Project description:To understand how KMT2D impacts anti-viral CD4 T-cell responses, we performed scRNA-seq on WT and KMT2D-/- effector CD4 T-cells obtained from LCMV Armstrong infected mice
Project description:Somatic mutations in various epigenetic regulators, including histone methyltransferases KMT2C and KMT2D, have emerged as important cancer-driving events. However, the mechanism of action and therapeutic vulnerability imparted by these mutations remain poorly understood. We identified KMT2D and 8 other epigenetic regulators as potential suppressors to melanoma initiation through an in vivo pooled epigenome-focused RNAi screen. Loss of KMT2D, which exhibits somatic mutations in human melanoma and other cancers, drastically enhanced melanoma progression in xenograft models and a BRAFV600E-driven genetically engineered mouse model of melanoma. Epigenome profiling of 6 histone marks and chromatin state alterations showed substantial reprogramming of H3K4me1- and H3K27ac-marked active enhancer states in KMT2D mutant tumors. Energy metabolic pathways such as glycolysis, OxPhos and TCA/electron transport showed high degree of deregulation which was confirmed with metabolic profiling. Pharmacological abrogation of glycolysis led to reduced proliferation and tumorigenesis preferentially in KMT2D mutant cells. Mechanistically, we find that enhancer loss at IGFBPs increases IGF signaling and downstream AKT phosphorylation that leads to upregulation of metabolic pathways rendering KMT2D mutant cells dependent on these energy metabolism pathways for their higher growth potential. Overall, we present evidence that KMT2D mutations promote tumorigenesis by reprogramming energy metabolism pathways through enhancer reprogramming.
Project description:We conducted genome wide transcription profiling by RNA-seq in proliferating neuronal progenitors after purifying EdU+ nuclei from micro-dissected DG of adult wild-type and KMT2D-deficient mice (Kmt2d +/Bgeo)
Project description:Somatic mutations in various epigenetic regulators, including histone methyltransferases KMT2C and KMT2D, have emerged as important cancer-driving events. However, the mechanism of action and therapeutic vulnerability imparted by these mutations remain poorly understood. We identified KMT2D and 8 other epigenetic regulators as potential suppressors to melanoma initiation through an in vivo pooled epigenome-focused RNAi screen. Loss of KMT2D, which exhibits somatic mutations in human melanoma and other cancers, drastically enhanced melanoma progression in xenograft models and a BRAFV600E-driven genetically engineered mouse model of melanoma. Epigenome profiling of 6 histone marks and chromatin state alterations showed substantial reprogramming of H3K4me1- and H3K27ac-marked active enhancer states in KMT2D mutant tumors. Energy metabolic pathways such as glycolysis, OxPhos and TCA/electron transport showed high degree of deregulation which was confirmed with metabolic profiling. Pharmacological abrogation of glycolysis led to reduced proliferation and tumorigenesis preferentially in KMT2D mutant cells. Mechanistically, we find that enhancer loss at IGFBPs increases IGF signaling and downstream AKT phosphorylation that leads to upregulation of metabolic pathways rendering KMT2D mutant cells dependent on these energy metabolism pathways for their higher growth potential. Overall, we present evidence that KMT2D mutations promote tumorigenesis by reprogramming energy metabolism pathways through enhancer reprogramming.
Project description:The histone-3 lysine-4 methyltransferase KMT2D is frequently mutated in human cancers. However, knowledge of its role in the initiation and maintenance of acute myeloid leukemia (AML) is incomplete. Here, we show that KMT2D is generally downregulated in human AML. Using shRNA and CRISPR/Cas9 technologies, we show that Kmt2d loss, by cooperating with Trp53 and Nf1 loss, promoted mouse acute myeloid leukemogenesis through a differentiation block of hematopoietic stem and progenitor cells. Furthermore, using a doxycycline-induced shRNA system, we show that restoring Kmt2d impairs AML maintenance. Multi-omics analyses of Kmt2d-deficient and -restored AML cells showed that Kmt2d, via histone methyltransferase activity and chromatin remodeling, epigenetically regulates the expression of genes controlling hematopoietic stem cell differentiation. Lastly, we showed that 3-Deazaneplanocin A, a histone methyltransferase EZH2 inhibitor, could specifically repress Kmt2d-deficient AML cell growth and reverse pro-leukemia programs. Thus, our study indicate Kmt2d is a tumor suppressor, whose downregulation promotes AML development through differentiation blockage.