12orf66, and SZT2, functions as a critical negative regulator of amino acid-induced mTORC1 activation. However, the regulatory mechanisms governing KICSTOR remain largely unclear. In this study, we identify FBXO2 as a key modulator of amino acid-dependent mTORC1 signaling. Mechanistically, FBXO2 colocalizes and directly interacts with KPTN via its F-box-associated domain, promoting K48- and K63-linked polyubiquitination of KPTN at lysine residues 49, 67, 262, and 265. FBXO2-mediated KPTN ubiquitination disrupts its interaction with ITFG2 and SZT2, while enhancing its interaction with C12orf66, thereby impairing the ability of KICSTOR to recruit the GATOR1 complex to the lysosomal surface. Notably, FBXO2 protein levels are substantially upregulated in liver cancer patients and FBXO2-mediated KPTN ubiquitination facilitates the progression of hepatocellular carcinoma (HCC). These results reveal a key regulatory mechanism of the mTORC1 signaling and highlight FBXO2 and KPTN ubiquitination as therapeutic targets for HCC treatment.
Authors
Jianfang Gao, Jina Qing, Xianglong Li, Yuxuan Luo, Lingwen Huang, Hongxia Li, Huan Zhang, Jiao Zhang, Pei Xiao, Jinsong Li, Tingting Li, Shanping He
Abstract
The metabolic microenvironment plays important roles in tumorigenesis, but how leukemia-initiating cells (LICs) response to the acidic BM niche remains largely unknown. Here, we show that acid-sensing ion channel 3 (ASIC3) dramatically delays leukemogenesis. Asic3 deletion results in a remarkably enhanced self-renewal, reduced differentiation, and 9-fold greater number of murine acute myeloid LICs. We developed an ultrasensitive, ratiometric, genetically encoded fluorescent pH sensor (pHluorin3) and demonstrated that LICs prefer localizing in the endosteal niche with a neutral pH range of 7.34–7.42, but not in the vascular niche with a lower pH range of 6.89–7.22. Unexpectedly, acid-ASIC3 signaling inhibits both murine and human LIC activities in a noncanonical manner by interacting with the N-terminal of STIM1 to reduce calcium-mediated CAMK1-CREB-MEIS1-LDHA levels, without inducing cation currents. This study reveals a pathway in suppression of leukemogenesis in the acidic BM niche and provides insight into targeting LICs or other cancer stem cells through pH-dependent ASICs.
Authors
Hao Gu, Lietao Weng, Chiqi Chen, Xiaoxin Hao, Rongkun Tao, Xin Qi, Xiaoyun Lai, Ligen Liu, Tinghua Zhang, Yiming Jiang, Jin Wang, Wei-Guang Li, Zhuo Yu, Li Xie, Yaping Zhang, Xiaoxiao He, Ye Yu, Yi Yang, Dehua Wu, Yuzheng Zhao, Tian-Le Xu, Guo-Qiang Chen, Junke Zheng
Abstract
Triple-negative breast cancer (TNBC), being both aggressive and highly lethal, poses a major clinical challenge in terms of treatment. Its heterogeneity and lack of hormone receptors or HER2 expression further restrict the availability of targeted therapy. Breast cancer stem cells (BCSCs), known to fuel TNBC malignancy, are now being exploited as a vulnerability for TNBC treatment. Here, we dissected the transcriptome of BCSCs and identified kinesin family member 20A (KIF20A) as a key regulator of BCSC survival and TNBC tumorigenesis. Genetic depletion or pharmacological inhibition of KIF20A impairs BCSC viability and tumor initiation and development in vitro and in vivo. Mechanistically, KIF20A supports BCSC stemness through modulation of mitochondrial oxidative phosphorylation, which is repressed by SMARCA4, a component of the SWI/SNF chromatin remodeling complex. Therapeutically, KIF20A inhibition sensitizes TNBC xenografts to standard-of-care chemotherapy. Our study highlights the importance of targeting KIF20A to exploit BCSC vulnerabilities in TNBC.
Authors
Yayoi Adachi, Weilong Chen, Cheng Zhang, Tao Wang, Nina Gildor, Rachel Shi, Haoyong Fu, Masashi Takeda, Qian Liang, Fangzhou Zhao, Hongyi Liu, Jun Fang, Jin Zhou, Hongwei Yao, Lianxin Hu, Shina Li, Lei Guo, Lin Xu, Ling Xie, Xian Chen, Chengheng Liao, Qing Zhang
Abstract
Genome instability is most commonly caused by replication stress, which also renders cancer cells extremely vulnerable once their response to replication stress is impeded. Topoisomerase II binding protein 1 (TOPBP1), an allosteric activator of ataxia telangiectasia and Rad3-related kinase (ATR), coordinates ATR in replication stress response and has emerged as a potential therapeutic target for tumors. Here, we identify auranofin, the FDA-approved drug for rheumatoid arthritis, as a lead compound capable of binding to the BRCT 7–8 domains and blocking TOPBP1 interaction with PHF8 and FANCJ. The liquid-liquid phase separation of TOPBP1 is also disrupted by auranofin. Through targeting these TOPBP1-nucleated molecular machineries, auranofin leads to an accumulation of replication defects by impairing ATR activation and attenuating replication protein A loading on perturbed replication forks, and it shows significant anti–breast tumor activity in combination with a PARP inhibitor. This study provides mechanistic insights into how auranofin challenges replication integrity and expands the application of this FDA-approved drug in breast tumor intervention.
