Dataset Information

CHMP5-Mediated Transcriptional Regulation of T-Cell Acute Lymphoblastic Leukemia (Murine RNAseq)

ABSTRACT: Oncogene activity rewires cellular transcription to create new transcriptional networks which cancer cells become addicted to through mechanisms that remain unresolved. Using human and mouse models of T-cell acute lymphoblastic leukemia (T-ALL), we identified an essential requirement of the endosomal sorting complex required for transport (ESCRT) protein CHMP5 in enabling the T-ALL transcriptional program. Loss of CHMP5 impaired recruitment of the bromodomain transcriptional coactivator BRD4 to enhancer and super-enhancers which caused RNA polymerase II stalling, resulting in severe downregulation of key pro-leukemogenic genes, including MYC and MYC-target genes. Mechanistically, CHMP5 facilitated BRD4 interaction with the histone acetyl transferase p300 to promote H3K27 acetylation at pro-T-ALL gene regulatory elements. Validating its importance to T-cell leukemogenesis, CHMP5-deficiency mitigated chemoresistance in human T-ALL cells and abrogated T-ALL initiation by oncogenic NOTCH1 in vivo. Collectively, our results uncover an unexpected transcriptional activity of CHMP5 that is essential for T-ALL pathogenesis.

ORGANISM(S): Mus musculus

PROVIDER: GSE244199 | GEO | 2024/02/26

REPOSITORIES: GEO

ACCESS DATA

Shared Molecules

Only show the datasets with similarity scores above: 0.5

Threshold

0.5

Similar Datasets

Project description:The histone acetyl-reader BRD4 is an important regulator of chromatin structure and transcription, yet factors modulating its activity have remained elusive. Here we describe two complementary screens for genetic and physical interactors of BRD4, which converge on the folate pathway enzyme MTHFD1. We show that a fraction of MTHFD1 resides in the nucleus, where it is recruited to distinct genomic loci by direct interaction with BRD4. Inhibition of either BRD4 or MTHFD1 results in similar changes in nuclear metabolite composition and gene expression, and pharmacologic inhibitors of the two pathways synergize to impair cancer cell viability in vitro and in vivo. Our finding that MTHFD1 and other metabolic enzymes are chromatin-associated suggests a direct role for nuclear metabolism in the control of gene expression. BRD4 is an important chromatin regulator with roles in gene regulation, DNA damage, cell proliferation and cancer progression1-4. The protein is recruited to distinct genomic loci by the interaction of its tandem bromodomains with acetylated lysines on histones and other nuclear proteins5. There, BRD4 acts as a transcriptional activator by P-TEFb-mediated stimulation of transcriptional elongation6. The activating function of BRD4 on key driver oncogenes like MYC have made this epigenetic enzyme an important therapeutic target in both BRD4 translocated and BRD4 wild-type cancers3,7-12, and at least seven bromodomain inhibitors have reached the clinical stage13. Genome-wide studies have identified the role of BRD4-induced epigenetic heterogeneity in cancer cell resistance14, and factors defining BRD4 inhibitor response15,16. However, despite its clinical importance and the broad role of BRD4 in chromatin organization, surprisingly little is known about factors that are directly required for BRD4 function. To systematically expand the list of known BRD4 interactors5 and to characterize proteins directly required for BRD4 function, we developed a strategy of two complementary screens for genetic and physical partners of BRD4. The two approaches converge on a single factor, methylenetetrahydrofolate dehydrogenase 1 (MTHFD1). Our description of a transcriptional role for this C-1-tetrahydrofolate synthase highlights a direct connection between nuclear folate metabolism and cancer regulation.