Oncology
Abstract
Merkel Cell Carcinoma (MCC) is an aggressive neuroendocrine cutaneous malignancy arising from either ultraviolet-induced mutagenesis or Merkel cell polyomavirus (MCPyV) integration. Despite extensive research, our understanding of the molecular mechanisms driving the transition from normal cells to MCC remains limited. To address this knowledge gap, we assessed the impact of inducible MCPyV T antigens on normal human fibroblasts by performing RNA sequencing. Our data uncovered changes in expression and regulation of Wnt signaling pathway members. Building on this observation, we bioinformatically evaluated various Wnt pathway perturbagens for their ability to reverse the MCC gene expression signature and identified pyrvinium pamoate, an FDA-approved anthelminthic drug known for its anti-tumor activity in other cancers. Leveraging transcriptomic, network, and molecular analyses, we found that pyrvinium targets multiple MCC vulnerabilities. Pyrvinium not only reverses the neuroendocrine features of MCC by modulating canonical and non-canonical Wnt signaling but also inhibits cancer cell growth by activating p53-mediated apoptosis, disrupting mitochondrial function, and inducing endoplasmic reticulum stress. Finally, we demonstrated that pyrvinium reduces tumor growth in an MCC mouse xenograft model. These findings offer a new understanding of the role of Wnt signaling in MCC and highlight the utility of pyrvinium as a potential treatment for MCC.
Authors
Jiawen Yang, James T. Lim, Paul Victor Santiago Raj, Marcelo G. Corona, Chen Chen, Hunain Khawaja, Qiong Pan, Gillian D. Paine-Murrieta, Rick G. Schnellmann, Denise J. Roe, Prafulla C. Gokhale, James A. DeCaprio, Megha Padi
Abstract
Serotonin (5-HT) is a neurotransmitter that has been linked to tumorigenesis. Whether and how 5-HT modulates cells in the microenvironment to regulate tumor metastasis remains to be largely unknown. Here, we demonstrate that 5-HT is secreted by neuroendocrine prostate cancer (NEPC) cells to communicate with neutrophils and to induce neutrophil extracellular traps (NETs) in the liver, which in turn facilitates the recruitment of disseminated cancer cells and promotes liver metastasis. 5-HT induces histone serotonylation (H3Q5ser) and orchestrates histone citrullination (H3cit) in neutrophils to trigger chromatin decondensation and facilitate the formation of NETs. Interestingly, we uncover in this process a reciprocally reinforcing effect between H3Q5ser and H3cit and a crosstalk between the respective writers TGM2 and PAD4. Genetic ablation or pharmacological targeting of TGM2, or inhibiting 5-HT transporter (SERT) with the FDA-approved antidepressant drug fluoxetine reduces H3Q5ser and H3cit modifications, suppresses NETs formation, and effectively inhibits NEPC, small cell lung cancer, and thyroid medullary cancer liver metastasis. Collectively, the 5-HT-triggered NETs production highlights a new targetable neurotransmitter-immune axis in driving liver metastasis of neuroendocrine cancers.
Authors
Kaiyuan Liu, Yingchao Zhang, Genyu Du, Xinyu Chen, Lingling Xiao, Luyao Jiang, Na Jing, Penghui Xu, Chaoxian Zhao, Yiyun Liu, Huifang Zhao, Yujiao Sun, Jinming Wang, Chaping Cheng, Deng Wang, Jiahua Pan, Wei Xue, Pengcheng Zhang, Zhi-Gang Zhang, Wei-Qiang Gao, Shu-Heng Jiang, Kai Zhang, Helen He Zhu
Abstract
Mutated tumor cells undergo changes in chromatin accessibility and gene expression, resulting in aberrant proliferation and differentiation, although how this occurs is unclear. HMGA1 chromatin regulators are abundant in stem cells and oncogenic in diverse tissues; however, their role in colon tumorigenesis is only beginning to emerge. Here, we uncover a previously unknown epigenetic program whereby HMGA1 amplifies Wnt signaling during colon tumorigenesis driven by inflammatory microbiota and/or Adenomatous polyposis coli (Apc) inactivation. Mechanistically, HMGA1 “opens” chromatin to upregulate the stem cell regulator, Ascl2, and downstream Wnt effectors, promoting stem and Paneth-like cell states while depleting differentiated enterocytes. Loss of just one Hmga1 allele within colon epithelium restrains tumorigenesis and Wnt signaling driven by mutant Apc and inflammatory microbiota. However, HMGA1 deficiency has minimal effects in colon epithelium under homeostatic conditions. In human colon cancer cells, HMGA1 directly induces ASCL2 by recruiting activating histone marks. Silencing HMGA1 disrupts oncogenic properties, whereas reexpression of ASCL2 partially rescues these phenotypes. Further, HMGA1 and ASCL2 are coexpressed and upregulated in human colorectal cancer. Together, our results establish HMGA1 as an epigenetic gatekeeper of Wnt signals and cell state under conditions of APC inactivation, illuminating HMGA1 as a potential therapeutic target in colon cancer.