Authors
Shuai Ma, Yingying Han, Rui Gu, Qi Chen, Qiushi Guo, Yuan Yue, Cheng Cao, Ling Liu, Zhenzhen Yang, Yan Qin, Ying Yang, Kai Zhang, Fei Liu, Lin Liu, Na Yang, Jihui Hao, Jie Yang, Zhi Yao, Xiaoyun Mao, Lei Shi
Abstract
Over 15% of cancers worldwide are caused by viruses. Merkel cell polyomavirus (MCPyV) is the most recently discovered human oncovirus and is the only polyomavirus that drives malignant tumors in humans. Here, we show that MCPyV+ Merkel cell carcinoma is defined by neuroendocrine-lineage core regulatory (CR) transcription factors (TFs) (ATOH1, INSM1, ISL1, LHX3, POU4F3, and SOX2) that were essential for tumor survival and that co-bound chromatin with the viral small T antigen at super enhancers. Moreover, MCPyV integration sites were enriched at these neuroendocrine super enhancers. We further discovered that the MCPyV noncoding control region contained a homeodomain binding motif absent in other polyomaviruses that bound ISL1 and LHX3 and depended on them for T antigen expression. To therapeutically target the CR factors, we used histone deacetylase (HDAC) inhibitors to collapse the chromatin architecture and induce topological blurring of superenhancer loops, abrogating core TF expression and halting tumor growth. To our knowledge, our study presents the first example of oncogenic cross-regulation between viral and human epigenomic circuitry to generate interlocking and essential transcriptional feedback circuits that explain why MCPyV causes neuroendocrine cancer and represent a tumor dependency that can be targeted therapeutically.
Authors
Lingling Miao, David Milewski, Amy Coxon, Tara Gelb, Khalid A. Garman, Jadon Porch, Arushi Khanna, Loren Collado, Natasha T. Hill, Kenneth Daily, Serena Vilasi, Danielle Reed, Tiffany Alexander, Gabriel J. Starrett, Maharshi Chakraborty, Young Song, Rachel Choi, Vineela Gangalapudi, Josiah Seaman, Andrew Morton, Klaus J. Busam, Christopher R. Vakoc, Daniel J. Urban, Min Shen, Matthew D. Hall, Richard Sallari, Javed Khan, Berkley E. Gryder, Isaac Brownell
Abstract
Metabolic dysfunction–associated steatotic liver disease–induced (MASLD-induced) hepatocellular carcinoma (HCC) is an emerging malignancy linked to excessive accumulation of adipose tissue and hepatic fat. Understanding the role of adipocytes in the development of MASLD-induced HCC is crucial. In an in vitro coculture system, differentiated adipocytes were found to enhance cancer stemness and drug resistance in HCC through paracrine signaling. Fatty acid–binding protein 4 (FABP4) was preferentially secreted by adipocytes, and recombinant FABP4 further augmented the cancer stem cell (CSC) properties of HCC cells. Notably, Fabp4–/– mice exhibited a marked delay in the progression of MASLD-HCC, which correlated with the increased HCC risk observed in MASLD patients with elevated FABP4 expression. Mass spectrometry analysis identified integrin β 1 (ITGB1) as a binding partner of FABP4. These data, together with a substantial downregulation of the Wnt/β-catenin pathway in Fabp4–/– mouse tumors, revealed that FABP4 augmented liver CSC functions by activating PI3K/AKT/β-catenin signaling via ITGB1. We developed an anti-FABP4 neutralizing antibody that successfully inhibited FABP4-driven CSC functions and suppressed MASLD-induced HCC. In conclusion, our findings indicate that adipocyte-derived FABP4 plays a critical role in the development of MASLD-induced HCC and targeting the ITGB1/PI3K/AKT/β-catenin signaling cascade may offer a promising approach to combat this aggressive disease.
