Project description:Discarded live tumor tissue from a metastatic focus in the patientM-bM-^@M-^Ys lung was collected under institutional review board approval through the NUT midline carcinoma registry (www.NMCRegistry.org). From this tissue the first known NUT-variant cell line, 1221, was established. To determine the putative partner gene to NUT, we performed comprehensive RNA-sequencing on RNA purified from 1221. We identified an in-frame transcript fusing the 5M-bM-^@M-^Y coding sequence of NSD3 (exons 1-7) to exons 2-7 of NUT. Expression of the NSD3-NUT fusion oncoprotein was verified by immunobloting with an antibody to NUT, revealing an approximately 200kDa band that is similar in size to BRD3-NUT, but smaller than BRD4-NUT Identification of a NUT fusion partner using RNA extracted from live cultured 1221 cell line derived from a lung metastasis from the index case of a 13 year old female with NUT-positive NMC.
Project description:Knockdown of the oncogene, BRD4-NUT, in a rare cancer, termed NUTmidline carcinoma (NMC), results in morphologic features consistent with squamous differentiation. Treatment with the HDAC-inhibitor, TSA, appears to cause the same phenotype. Here, we use gene expression profiling to compare the changes in gene expression following BRD4-NUT knockdown and TSA treatment. RNA was extracted from two BRD4-NUT-expressing NMC cell lines, PER-403 and TC-797, 24h following siRNA knockdown versus control in duplicate. RNA was extracted from two BRD4-NUT-expressing NMC cell lines, PER-403 and TC-797, 24h following treatment with TSA versus etoh control in triplicate
Project description:Discarded live tumor tissue from a metastatic focus in the patient’s lung was collected under institutional review board approval through the NUT midline carcinoma registry (www.NMCRegistry.org). From this tissue the first known NUT-variant cell line, 1221, was established. To determine the putative partner gene to NUT, we performed comprehensive RNA-sequencing on RNA purified from 1221. We identified an in-frame transcript fusing the 5’ coding sequence of NSD3 (exons 1-7) to exons 2-7 of NUT. Expression of the NSD3-NUT fusion oncoprotein was verified by immunobloting with an antibody to NUT, revealing an approximately 200kDa band that is similar in size to BRD3-NUT, but smaller than BRD4-NUT
Project description:Knockdown of the oncogene, BRD4-NUT, in a rare cancer, termed NUTmidline carcinoma (NMC), results in morphologic features consistent with squamous differentiation. Treatment with the HDAC-inhibitor, TSA, appears to cause the same phenotype. Here, we use gene expression profiling to compare the changes in gene expression following BRD4-NUT knockdown and TSA treatment.
Project description:NUT carcinoma (NC) is an aggressive cancer with no effective treatment. About 70% of NUT carcinoma is associated with chromosome translocation events that lead to the formation of a BRD4::NUTM1 fusion gene. Because the BRD4::NUTM1 gene is unequivocally cytotoxic when ectopically expressed in cell lines, questions remain on whether the fusion gene can initiate NC. Here, we report the first genetically engineered mouse model (GEMM) for NUT carcinoma that recapitulates the t(15;19) chromosome translocation in mice. We demonstrated that the mouse t(2;17) syntenic chromosome translocation, forming the Brd4::Nutm1 fusion gene, could induce aggressive carcinomas in mice. The tumors present histopathological and molecular features similar to human NC, with an enrichment of undifferentiated cells. Similar to the reports of human NC incidence, Brd4::Nutm1 can induce NC from a broad range of tissues with a strong phenotypical variability. The consistent induction of poorly differentiated carcinoma demonstrated a strong reprogramming activity of BRD4::NUTM1. The new mouse model provided a critical preclinical model for NC that will lead to better understanding and therapy development for NC.
Project description:To determine mechanisms of synergy between EZH2 and BRD4-NUT, we treated NUT carcinoma cell lines with EZH2 inhibitor, tazemetostat, and/or BET bromodomain inhibitors (ABBV075 pan-BET inhibitor or ABBV744 BD2-selective inhibitor). We then performed gene expression profiling analysis using data obtained from RNA-seq of 2 different NUT carcinoma cell lines at two time points, 6h and 96h.
Project description:To investigate the mechanism that drives dramatic mistargeting of active chromatin in NUT-midline carcinoma, we have identified protein interactions unique to the BRD4-NUT fusion oncoprotein compared to wild type BRD4. Using crosslinking, affinity purification, and mass spectrometry, we identify the p300 acetyltransferase as ectopically associated with BRD4 through the NUT fusion in both NMC and non-NMC cell types. We also identify ZNF532 among a number of candidates uniquely associated with BRD4-NUT in NMC patient cells but not present in 293T cells. p300 and ZNF532 are both implicated in feed-forward regulatory loops leading to propagation of the oncogenic regulatory complex in BRD4-NUT patient cells. Extending our biochemical findings, we independently identified a novel ZNF532-NUT translocation fusion in a newly diagnosed NMC patient. ChIP-seq of key players: NUT, ZNF532, BRD4, p300, and anti-H3K27ac, reveals the formation of ZNF532-NUT-associated hyperacetylated megadomains, distinctly localized, but otherwise analogous to those found in BRD4-NUT patient cells. Our results support a model in which NMC is caused by a cascade of misregulation that is initiated by ectopic protein-protein interactions on chromatin between NUT and several distinct, but interacting, components of BRD4 regulatory complexes.
Project description:NUT carcinoma (NC) is a highly aggressive subtype of squamous carcinoma driven by the BRD4-NUT fusion oncoprotein. Closely resembling human NC (hNC), GEMM tumors (mNC) are poorly differentiated squamous carcinomas that express high levels of MYC and metastasize to organs (liver, lung) and regional lymph nodes. Two GEMM-derived cell lines were developed whose transcriptomic and epigenetic landscapes, characterized by RNAseq and CUT&RUN, show striking overlap with those of primary GEMM tumors. As in hNC, BRD4-NUT functions to block differentiation and maintain growth of mNC, as evidenced by BRD4-NUT knockdown and treatment of mNC cell lines with BET bromodomain inhibitors (BETi). Mechanistically, GEMM primary tumor and cell lines form very large H3K27ac-enriched super-enhancers that are unique to hNC, termed megadomains, that are invariably associated with key hNC-defining transcriptional oncogenic targets, Myc and Trp63.
Project description:NUT carcinoma (NC) is an aggressive cancer with no effective treatment. About 70% of NUT carcinoma is associated with chromosome translocation events that lead to the formation of a BRD4::NUTM1 fusion gene. Because the BRD4::NUTM1 gene is unequivocally cytotoxic when ectopically expressed in cell lines, questions remain on whether the fusion gene can initiate NC. Here, we report the first genetically engineered mouse model (GEMM) for NUT carcinoma that recapitulates the t(15;19) chromosome translocation in mice. We demonstrated that the mouse t(2;17) syntenic chromosome translocation, forming the Brd4::Nutm1 fusion gene, could induce aggressive carcinomas in mice. The tumors present histopathological and molecular features similar to human NC, with an enrichment of undifferentiated cells. Similar to the reports of human NC incidence, Brd4::Nutm1 can induce NC from a broad range of tissues with a strong phenotypical variability. The consistent induction of poorly differentiated carcinoma demonstrated a strong reprogramming activity of BRD4::NUTM1. The new mouse model provided a critical preclinical model for NC that will lead to better understanding and therapy development for NC.