Authors
Li Z. Luo, Jung-Hyun Kim, Iliana Herrera, Shaoguang Wu, Xinqun Wu, Seong-Sik Park, Juyoung Cho, Leslie Cope, Lingling Xian, Bailey E. West, Julian Calderon-Espinosa, Joseph Kim, Zanshé Thompson, Isha Maloo, Tatianna Larman, Karen L. Reddy, Ying Feng, Eric R. Fearon, Cynthia L. Sears, Linda Resar
Abstract
Metabolic reprogramming shapes tumor microenvironment (TME) and may lead to immunotherapy resistance in pancreatic ductal adenocarcinoma (PDAC). Elucidating the impact of pancreatic cancer cell metabolism in the TME is essential to therapeutic interventions. “Immune cold” PDAC is characterized by elevated lactate levels resulting from tumor cell metabolism, abundance of pro-tumor macrophages, and reduced cytotoxic T cell in the TME. Analysis of 18F-FDG uptake in patients showed that increased global protein lactylation in PDAC correlates with worse clinical outcomes in immunotherapy. Inhibition of lactate production in pancreatic tumors via glycolysis or mutant-KRAS inhibition reshaped the TME, thereby increasing their sensitivity to immune checkpoint blockade (ICB) therapy. In pancreatic tumor cells, lactate induces K63 lactylation of Endosulfine alpha (ENSA-K63la), a crucial step that triggers STAT3-CCL2 signaling. Consequently, elevated CCL2 secreted by tumor cells facilitates tumor-associated macrophage (TAM) recruitment to the TME. High levels of lactate also drive transcriptional reprogramming in TAMs via ENSA-STAT3 signaling, promoting an immunosuppressive environment. Targeting ENSA-K63la or CCL2 enhances the efficacy of ICB therapy in murine and humanized pancreatic tumor models. In conclusion, elevated lactylation reshapes the TME and promotes immunotherapy resistance in PDAC. Therapeutic approach targeting ENSA-K63la or CCL2 has shown promise in sensitizing pancreatic cancer immunotherapy.
Authors
Kang Sun, Xiaozhen Zhang, Jiatao Shi, Jinyan Huang, Sicheng Wang, Xiang Li, Haixiang Lin, Danyang Zhao, Mao Ye, Sirui Zhang, Li Qiu, Minqi Yang, Chuyang Liao, Lihong He, Mengyi Lao, Jinyuan Song, Na Lu, Yongtao Ji, Hanshen Yang, Lingyue Liu, Xinyuan Liu, Yan Chen, Shicheng Yao, Qianhe Xu, Jieru Lin, Yan Mao, Jingxin Zhou, Xiao Zhi, Ke Sun, Xiongbin Lu, Xueli Bai, Tingbo Liang
Abstract
Dysregulated eIF4E-dependent translation is a central driver of tumorigenesis and therapy resistance. eIF4E binding proteins (4E-BP1/2/3) are major negative regulators of eIF4E-dependent translation that are inactivated in tumors through inhibitory phosphorylation or downregulation. Previous studies have linked PP2A phosphatase(s) to activation of 4E-BP1. Here, we leveraged biased small molecule activators of PP2A (SMAPs) to explore the role of B56-PP2A(s) in 4E-BP regulation and the potential of B56-PP2A activation for restoring translational control in tumors. SMAP treatment promoted PP2A-dependent hypophosphorylation of 4E-BP1/2, supporting a role for B56-PP2As (e.g., B56α-PP2A) as 4E-BP phosphatases. Unexpectedly, SMAPs induced transcriptional upregulation of 4E-BP1 through a B56 PP2A→TFE3/TFEB→ATF4 axis. Cap-binding and co-immunoprecipitation assays showed that B56-PP2A(s) activation blocks assembly of the eIF4F translation initiation complex, and cap-dependent translation assays confirmed the translation inhibitory effects of SMAPs. Thus, B56-PP2A(s) orchestrate a translation repressive program involving transcriptional induction and activation of 4E-BP1. Notably, SMAPs promoted 4E-BP1-dependent apoptosis in tumor cells and potentiated 4E-BP1 function in the presence of ERK or mTOR inhibitors, agents that rely on inhibition of eIF4E-dependent translation for antitumor activity. These findings, combined with the ability of SMAPs to regulate 4E-BP1 in vivo, highlight the potential of PP2A activators for cancer therapy and overcoming therapy resistance.
