KMT2C methyltransferase domain regulated INK4A expression suppresses prostate cancer metastasis
Ontology highlight
ABSTRACT: Frequent truncating mutations of the histone lysine N‑methyltransferase KMT2C have been detected by whole exome sequencing studies in various cancers, including malignancies of the prostate. However, the biological consequences of these alterations in prostate cancer have not yet been elucidated. To investigate the functional impact of these mutations we deleted the C-terminal catalytic core motif of KMT2C specifically in the prostate epithelium of mice. We show here that impaired KMT2C methyltransferase activity drives proliferation and, when combined with loss of the tumour suppressor PTEN, triggers metastatic dissemination and reduces life expectancy. In our model system and human prostate cancer samples we show that KMT2C-mutated tumours activate the proliferative MYC signalling axis and fail to express the oncogene-induced cell cycle repressor p16INK4A. In addition, we observe a striking reduction in disease-free survival of patients with KMT2C-mutated prostate cancer. Thus, we identify truncated KMT2C as a driver of aggressive prostate cancer.
Project description:KMT2C and KMT2D are two of the most frequently mutated genes in histologically normal human bladder urothelium. In this study, we sought to model Kmt2c/d LOF mutations and investigate the biological mechanism of Kmt2c/d LOF mutations in bladder cancer development.
Project description:Prostate cancer (PCa) is a leading cause of male morbidity and mortality. Epigenetic modifier abnormalities are becoming a driving event in prostate cancer (PCa). The specific role of KMT2C, a histone methyltransferase that is frequently aberrant in various tumors, is poorly understood in PCa. This study aimed to reveal the potential carcinogenic role of KMT2C in PCa. Herein we confirmed the KMT2C overexpression in PCa, at transcript and protein level. Knockdown KMT2C in VCaP and LNCaP cells attenuated malignant phenotype, suppressing cell viability, clony, and migration. Consistently, stable KMT2C depletion effectively decreases tumor growth by about 70% in vivo. Mechanically, the results suggest that CLDN8 and ITGAV are two key downstream genes of KMT2C.
Project description:KMT2C and KMT2D are two of the frequently mutated epigenetic modifiers in urothelial cancer. To compare the histone post-translational modification with Kmt2c/d loss, we performed mass spectrometry analysis of histones from Kmt2c/d WT and dKO urothelial cells.
Project description:The histone 3 lysine 4 (H3K4) monomethylase KMT2C is mutated across several cancer types, however the effects of mutations on epigenome organization, gene expression and cell growth are not clear. To study effects of KMT2C expression in CRC cells we restored one allele to wild type KMT2C in the two CRC cell lines RKO and HCT116, which both are homozygous KMT2C c.8390delA mutant, by gene editing. RNA sequencing was performed to profile gene expression when KMT2C was restored in RKO and HCT116 cells.
Project description:Small cell lung cancer (SCLC) is notorious for its early and frequent metastases, which contribute to it as a recalcitrant malignancy. To understand the molecular mechanisms underlying SCLC metastasis, we generated SCLC mouse models with orthotopically transplanted genome-edited lung organoids and performed multi-omics analyses. We found that loss of KMT2C, an H3K4 methyltransferase frequently mutated in extensive stage SCLC, promoted multiple-organ metastases in mice. Metastatic and KMT2C deficient SCLC displayed both histone and DNA hypomethylation. Mechanistically, KMT2C directly regulated the expression of DNMT3A, a de novo DNA methyltransferase, through histone methylation. Forced DNMT3A expression restrained metastasis of KMT2C deficient SCLC through repressing metastasis promoting MEIS/HOX genes. Further, S-(5’-Adenosyl)-L-methionine, the common cofactor of histone and DNA methyltransferases, inhibited SCLC metastasis. Thus, our study revealed a concerted epigenetic reprogramming of KMT2C and DNMT3A-mediated histone and DNA hypomethylation underlying SCLC metastasis, which suggested a new epigenetic therapeutic vulnerability.
Project description:The histone 3 lysine 4 (H3K4) monomethylase KMT2C is mutated across several cancer types, however the effects of mutations on epigenome organization, gene expression and cell growth are not clear. To study effects of KMT2C expression in CRC cells we restored one allele to wild type KMT2C in the two CRC cell lines RKO and HCT116, which both are homozygous KMT2C c.8390delA mutant. Chromatin was analysed by ChIP-sequencing using the Diagenode iDeal ChIP-seq kit for Histones and the H3K4me1 specific antibody (Abcam ab8895).
Project description:KMT2C and KMT2D are two of the most frequently mutated genes in bladder cancer and in histologically normal urothelium. In this study, we developed mouse models to investigate the molecular mechanism of Kmt2c/d loss in urothelial tumorigenesis.
Project description:KMT2C and KMT2D are two of the most frequently mutated genes in bladder cancer and in histologically normal urothelium. In this study, we developed mouse models to investigate the molecular mechanism of Kmt2c/d loss in urothelial tumorigenesis.
Project description:Double-negative prostate cancer (DNPC), characterized by AR-null tumors with inherent plasticity, predominantly arises following androgen deprivation therapy (ADT). However, the cellular origin, signaling hierarchy, and treatment strategies for this lethal subtype remain unclear. Here, we demonstrate that the loss of KMT2C, a histone H3K4 methylation transferase preferentially mutated in the DNPC subtype, collaborates with ADT to drive the transformation of luminal tumors into DNPC. Our findings reveal that DNPC arises from the transdifferentiation of luminal cells rather than basal cell expansion. This transdifferentiation is orchestrated by the upregulation of ΔNp63, induced by the dual inactivation of AR and KMT2C. Treatment with antiandrogens facilitates KMT2C binding to the enhancers of a subset of AR-regulated genes, compensating for AR inactivation to preserve the luminal identity. Among these, ARPP2 maintains its expression via KMT2C-dependent enhancer-promoter communication following AR inactivation. Consequently, KMT2C inactivation reduces ARPP2 expression, leading to p65-dependent upregulation of ΔNp63 and subsequent DNPC development. In our DNPC model, we identified a selective reinstatement of fatty acid synthesis, facilitated by the ΔNp63-dependent SREBP1 transcriptome. This sustains DNPC growth through intensified HRAS palmitoylation and activation of the RAS-MAPK signaling pathway. Our findings underscore the role of KMT2C as an epigenetic checkpoint in restraining DNPC transdifferentiation. This highlights an elevated risk for KMT2C-mutated patients receiving ADT and underscores the potential therapeutic targeting of fatty acid synthesis against DNPC.