Interrogation of MLL2 as a tumor suppressor gene in lung cancer

MLL2 作为肺癌抑癌基因的研究

基本信息

批准号：
8996556
负责人：
David MacPherson
金额：
$ 40.26万
依托单位：
FRED HUTCHINSON CANCER RESEARCH CENTER
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-03-01 至 2020-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8996556
关键词：
Acetylation Adenovirus Vector Applications Grants Binding Cancer cell line Cell Culture Techniques Cell Line Cells ChIP-seq Chromatin Cytomegalovirus Data Defect Development Enhancers Epigenetic Process Epithelial Cells Exhibits Fibroblasts Future Gene Expression Gene Targeting Genes Genome Genomic approach Histones Human Intervention Link Location Lung Lung Neoplasms MLL2 gene Malignant Epithelial Cell Malignant Neoplasms Malignant neoplasm of lung Mediating Methylation Methyltransferase Modeling Molecular Mus Mutate Mutation Neurosecretory Systems Pathway interactions Primary Neoplasm Publishing Role Series Signal Pathway Signaling Protein Squamous Cell Lung Carcinoma Survival Rate System TP53 gene Testing The Cancer Genome Atlas Therapeutic Intervention Transcript Transcriptional Regulation Tumor Suppressor Genes Tumor Suppressor Proteins base cancer type differential expression exome genome-wide histone methyltransferase in vivo knock-down lung Carcinoma lung small cell carcinoma methylation pattern mouse model mutant neoplastic cell novel therapeutics overexpression pre-clinical preclinical study public health relevance research study targeted treatment therapy development tool transcriptome tumor tumor heterogeneity tumorigenesis vector

项目摘要

DESCRIPTION (provided by applicant): Small cell lung carcinoma (SCLC) is the most aggressive form of lung cancer. With dismal survival rates and a lack of targeted therapies it is critical that we understand the major genes and pathways that drive SCLC. To identify new potential SCLC drivers, we have sequenced human SCLC exomes and transcriptomes and found frequent inactivating mutations in the histone methyltransferase MLL2. The Cancer Genome Atlas study of squamous lung carcinoma (SQCC) revealed that MLL2 is among the most frequently mutated genes in SQCC, suggesting that MLL2 may be a tumor suppressor across multiple lung cancer types. MLL2 is frequently mutated across many human cancers but there has been little study of the link between MLL2 and cancer. Our preliminary data provide functional evidence that MLL2 is a tumor suppressor. By conferring histone H3K4 monomethylation, MLL2 is newly emerging as a key regulator of transcriptional enhancer function but this role has not been explored in tumorigenesis. In this grant proposal, we interrogate MLL2 as a critical tumor suppressor in lung cancer. Specific Aim 1: To test the hypothesis that MLL2 is a tumor suppressor in lung cancer. We have previously used a sensitized autochthonous mouse model of SCLC to show that an SCLC-mutated gene is functionally important for SCLC. We propose to generate new models of MLL2-mutant SCLC and SQCC. The models will not only reveal mechanisms underlying MLL2 tumor suppressor activity but will be ideal preclinical tools for future testing of novel therapies directed towards vulnerabilities conferred by MLL2 inactivation. Specific Aim 2: To identify target genes and pathways regulated by MLL2 that promotes cancer. MLL2 is a methyltransferase that regulates histone H3K4 monomethylation, a mark of transcriptional enhancers. We hypothesize that MLL2 regulation of transcriptional enhancers controls the expression of tumor suppressive transcripts important for lung cancer suppression. We will use primary tumors and cell culture studies to identify transcriptional changes that depend on MLL2 status. Pathway analyses will determine whether known signaling pathways important for SCLC are altered upon MLL2 perturbation and will identify new pathways that may be important for SCLC. To identify direct MLL2-regulated enhancers in SCLC, ChIPseq analyses will determine which of the differentially expressed genes exhibit direct MLL2 binding and, upon MLL2 inactivation, decreased histone H3K4 monomethylation and other marks associated with active enhancers. A subset of direct MLL2 target genes may act themselves as SCLC tumor suppressors and will be examined for functional roles in SCLC. These studies will elucidate molecular underpinnings of MLL2-mutant lung cancer and will provide new mouse models for preclinical studies. As there are no targeted therapies for SCLC or SQCC, it is critical that we use rigorous mouse models to dissect the role of MLL2 in lung cancer.

描述（由申请人提供）：小细胞肺癌（SCLC）是肺癌最具侵略性的形式。由于生存率衰退和缺乏目标疗法，至关重要的是，我们了解驱动SCLC的主要基因和途径。为了鉴定新的潜在SCLC驱动因素，我们已经测序了人类SCLC外观和转录组，并发现在组蛋白甲基转移酶MLL2中频繁失活突变。鳞状肺癌（SQCC）的癌症基因组图集研究表明，MLL2是SQCC中最常见的突变基因之一，这表明MLL2可能是多种肺癌类型的肿瘤抑制剂。 MLL2经常在许多人类癌症中突变，但是几乎没有研究MLL2与癌症之间的联系。我们的初步数据提供了功能证据，表明MLL2是肿瘤抑制因子。通过赋予组蛋白H3K4单甲基化，MLL2是新兴的转录增强子功能的关键调节剂，但在肿瘤发生中尚未探索这种作用。在这项赠款建议中，我们将MLL2作为肺癌中的关键肿瘤抑制剂审问。具体目的1：测试MLL2是肺癌中肿瘤抑制因子的假设。我们以前已经使用了SCLC的敏化自动摄像小鼠模型，以表明SCLC突变的基因在SCLC上在功能上很重要。我们建议生成MLL2突变SCLC和SQCC的新模型。这些模型不仅会揭示MLL2肿瘤抑制剂活性的基础机制 MLL2失活赋予的漏洞。特定目的2：确定由促进癌症的MLL2调节的靶基因和途径。 MLL2是一种调节组蛋白H3K4单甲基化的甲基转移酶，这是转录增强剂的标志。我们假设转录增强剂的MLL2调节控制对抑制肺癌抑制至关重要的肿瘤抑制转录物的表达。我们将使用原发性肿瘤和细胞培养研究来确定取决于MLL2状态的转录变化。途径分析将确定在MLL2扰动时对SCLC重要的已知信号通路是否会改变，并确定可能对SCLC很重要的新途径。为了鉴定SCLC中的直接MLL2调节的增强子，ChiPSEQ分析将确定哪些差异表达的基因表现出直接的MLL2结合，并且在MLL2失活后，组蛋白H3K4单甲基化和其他与活性增强子相关的标记降低。直接MLL2靶基因的一部分可以充当SCLC肿瘤抑制子，并将检查在SCLC中的功能作用。这些研究将阐明MLL2突变肺癌的分子基础，并将为临床前研究提供新的小鼠模型。由于没有SCLC或SQCC的靶向疗法，因此我们必须使用严格的小鼠模型来剖析MLL2在肺癌中的作用。