CRISPR-GEMM pooled mutagenic screening identifies KMT2D as a major modulator of immune checkpoint blockade (ATAC-Seq)
Ontology highlight
ABSTRACT: Immune checkpoint blockade (ICB) has shown remarkable clinical efficacy across multiple cancer types. However, only a fraction of patients respond to ICB. Here, we performed pooled mutagenic screening with CRISPR-mediated genetically engineered mouse models (CRISPR-GEMMs) in ICB settings, and identified KMT2D as a major modulator of ICB response across multiple cancer types. Kmt2d encodes a histone H3K4 methyltransferase and is among the most frequently mutated genes in cancer patients. Kmt2d loss led to increased DNA damage and mutation burden, chromatin remodeling, intron retention, and activation of transposable elements. Additionally, Kmt2d-deficient cells exhibit increased protein turnover and IFN-γ-stimulated antigen presentation. In turn, Kmt2d-mutant tumors in both mouse and human are characterized by increased immune infiltration. These data demonstrate that KMT2D deficiency sensitizes tumors to ICB by augmenting tumor immunogenicity, highlighting the power of CRISPR-GEMMs for interrogating complex molecular landscapes in immunotherapeutic contexts that preserve the native tumor microenvironment.
Project description:Immune checkpoint blockade (ICB) has shown remarkable clinical efficacy across multiple cancer types. However, only a fraction of patients respond to ICB. Here, we performed pooled mutagenic screening with CRISPR-mediated genetically engineered mouse models (CRISPR-GEMMs) in ICB settings, and identified KMT2D as a major modulator of ICB response across multiple cancer types. Kmt2d encodes a histone H3K4 methyltransferase and is among the most frequently mutated genes in cancer patients. Kmt2d loss led to increased DNA damage and mutation burden, chromatin remodeling, intron retention, and activation of transposable elements. Additionally, Kmt2d-deficient cells exhibit increased protein turnover and IFN-γ-stimulated antigen presentation. In turn, Kmt2d-mutant tumors in both mouse and human are characterized by increased immune infiltration. These data demonstrate that KMT2D deficiency sensitizes tumors to ICB by augmenting tumor immunogenicity, highlighting the power of CRISPR-GEMMs for interrogating complex molecular landscapes in immunotherapeutic contexts that preserve the native tumor microenvironment.
Project description:Immune checkpoint blockade (ICB) has shown remarkable clinical efficacy in several cancer types. However, only a fraction of patients will respond to ICB. Here, we performed pooled mutagenic screening with CRISPR-mediated genetically engineered mouse models (CRISPR-GEMM) in ICB settings, and identified KMT2D as a major modulator of ICB response across multiple cancer types. KMT2D encodes a histone H3K4 methyltransferase and is among the most frequently mutated genes in patients with cancer. Kmt2d loss led to increased DNA damage and mutation burden, chromatin remodeling, intron retention, and activation of transposable elements. In addition, Kmt2d-mutant cells exhibited increased protein turnover and IFNγ-stimulated antigen presentation. In turn, Kmt2d-mutant tumors in both mouse and human were characterized by increased immune infiltration. These data demonstrate that Kmt2d deficiency sensitizes tumors to ICB by augmenting tumor immunogenicity, and also highlight the power of CRISPR-GEMMs for interrogating complex molecular landscapes in immunotherapeutic contexts that preserve the native tumor microenvironment. SIGNIFICANCE: ICB is ineffective in the majority of patients. Through direct in vivo CRISPR mutagenesis screening in GEMMs of cancer, we find Kmt2d deficiency sensitizes tumors to ICB. Considering the prevalence of KMT2D mutations, this finding potentially has broad implications for patient stratification and clinical decision-making.This article is highlighted in the In This Issue feature, p. 1775.
Project description:A collection of genetically engineered mouse models (GEMM) of colorectal cancer (CRC) were created, and primary tumors from these GEMMs were analyzed. Primary CRC tumors from these GEMMs were genotyped to confirm that they contain the core genetic lesions of interest, including APC, P53, KRAS, and BRAF. Primary tumors from GEMMs with combinations of lesions of interest were analyzed by whole genome expression, and their expression profiles were compared to determine how they segregate. Signatures were then generated from GEMM tumors of interest and compared to human clinical datasets with expression and outcome data. Primary tumors from CRC GEMMs with different combinations of mutant alleles of interested were generated and analyzed. Alleles include mutant forms of APC (A), P53 (P), KRAS (K) and BRAF (B).
