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Role of KMT2D and aberrant enhancers in modulating tumor microenvironment in melanoma

KMT2D 和异常增强子在调节黑色素瘤肿瘤微环境中的作用

基本信息

批准号：
10219181
负责人：
Kunal Rai
金额：
$ 36.6万
依托单位：
UNIVERSITY OF TX MD ANDERSON CAN CTR
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2023-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10219181
关键词：
Behavior Biological Response Modifiers Biology CD8-Positive T-Lymphocytes CRISPR/Cas technology Cell Line Cells Chromatin Complex Data Disease Disease Progression EZH2 gene Enhancers Enzymes Epigenetic Process Event Evolution Gene Expression Genes Genetic Genetically Engineered Mouse Grant Hematologic Neoplasms Human IL11 gene Immune Immune Targeting Immunotherapy Individual Interferon Type II Interleukin-11 MLL2 gene Malignant Neoplasms Mediating Melanoma Cell Methyltransferase Modeling Molecular Mus Mutation PTEN gene Pattern Phenotype Play Property RNA interference screen Receptor Gene Regulation Role Shapes Solid Somatic Mutation System T-Lymphocyte Testing Therapeutic Tumor Suppressor Proteins Tumor-Derived Work base cancer cell conditional knockout differential expression epigenome experimental study fitness histone methyltransferase immune function immunoregulation in vivo insight interest knock-down melanocyte melanoma melanomagenesis mouse model mutant neoplastic cell novel therapeutic intervention receptor recruit response therapy resistant tumor tumor microenvironment tumor progression tumor-immune system interactions tumorigenesis tumorigenic

项目摘要

SUMMARY Cancer cells acquire genetic and epigenetic alterations that increase fitness and drive progression through multiple steps of tumor evolution. We have limited understanding of functional epigenetic events that are associated with melanoma progression. An in vivo RNAi screen focused on epigenetic regulators identified KMT2D, an H3K4 methyltransferase, as a tumor suppressor in melanoma. KMT2D harbors somatic mutations in various solid and hematological malignancies including in melanoma (~15%). Consistently, loss of KMT2D in a genetically engineered mouse model of melanoma bearing activated BRAFV600E and PTEN inactivation drastically accelerated melanomagenesis. Human mouse melanoma tumors with KMT2D loss displayed drastic alterations in enhancers (H3K4me1 and H3K27Ac) compared to wild type tumors and displayed poor survival. These enhancers targeted immune modulatory genes in the tumor cells and consistently KMT2D KO tumors showed altered tumor microenvironment. These data suggest that enhancer malfunction in melanomas due to mutations in KMT2D may promote highly tumorigenic behavior of melanoma cells. We hypothesize that KMT2D loss reprograms enhancers in melanoma and imparts aggressive properties to cancer cells by misregulation of immune microenvironment. Overall objectives of this grant to understand the define roles of KMT2D in modulating tumor microenvironment, test functionality of enhancer losses and determine molecular mechanism of preferential enhancer regulation by KMT2D in this system. Aim 1: To determine the mechanism of immune microenvironment alteration by KMT2D and its mutants in melanoma. In this aim, we will utilize iBIP;KMT2D mouse model and available human tumor data to determine alterations in immune microenvironment in KMT2D deficient conditions. Aim 2: To determine the functionality of immune enhancer losses in KMT2D deficient cells. In this aim, we will perform directed tests at functionality of enhancer loss on IFNg receptors and IL11 genes by CRISPR-Cas9 based enhancer deletion and epigenetic editing experiments. Aim 3: To determine the molecular mechanism of KMT2D mediated regulation of immune enhancers. Here we will perform mechanistic experiments to determine how KMT2D is recruited preferentially to immune enhancers. Together, our study will determine how enhancer reprogramming in tumors specifically those due to KMT2D loss reshape the tumor microenvironment which could provide insight into new therapeutic strategies in melanoma.

概括癌细胞获得遗传和表观遗传改变，通过以下方式增强健康并推动进展：肿瘤进化的多个步骤。我们对功能性表观遗传事件的了解有限与黑色素瘤的进展有关。体内 RNAi 筛选重点关注表观遗传调节因子 KMT2D 是一种 H3K4 甲基转移酶，作为黑色素瘤的肿瘤抑制因子。 KMT2D 存在体细胞突变各种实体和血液恶性肿瘤，包括黑色素瘤（约 15%）。一致地，KMT2D 的丢失具有 BRAFV600E 激活和 PTEN 失活的黑色素瘤基因工程小鼠模型显着加速黑色素瘤的生成。显示 KMT2D 缺失的人小鼠黑色素瘤与野生型肿瘤相比，增强子（H3K4me1 和 H3K27Ac）发生巨大变化，并且表现不佳生存。这些增强剂针对肿瘤细胞中的免疫调节基因并持续敲除 KMT2D 肿瘤表现出肿瘤微环境的改变。这些数据表明黑色素瘤中的增强子功能障碍由于 KMT2D 突变可能会促进黑色素瘤细胞的高度致瘤行为。我们假设 KMT2D 缺失会重新编程黑色素瘤中的增强子，并通过以下方式赋予癌细胞侵袭性：免疫微环境的失调。这笔赠款的总体目标是了解以下人员的定义角色： KMT2D 调节肿瘤微环境，测试增强子损失的功能并确定分子该系统中KMT2D优先调节增强子的机制。目的 1：确定 KMT2D 及其改变免疫微环境的机制黑色素瘤中的突变体。为此，我们将利用 iBIP;KMT2D 小鼠模型和可用的人类肿瘤数据来确定改变在 KMT2D 缺陷条件下的免疫微环境中。目标 2：确定 KMT2D 缺陷细胞中免疫增强剂损失的功能。为此，我们将通过以下方法对 IFNg 受体和 IL11 基因的增强子丢失功能进行定向测试：基于 CRISPR-Cas9 的增强子删除和表观遗传编辑实验。目标 3：确定 KMT2D 介导的免疫增强剂调节的分子机制。在这里，我们将进行机制实验来确定 KMT2D 如何优先招募到免疫增强剂。我们的研究将共同确定肿瘤中的增强子重编程，特别是 KMT2D 引起的肿瘤中的增强子重编程损失重塑肿瘤微环境，这可以为新的治疗策略提供见解黑色素瘤。