Authors
Michelle A. Lum, Kayla A. Jonas, Shreya Parmar, Adrian R. Black, Caitlin M. O'Connor, Stephanie Dobersch, Naomi Yamamoto, Tess M. Robertson, Aidan Schutter, Miranda Giambi, Rita A. Avelar, Analisa DiFeo, Nicholas T. Woods, Sita Kugel, Goutham Narla, Jennifer D. Black
Abstract
BACKGROUND. B7-H3 or CD276 is notably overexpressed in various malignant tumor cells in humans, with extremely high expression rates. The development of a radiotracer that targets B7-H3 may provide a universal tumor-specific imaging agent and allow the noninvasive assessment of the whole-body distribution of B7-H3-expressing lesions. METHODS. We enhanced and optimized the structure of an affibody (ABY) that targets B7-H3 to create the radiolabeled radiotracer [68Ga]Ga-B7H3-BCH, and then, we conducted both foundational experiments and clinical translational studies. RESULTS. [68Ga]Ga-B7H3-BCH exhibited high affinity (Kd = 4.5 nM), and it was taken up in large amounts by B7-H3-transfected cells (A549CD276 and H1975CD276 cells); these phenomena were inhibited by unlabeled precursors. Moreover, PET imaging of multiple xenograft models revealed extensive [68Ga]Ga-B7H3-BCH uptake by tumors. In a clinical study including 20 patients with malignant tumors, the [68Ga]Ga-B7H3-BCH signal aggregated in both primary and metastatic lesions, surpassing 18F-FDG in overall diagnostic efficacy for tumors (85.0% vs 81.7%), including differentiated hepatocellular and metastatic gastric cancers. A strong correlation between B7-H3 expression and [68Ga]Ga-B7H3-BCH uptake in tumors was observed, and B7-H3 expression was detected with 84.38% sensitivity and 100% specificity when an SUVmax of 3.85 was set as the cutoff value. Additionally, B7-H3-specific PET imaging is expected to predict B7H3 expression levels in tumor cells, intratumoral stroma and peritumoral tissues. CONCLUSION. In summary, [68Ga]Ga-B7H3-BCH has potential for the noninvasive identification of B7H3 expression in systemic lesions in patients with malignant tumors. This agent has prospects for improving pretreatment evaluation, predicting therapeutic responses, and monitoring resistance to therapy in patients with malignancies. TRIAL REGISTRATION. ClinicalTrials.gov NCT06454955. FUNDING. This research was financially supported by the Natural Science Foundation of Beijing Municipality (No. 7242266), the National Natural Science Foundation of China (No. 82202201), and the Young Elite Scientists Sponsorship Program by CAST (No. YESS20220230).
Authors
Lei Xia, Yan Wu, Yanan Ren, Zhen Wang, Nina Zhou, Wenyuan Zhou, Lixin Zhou, Ling Jia, Chengxue He, Xiangxi Meng, Hua Zhu, Zhi Yang
Abstract
Stimulator of interferon genes (STING) agonists have been developed and tested in clinical trials for their antitumor activity. However, the specific cell population(s) responsible for such STING activation–induced antitumor immunity have not been completely understood. In this study, we demonstrated that endothelial STING expression was critical for STING agonist–induced antitumor activity. STING activation in endothelium promoted vessel normalization and CD8+ T cell infiltration — which required type I IFN (IFN-I) signaling— but not IFN-γ or CD4+ T cells. Rather than an upstream adaptor for inducing IFN-I signaling, STING acted downstream of interferon-α/β receptor (IFNAR) in endothelium for the JAK1-STAT signaling activation. Mechanistically, IFN-I stimulation induced JAK1-STING interaction and promoted JAK1 phosphorylation, which involved STING palmitoylation at the Cysteine 91 site but not its C-terminal tail (CTT) domain. Endothelial STING and JAK1 expression was significantly associated with immune cell infiltration in patients with cancer, and STING palmitoylation level correlated positively with CD8+ T cell infiltration around STING-positive blood vessels in tumor tissues from patients with melanoma. In summary, our findings uncover a previously unrecognized function of STING in regulating JAK1/STAT activation downstream of IFN-I stimulation and provide a new insight for future design and clinical application of STING agonists for cancer therapy.
