ABSTRACT: Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, with 5-year survival of ~50%. Genomic profiling studies have identified important somatic mutations in this disease which presents an opportunity for precision medicine. We demonstrate that KMT2D, a histone methyltransferase harbors somatic mutations in ~17% of HNSCC and is associated with 2-year recurrence in TCGA data. Consistent with algorithmic prediction of bring a driver tumor-suppressor event, its loss results in larger oral tumors in immune-proficient orthotopic models. Mechanistically, we find that KMT2D knockdown or KMT2D mutation causes loss of H3K4me1-marked enhancers harboring IRF7/9 binding sites, which is known to regulate interferon signaling. Indeed, KMT2D loss in human and murine cell lines deregulated transcriptional levels of cytokine expression and impacted numerous immune signaling pathways, including interferon signaling. Consistently, Kmt2d knockdown in murine tumors exhibited decrease in IFN-producing effector T cells and an increase in T-cells with an exhausted phenotype. Epistasis experiments showed that exogenous treatment with IFN abrogated the increased tumor growth in Kmt2d-deficient oral tumors. Together, these results support the role of KMT2D as a tumor suppressor in HNSCC that regulates the tumor microenvironment by modulating H3K4me1-marked enhancers controlling interferon signaling.
Project description:Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, with 5-year survival of ~50%. Genomic profiling studies have identified important somatic mutations in this disease which presents an opportunity for precision medicine. We demonstrate that KMT2D, a histone methyltransferase harbors somatic mutations in ~17% of HNSCC and is associated with 2-year recurrence in TCGA data. Consistent with algorithmic prediction of bring a driver tumor-suppressor event, its loss results in larger oral tumors in immune-proficient orthotopic models. Mechanistically, we find that KMT2D knockdown or KMT2D mutation causes loss of H3K4me1-marked enhancers harboring IRF7/9 binding sites, which is known to regulate interferon signaling. Indeed, KMT2D loss in human and murine cell lines deregulated transcriptional levels of cytokine expression and impacted numerous immune signaling pathways, including interferon signaling. Consistently, Kmt2d knockdown in murine tumors exhibited decrease in IFN-producing effector T cells and an increase in T-cells with an exhausted phenotype. Epistasis experiments showed that exogenous treatment with IFNabrogated the increased tumor growth in Kmt2d-deficient oral tumors. Together, these results support the role of KMT2D as a tumor suppressor in HNSCC that regulates the tumor microenvironment by modulating H3K4me1-marked enhancers controlling interferon signaling.
Project description:Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, with 5-year survival of ~50%. Genomic profiling studies have identified important somatic mutations in this disease which presents an opportunity for precision medicine. We demonstrate that KMT2D, a histone methyltransferase harbors somatic mutations in ~17% of HNSCC and is associated with 2-year recurrence in TCGA data. Consistent with algorithmic prediction of bring a driver tumor-suppressor event, its loss results in larger oral tumors in immune-proficient orthotopic models. Mechanistically, we find that KMT2D knockdown or KMT2D mutation causes loss of H3K4me1-marked enhancers harboring IRF7/9 binding sites, which is known to regulate interferon signaling. Indeed, KMT2D loss in human and murine cell lines deregulated transcriptional levels of cytokine expression and impacted numerous immune signaling pathways, including interferon signaling. Consistently, Kmt2d knockdown in murine tumors exhibited decrease in IFN-producing effector T cells and an increase in T-cells with an exhausted phenotype. Epistasis experiments showed that exogenous treatment with IFNabrogated the increased tumor growth in Kmt2d-deficient oral tumors. Together, these results support the role of KMT2D as a tumor suppressor in HNSCC that regulates the tumor microenvironment by modulating H3K4me1-marked enhancers controlling interferon signaling.
Project description:Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, with 5-year survival of ~50%. Genomic profiling studies have identified important somatic mutations in this disease which presents an opportunity for precision medicine. We demonstrate that KMT2D, a histone methyltransferase harbors somatic mutations in ~17% of HNSCC and is associated with 2-year recurrence in TCGA data. Consistent with algorithmic prediction of bring a driver tumor-suppressor event, its loss results in larger oral tumors in immune-proficient orthotopic models. Mechanistically, we find that KMT2D knockdown or KMT2D mutation causes loss of H3K4me1-marked enhancers harboring IRF7/9 binding sites, which is known to regulate interferon signaling. Indeed, KMT2D loss in human and murine cell lines deregulated transcriptional levels of cytokine expression and impacted numerous immune signaling pathways, including interferon signaling. Consistently, Kmt2d knockdown in murine tumors exhibited decrease in IFN-producing effector T cells and an increase in T-cells with an exhausted phenotype. Epistasis experiments showed that exogenous treatment with IFNabrogated the increased tumor growth in Kmt2d-deficient oral tumors. Together, these results support the role of KMT2D as a tumor suppressor in HNSCC that regulates the tumor microenvironment by modulating H3K4me1-marked enhancers controlling interferon signaling.
