Investigating the not so minor role of the minor isoform Kras4A in cancer

研究次要亚型 Kras4A 在癌症中的重要作用

基本信息

批准号：
8716523
负责人：
Peter Maxwell Kienitz Westcott
金额：
$ 3.61万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-01 至 2015-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8716523
关键词：
Ablation Address Adult Affect Alleles Alternative Splicing Animals Backcrossings Biochemical Biology Carcinogens Cell physiology Cells Chromosome Mapping Clara cell Clinical Management Collaborations Coupling Data Data Collection Development Dimerization Epithelial Cells Event Future Genes Genetic Genome Harvest Health Sciences Human Image In Vitro KRAS2 gene Knowledge Label Link Lung Lung Neoplasms Malignant Neoplasms Maps Microarray Analysis Microscopy Minor Mouse Cell Line Mus Mutation Natural regeneration Oncogene Proteins Oregon Pathway interactions Patients Pattern Play Population Predisposition Protein Isoforms Proteins Proto-Oncogenes RNA Splicing Regulation Resistance Role SNP genotyping Signal Pathway Signal Transduction Solid Neoplasm Specificity Stem cells Surface Technology Testing Tissues Tumor Stem Cells Tumor Suppression Tumor Suppressor Proteins Universities Urethane Western Blotting airway epithelium cancer stem cell carcinogenesis cell transformation genetic linkage analysis genome-wide in vivo in vivo Model lung carcinogenesis lung regeneration lung tumorigenesis mouse model mutant neoplastic cell novel outcome forecast public health relevance recombinase repaired research study therapeutic target therapy design tumor tumor initiation tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): We are only beginning to scratch the surface of the complexity underlying the role of KRAS in cancer, and there is a pressing need for a deeper understanding of KRAS biology in order to develop effective targeted therapeutics. Intriguingly, the KRAS gene encodes two proteins, KRAS4A and KRAS4B, and there is profound evidence from in vivo mouse models that suggests that the often ignored and poorly understood Kras4A protein is the main player in the development of mutant Kras tumors. Specifically, mice with Kras4B but not Kras4A are highly resistant to carcinogen-induced lung tumors, and there is evidence that Kras4A may play a role in lung stem cells and tumor initiating cells. Furthermore, we have compelling preliminary evidence showing that the Kras4A proto-oncogene (WT Kras4A) interacts with mutant Kras, and that this interaction depends on the type of activating mutation in Kras and influences the selection of tumor initiating cells. Objectives: This study wil (1) define the role of Kras4A expressing cells in vivo in the normal lung and in cancer development; (2) define the signaling features unique to Kras4A and the biochemical interactions underlying the role of Kras4A in tumor cell selection; and (3) identify novel genetic loci which modulate these features of Kras4A in tumorigenesis, which will broaden our understanding of the genetic context in which Kras functions, and may reveal new pathways and genes that converge with KRAS function that can be pharmacologically targeted to treat cancer. Three specific aims are proposed to address these objectives: Aim 1: Determine the role of Kras4A in lung regeneration and tumorigenesis using in vivo models A novel mouse model coupling Cre-recombinase and Kras4A expression (Kras4ACreERT2) will be used to label Kras4A expressing cells in the lung, and to interrogate the role of these cells in lung regeneration and tumor initiation. Kras4A expressing cells will be traced after airway damage, and after tumor induction. Aim 2: Functionally analyze Kras4A signaling in vitro Kras4A signaling pathways will be determined by biochemical analyses of canonical Ras effector pathways and genome-wide expression array experiments in MEFs and epithelial cells with and without Kras4A. The biochemical interaction of WT Kras4A with different mutant oncoproteins of Kras will be explored by analysis of signaling and Kras dimerization, in collaboration with the lab of Dr. Xiaolin Nan. Aim 3: Identify genetic factors in mice that interact with Kras in modulating lung tumor initiation. Tissue already collected from 3 populations of backcrossed mice totaling nearly 400 animals will be used to map genetic factors that are involved in the selection of tumor cells harboring specific mutations at Kras, as well as genetic factors involved in the regulation o Kras splicing and Kras4A expression.

描述（由申请人提供）：我们才刚刚开始触及 KRAS 在癌症中作用的复杂性的表面，迫切需要更深入地了解 KRAS 生物学，以便开发有效的靶向治疗。有趣的是，KRAS 基因编码两种蛋白，KRAS4A 和 KRAS4B，来自体内小鼠模型的深刻证据表明，经常被忽视和知之甚少的 Kras4A 蛋白是突变 Kras 肿瘤发展的主要参与者。具体来说，携带Kras4B但不携带Kras4A的小鼠对致癌物诱发的肺肿瘤具有高度抵抗力，并且有证据表明Kras4A可能在肺干细胞和肿瘤起始细胞中发挥作用。此外，我们有令人信服的初步证据表明Kras4A原癌基因（WT Kras4A）与突变的Kras相互作用，并且这种相互作用取决于Kras激活突变的类型并影响肿瘤起始细胞的选择。目的：本研究将 (1) 明确 Kras4A 表达细胞在体内正常肺和癌症发展中的作用； (2) 定义Kras4A独特的信号传导特征以及Kras4A在肿瘤细胞选择中作用的生化相互作用； (3) 鉴定在肿瘤发生中调节 Kras4A 这些特征的新基因位点，这将拓宽我们对 Kras 功能的遗传背景的理解，并可能揭示与 KRAS 功能融合的新途径和基因，可以通过药理学靶向治疗癌症。提出了三个具体目标来实现这些目标：目标 1：使用体内模型确定 Kras4A 在肺再生和肿瘤发生中的作用耦合 Cre 重组酶和 Kras4A 表达 (Kras4ACreERT2) 的新型小鼠模型将用于标记 Kras4A 表达细胞肺，并研究这些细胞在肺再生和肿瘤发生中的作用。 Kras4A 表达细胞将在气道损伤后和肿瘤诱导后被追踪。目标 2：体外对 Kras4A 信号传导进行功能分析 Kras4A 信号传导途径将通过对典型 Ras 效应途径的生化分析以及在含有和不含有 Kras4A 的 MEF 和上皮细胞中进行全基因组表达阵列实验来确定。将与实验室合作，通过信号传导和 Kras 二聚化分析，探索 WT Kras4A 与 Kras 不同突变癌蛋白的生化相互作用南晓林博士。目标 3：鉴定小鼠中与 Kras 相互作用调节肺肿瘤发生的遗传因素。已从 3 个回交小鼠群体（总计近 400 只动物）中收集的组织将用于绘制参与选择具有 Kras 特定突变的肿瘤细胞的遗传因子，以及参与调节 Kras 剪接和 Kras4A 表达的遗传因子。