Authors
Huanling Zhang, Zining Wang, Jiaxin Wu, Yong-Qiang Zheng, Qi Zhao, Shuai He, Hang Jiang, Chang Jiang, Tiantian Wang, Yongxiang Liu, Lei Cui, Hui Guo, Jiahong Yi, Huan Jin, Chunyuan Xie, Mengyun Li, Jiahui Li, Xiaojuan Wang, Liangping Xia, Xiao-Shi Zhang, Xiaojun Xia
Abstract
Mutations or homozygous deletions of MHC class II (MHC-II) genes are commonly found in B cell lymphomas that develop in immune-privileged sites and have been associated with patient survival. However, the mechanisms regulating MHC-II expression, particularly through genetic and epigenetic factors, are not yet fully understood. In this study, we identified a key signaling pathway involving the histone H2AK119 deubiquitinase BRCA1 associated protein 1 (BAP1), the interferon regulatory factor interferon regulatory factor 1 (IRF1), and the MHC-II transactivator class II transactivator (CIITA), which directly activates MHC-II gene expression. Disruption of the BAP1/IRF1/CIITA axis leads to a functional attenuation of MHC-II expression and MHC-II–dependent immune cell infiltration, leading to accelerated tumor growth in immunocompetent mice. Additionally, we demonstrated that pharmacological inhibition of polycomb repressive complex 1 (PRC1) — which deposits histone H2K119Ub and opposes BAP1 activity — can restore MHC-II gene expression in BAP1-deficient B cell lymphoma cells. These findings suggest that BAP1 may function as a tumor suppressor by regulating the tumor microenvironment and immune response. Our study also establishes the rationale for therapeutic strategies to restore tumor-specific MHC-II expression and enhance immunotherapy outcomes at epigenetic levels in B cell lymphoma treatment.
Authors
Te Zhang, Oguzhan Beytullahoglu, Rima Tulaiha, Amanda Luvisotto, Aileen Szczepanski, Natsumi Tsuboyama, Zibo Zhao, Lu Wang
Abstract
The biology centered around the TGF-beta type I receptor Activin Receptor-Like Kinase (ALK)1 (encoded by ACVRL1) has been almost exclusively based on its reported endothelial expression pattern since its first functional characterization more than two decades ago. Here, in efforts to better define the therapeutic context in which to use ALK1 inhibitors, we uncover a population of tumor-associated macrophages (TAMs) that, by virtue of their unanticipated Acvrl1 expression, are effector targets for adjuvant anti-angiogenic immunotherapy in mouse models of metastatic breast cancer. The combinatorial benefit depended on ALK1-mediated modulation of the differentiation potential of bone marrow-derived granulocyte-macrophage progenitors, the release of CD14+ monocytes into circulation, and their eventual extravasation. Notably, ACVRL1+ TAMs coincided with an immunosuppressive phenotype, and were over-represented in human cancers progressing on therapy. Accordingly, breast cancer patients with a prominent ACVRL1hi TAM signature exhibited a significantly shorter survival. In conclusion, we shed light on an unexpected multimodal regulation of tumorigenic phenotypes by ALK1 and demonstrate its utility as a target for anti-angiogenic immunotherapy.
Authors
Mehrnaz Safaee Talkhoncheh, Jonas Sjölund, Paulina Bolivar, Ewa Kurzejamska, Eugenia Cordero, Teia Vallès Pagès, Sara Larsson, Sophie Lehn, Gustav Frimannsson, Viktor Ingesson, Sebastian Braun, Jessica Pantaleo, Clara Oudenaarden, Martin Lauss, R. Scott Pearsall, Göran B. Jönsson, Charlotte Rolny, Matteo Bocci, Kristian Pietras
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
Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)