Project description:Histone H3 lysine (H3K4) methyltransferase KMT2D is a key regulator of gene expression, mainly through promoting H3K4 methylation and activating enhancers, and plays critical roles in development, differentiation, metabolism, and tumor suppression. Here, our study showed that KMT2D was recruited to the enhancer regions of several Fanconi anemia (FA) pathway genes, such as ATR, FANCM, REV3L, and TOP3A, in response to glucose deprivation. Notably, KMT2D loss led to significant impairment of promoter/enhancer signals, as evidenced by decreased H3K4me1, H3K4me3, and H3K27ac signals, on several FA pathway genes. Our ChIP-Seq results demonstrated that the inactivation of promoters/enhancers due to KMT2D loss is a key contributor to the downregulation of FA pathway genes in glucose-deprived KMT2D-deficient HNSCC.
Project description:Histone H3 lysine (H3K4) methyltransferase KMT2D is a key regulator of gene expression, mainly through promoting H3K4 methylation and activating enhancers, and plays critical roles in development, differentiation, metabolism, and tumor suppression. To investigate the mechanisms by which KMT2D loss promotes HNSCC and to identify potential therapeutic targets, we generated KMT2D wild-type (KMT2D-WT) and KMT2D knock-out (KMT2D-KO) SCC23 HNSCC cells and performed RNA-seq under different glucose conditions.
Project description:To identify the activated tyrosine kinase signaling pathways in HNSCC, we carried out phosphotyrosine profiling using a panel of HNSCC cell lines compared to a normal oral keratinocyte. A total of 61 unique phosphosites were identified across these cell lines. Dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A) was one of the kinases hyperphosphorylated at Y321 in all the HNSCC cell lines compared to the normal oral cell line OKF6/TERT1. Inhibition of DYRK1A using its specific siRNA and inhibitor resulted in a decrease in the invasion and colony formation ability of the HNSCC cell lines. Further, the treatment of mice bearing HNSCC xenograft tumors with DYRK1A inhibitor (harmine) showed regression of tumor growth. Our results demonstrate that DYRK1A could be a novel therapeutic target in HNSCC.
Project description:KMT2D is a histone methyltransferase for catalyzing the monomethylation of H3K4. The H3K4me1 is prominent on active enhancers and participates in gene expression regulation. Loss of KMT2D in cancer has been approved to impact on a set of gene expression by the reduction of H3K4me1 level. To identify the direct target of KMT2D in prostate cancer, we performed H3K4me1 ChIP-seq with KMT2D knockdown and control PC-3 cells.
Project description:Define and compare H3K4me2 enrichment in murine B220 cells transduced with empty vector (ct) or KMT2D-shRNA. Compare gene expression by RNAseq in murine B220 cells transduced with empty vector (ct) or KMT2D-shRNA. Using H3K4me1/2 ChIPseq and RNAseq we profiled murine B220 purified cells from tumors transduced with EV (n=3) or KMT2D-shRNA (n=3).
Project description:Immune checkpoint blockers (ICBs) targeting programmed death 1(PD-1) are considered effective first-line therapy against PD-1 ligand (PD-L1)-expressing head and neck squamous cell carcinoma (HNSCC). However, associated changes in tumor microenvironment (TME) and mechanisms remain elusive. Oral tumors in C57/BL6 mice were induced by administering 7,12-dimethylbenzanthracene into the buccal mucosa. Single-cell suspension was isolated from tumor tissue; proliferating cells were injected subcutaneously into the left flank of mice to establish Ajou Oral Cancer (AOC) cell lines. Subsequently, a syngeneic PD-L1-expressing HNSCC xenograft model was developed by injecting AOC cells into the buccal or tongue area. The model recapitulated human HNSCC molecular features and showed reliable in vivo tumorigenicity with significant PD-L1 expression. ICB monotherapy induced global changes in TME, including vascular normalization. Furthermore, the anti-tumor effect of ICB monotherapy was superior to those of other therapeutic agents, including cisplatin and anti-vascular endothelial growth factor receptor 2 inhibitors. The ICB-induced anti-tumorigenicity and TME normalization were alleviated by blocking the Type I interferon pathway.In summary, ICB monotherapy is sufficient to induce TME normalization in the syngeneic model; the Type-I interferon pathway is indispensable in realizing ICB effects. Furthermore, these results explain the underlying mechanism of the efficacy of ICB monotherapy against HNSCC expressing PD-L1 in the KEYNOTE-048 trial. This model can assist future research on HNSCC immunotherapy.
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.