Project description:A collection of genetically engineered mouse models (GEMM) of colorectal cancer (CRC) were created, and primary tumors from these GEMMs were analyzed. Primary CRC tumors from these GEMMs were genotyped to confirm that they contain the core genetic lesions of interest, including APC, P53, KRAS, and BRAF. Primary tumors from GEMMs with combinations of lesions of interest were analyzed by whole genome expression, and their expression profiles were compared to determine how they segregate. Signatures were then generated from GEMM tumors of interest and compared to human clinical datasets with expression and outcome data.
Project description:Genome-wide CRISPR screen in murine CH12F3-2 cell line to identify novel factors involved in antibody class switch recombination. FAM72A, a protein with no ascribed function, was identified in this screen as a major determinant during mutagenic uracil repair by antagonizing base excision repair protein UNG2.
Project description:Histone methyltransferase KMT2D is epigenetic modifier mediates histone H3 lysine 4 methylation (H3K4me) with distinct roles across different cancer types. We previous found that KMT2D promotes growth and metastasis in Androgen receptor (AR)-negative prostate cancer (PCa). However, the functions of KMT2D and the relationship with AR in AR-positive prostate cancer remain unclear. Here, we showed that inhibition of KMT2D reduced AR-positive PCa cell survival and the sensitivity to dihydrotestosterone, a ligand for AR. RNA-Seq analysis revealed that KMT2D suppression significantly attenuated AR signaling pathway. Through multiple-omics analysis, we revealed that KMT2D recruits pioneering transcription factor Forkhead box A1 (FOXA1) to AR-specific enhancer sites, induces open chromatin conformations, and facilitates AR binding at enhancers to activate downstream gene expression, ultimately leading to AR reactivation. KMT2D knockout by CRISPR/Cas9 reduced CRPC tumor growth and AR signaling pathway activation in vivo. KMT2D-FOXA1-AR axis also mediates ketone metabolic reprogramming by regulating the expression of the key enzyme HMGCS2 to promote PCa progression. Finally, targeting UTX, a member of complex of proteins associated with SET1 (COMPASS) in which KMT2D involved, suppressed PCa cell survival and tumor growth by impairing H3K4me1 modification via KMT2D. These findings demonstrate the oncogenic role of KMT2D in PCa, suggesting that blocking COMPASS to inhibition KMT2D’s function may be a promising strategy to treat PCa.
Project description:Histone methyltransferase KMT2D is epigenetic modifier mediates histone H3 lysine 4 methylation (H3K4me) with distinct roles across different cancer types. We previous found that KMT2D promotes growth and metastasis in Androgen receptor (AR)-negative prostate cancer (PCa). However, the functions of KMT2D and the relationship with AR in AR-positive prostate cancer remain unclear. Here, we showed that inhibition of KMT2D reduced AR-positive PCa cell survival and the sensitivity to dihydrotestosterone, a ligand for AR. RNA-Seq analysis revealed that KMT2D suppression significantly attenuated AR signaling pathway. Through multiple-omics analysis, we revealed that KMT2D recruits pioneering transcription factor Forkhead box A1 (FOXA1) to AR-specific enhancer sites, induces open chromatin conformations, and facilitates AR binding at enhancers to activate downstream gene expression, ultimately leading to AR reactivation. KMT2D knockout by CRISPR/Cas9 reduced CRPC tumor growth and AR signaling pathway activation in vivo. KMT2D-FOXA1-AR axis also mediates ketone metabolic reprogramming by regulating the expression of the key enzyme HMGCS2 to promote PCa progression. Finally, targeting UTX, a member of complex of proteins associated with SET1 (COMPASS) in which KMT2D involved, suppressed PCa cell survival and tumor growth by impairing H3K4me1 modification via KMT2D. These findings demonstrate the oncogenic role of KMT2D in PCa, suggesting that blocking COMPASS to inhibition KMT2D’s function may be a promising strategy to treat PCa.