Authors
Carmen Oi Ning Leung, Shilpa Gurung, Katherine Po Sin Chung, Rainbow Wing Hei Leung, Martina Mang Leng Lei, Mandy Sze Man Chan, Gregory Kenneth Muliawan, Shakeel Ahmad Khan, Xue Qian Wu, Jun Yu, Hui Lian Zhu, Yin Ying Lu, Stephanie Ma, Xiaoping Wu, Ruby Lai Chong Hoo, Terence Kin Wah Lee
Abstract
KRAS mutations serve as key oncogenic drivers in the initiation and progression of pancreatic ductal adenocarcinoma (PDAC). Despite the advancement of KRAS inhibitors like MRTX1133 for PDAC treatment, intrinsic and acquired resistance remain major barriers to their clinical efficacy. This study underscored the role of histone deacetylase 5 (HDAC5) loss in mediating intrinsic resistance to KRASG12D inhibitors. Mechanistically, HDAC5 promoted c-Myc degradation by deacetylating K148, thereby facilitating NEDD4-mediated ubiquitination at this site. The loss of HDAC5 resulted in hyperacetylation of c-Myc at K148, impeding the ubiquitination and subsequent degradation process of c-Myc following deacetylation. Consequently, c-Myc stability and transcriptional activity were sustained even under KRAS-MEK-ERK pathway inhibition, reinforcing MAPK signaling and promoting cell survival despite KRAS suppression. Our data further demonstrated that pharmacological or genetic inhibition of c-Myc effectively reversed the resistance phenotype mediated by HDAC5 loss, suggesting a therapeutic strategy centered on "KRAS-MYC dual-node blockade." Furthermore, the expression levels of HDAC5 and the acetylation status of c-Myc may serve as potential biomarkers for predicting the therapeutic response to MRTX1133. These findings provide insights into overcoming resistance to KRASG12D inhibitors and offer potential biomarkers and combinatorial therapeutic strategies for precision treatment of PDAC.
Authors
Taoyu Chen, Haixin Yu, Keshan Wang, Gengdu Qin, Yuhan Zhao, Xueyi Liang, Yuxuan Li, Tianhao Zou, Jiaying Liu, Jingyuan Zhao, Zhiqiang Liu, Ruozheng Wei, Bo Wang, Shanmiao Gou, Tao Yin, Heshui Wu, Xin Jin, Yingke Zhou
Abstract
The role of the tumor immune microenvironment (TIME) in modulating responses to antiestrogen therapy in hormone receptor-positive (HR+) breast cancers remains unclear. We analyzed pre- and on-treatment biopsies from patients with HR+ breast cancer treated with letrozole to induce estrogen deprivation (ED). Stromal tumor-infiltrating lymphocytes, assessed by H&E-staining, and immune-related gene sets, including IFNɣ signaling, measured by RNA sequencing, were increased in ED-resistant tumors. Cyclic immunofluorescence and spatial transcriptomics revealed an abundance of CD8+ T cells and enhanced antigen processing and immune gene signatures in ED-resistant tumors. In this group, the expression of CXCL9, CXCL10, and CXCL11 — chemokine genes involved in CD8+ T cell recruitment — and the CXCR3 receptor were upregulated both before and after letrozole. CXCL11 levels were higher in conditioned media from HR+ breast cancer cells co-cultured with CD8+ T cells. Both recombinant CXCL11 and co-culture with CD8+ T cells promoted MCF7 and T47D cell growth in estrogen-free conditions. Finally, deletion combined with silencing of the CXCL11 receptors CXCR3 and CXCR7 in MCF7 cells impaired proliferation in response to exogenous CXCL11 and to co-culture with CD8+ T cells in estrogen-free conditions. These findings suggest that CD8+ T cell-associated CXCL11 in the TIME modulates the response of HR+ breast cancer cells to estrogen suppression.
Authors
Fabiana Napolitano, Yunguan Wang, Dhivya R. Sudhan, Paula I. Gonzalez-Ericsson, Luigi Formisano, Nisha Unni, Shahbano Shakeel, James Z. Zhu, Khushi Ahuja, Lei Guo, María Rosario Chica-Parrado, Yuki Matsunaga, Pamela Luna, Chang-Ching A. Lin, Yasuaki Uemoto, Kyung-Min Lee, Hongli Ma, Nathaniel J. Evans, Alberto Servetto, Saurabh Mendiratta, Spencer D. Barnes, Roberto Bianco, Yisheng V. Fang, Lin Xu, Jeon Lee, Tao Wang, Justin M. Balko, Gordon B. Mills, Marilyne Labrie, Ariella B. Hanker, Carlos L. Arteaga
Abstract
Adoptive cell therapy (ACT) relies on durable and functional T cells to mediate tumor clearance. Th9 cells are a metabolically fit CD4+ T cell subset with strong persistence but limited cytotoxicity. Here, we identified endomelipeptide A (EpA), a cyclic peptide isolated from Ganoderma lucidum–associated endophytic fungi, as a potent enhancer of Th9 differentiation. EpA promoted a cytotoxic Th9 phenotype with enhanced mitochondrial function and metabolic fitness. Mechanistically, EpA dually targeted ZAP70 and SREBP1, coupling T cell receptor (TCR) signaling activation with lipid metabolism suppression. EpA-treated Th9 cells mediated robust, CD8+ T cell–dependent tumor control and enhanced the efficacy of human Th9 CAR-T therapy in vivo. These findings establish EpA as a distinct cyclic peptide that reprograms Th9 cells and provides a potential approach to boost ACT efficacy.
Authors
Wenli Zhao, Yang Zhou, Yuyang Chen, Yicheng Sun, Jiaxin Tang, Yihan Zhu, Jie Ren, Tianxu Du, Handuo Wang, Yuan Gao, Yu Hu, Ling Jiang, Tomohiko Ohwada, Qi Luo, Enguang Bi
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)