biostudies-literatureDurall RTDana-Farber Cancer InstituteAlex&apos;s Lemonade Stand Foundation for Childhood CancerSamuel Waxman Cancer Research FoundationFondation BertarelliNHLBI NIH HHSNational Cancer InstituteNCI NIH HHSNational Institutes of HealthGarron Family Cancer CentreCancer Prevention and Research Institute of TexasNIH HHS3846-3860https://www.ebi.ac.uk/biostudies/studies/S-EPMC10690098biostudies-literatureUnknown83(23)NUT carcinoma (NC) is an aggressive squamous carcinoma defined by the BRD4-NUT fusion oncoprotein. Routinely effective systemic treatments are unavailable for most NC patients. The lack of an adequate animal model precludes identifying and leveraging cell-extrinsic factors therapeutically in NC. Here, we created a genetically engineered mouse model (GEMM) of NC that forms a Brd4::NUTM1 fusion gene upon tamoxifen induction of Sox2-driven Cre. The model displayed complete disease penetrance, with tumors arising from the squamous epithelium weeks after induction and all mice succumbing to the disease shortly thereafter. Closely resembling human NC (hNC), GEMM tumors (mNC) were poorly differentiated squamous carcinomas with high expression of MYC that metastasized to solid organs and regional lymph nodes. Two GEMM-derived cell lines were developed whose transcriptomic and epigenetic landscapes harbored key features of primary GEMM tumors. Importantly, GEMM tumor and cell line transcriptomes co-classified with those of human NC. BRD4-NUT also blocked differentiation and maintained the growth of mNC as in hNC. Mechanistically, GEMM primary tumors and cell lines formed large histone H3K27ac-enriched domains, termed megadomains, that were invariably associated with the expression of key NC-defining proto-oncogenes, Myc and Trp63. Small-molecule BET bromodomain inhibition (BETi) of mNC induced differentiation and growth arrest and prolonged survival of NC GEMMs, as it does in hNC models. Overall, tumor formation in the NC GEMM is definitive evidence that BRD4-NUT alone can potently drive the malignant transformation of squamous progenitor cells into NC.<h4>Significance</h4>The development of an immunocompetent model of NUT carcinoma that closely mimics the human disease provides a valuable global resource for mechanistic and preclinical studies to improve treatment of this incurable disease.Cancer researchThe BRD4-NUT Fusion Alone Drives Malignant Transformation of NUT Carcinoma.PMC10690098OD024587R01 CA124633RR21008212463322-25794157174R01 HL157174285308R01 CA279391DP5 OD024587R01 CA285308Eagen KPDurall RTBertaux FHuang JDavidson SSotirakis EKeskin DBGokhale PCWojenski LNash JOFrench CAShapiro GIBallester PLDubus VShlien ALeeper BAHuang YLuo JWu CJfalseThe BRD4-NUT Fusion Alone Drives Malignant Transformation of NUT Carcinoma.NUT carcinoma (NC) is an aggressive squamous carcinoma defined by the BRD4-NUT fusion oncoprotein. Routinely effective systemic treatments are unavailable for most NC patients. The lack of an adequate animal model precludes identifying and leveraging cell-extrinsic factors therapeutically in NC. Here, we created a genetically engineered mouse model (GEMM) of NC that forms a Brd4::NUTM1 fusion gene upon tamoxifen induction of Sox2-driven Cre. The model displayed complete disease penetrance, with tumors arising from the squamous epithelium weeks after induction and all mice succumbing to the disease shortly thereafter. Closely resembling human NC (hNC), GEMM tumors (mNC) were poorly differentiated squamous carcinomas with high expression of MYC that metastasized to solid organs and regional lymph nodes. Two GEMM-derived cell lines were developed whose transcriptomic and epigenetic landscapes harbored key features of primary GEMM tumors. Importantly, GEMM tumor and cell line transcriptomes co-classified with those of human NC. BRD4-NUT also blocked differentiation and maintained the growth of mNC as in hNC. Mechanistically, GEMM primary tumors and cell lines formed large histone H3K27ac-enriched domains, termed megadomains, that were invariably associated with the expression of key NC-defining proto-oncogenes, Myc and Trp63. Small-molecule BET bromodomain inhibition (BETi) of mNC induced differentiation and growth arrest and prolonged survival of NC GEMMs, as it does in hNC models. Overall, tumor formation in the NC GEMM is definitive evidence that BRD4-NUT alone can potently drive the malignant transformation of squamous progenitor cells into NC.<h4>Significance</h4>The development of an immunocompetent model of NUT carcinoma that closely mimics the human disease provides a valuable global resource for mechanistic and preclinical studies to improve treatment of this incurable disease.2023-01-01T00:00:00Z2023 Dec2026-05-28T21:34:58.427Z2025-04-19T20:22:05.328ZS-EPMC106900983781923610.1158/0008-5472.CAN-23-2545