The Oncogenic and Tumor Suppressor Functions of the Kras isoform 4A in vivo

Kras 亚型 4A 体内的致癌和抑癌功能

基本信息

批准号：
9058497
负责人：
ALLAN BALMAIN
金额：
$ 47.06万
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：
2015
资助国家：
美国
起止时间：
2015-05-01 至 2017-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9058497
关键词：
Affect Alleles Alternative Splicing Apoptosis Biological Assay Biology Cancer cell line Carcinogens Cell Line Cell Proliferation Cells Cellular Assay Comparative Study Data Development Embryo Engineering Epithelial Cells Exons Frequencies Gene Chips Gene Expression Gene Expression Profiling Genotype Goals Growth Health Histologic Human In Vitro Individual KRAS2 gene Knock-in Lead Lung Lung Neoplasms Maintenance Malignant Neoplasms Malignant neoplasm of lung Mediating Minor Modeling Molecular Molecular Analysis Mus Mutation Oncogenes Oncogenic Pathway interactions Phase Phenotype Protein Isoforms Proteins Ras Signaling Pathway Reporting Resistance Role Signal Pathway Signal Transduction Skin Skin Neoplasms Structure of parenchyma of lung System Testing Therapeutic Time Tissues Tumor Burden Tumor Suppressor Proteins Urethane Wild Type Mouse Xenograft Model base cancer cell carcinogenesis design in vivo inhibitor/antagonist insight knockout gene lung carcinogenesis mouse model mutant novel success tumor tumor growth tumor initiation tumor progression

项目摘要

DESCRIPTION (provided by applicant): Activating mutations in KRAS occur frequently in some of the most common and deadliest of human cancers but efforts to target KRAS for therapeutic purposes have not been successful. KRAS generates two highly homologous isoforms (KRAS4A and KRAS4B) as a result of alternative splicing. While the complete Kras gene knockout in mice causes embryonic lethality, knock-in of either Kras4A (Kras4AKI) or Kras4B (Kras4BKI) at the expense of the alternate isoform results in viable mice. Kras4AKI mice express only Kras4A and Kras4BKI mice express only Kras4B, enabling for the first time a comparison of the individual roles of these Kras isoforms in transformation in vivo. We have found that Kras4BKI mice are highly resistant to the development Kras mutant lung and skin tumors, suggesting that Kras4A is essential for transformation in 2 independent tissues. Our studies further showed that Kras4A is also responsible for the previously reported tumor suppressor activity of wild type Kras. The overall goal of this proposal is to exploit these novel mouse models to study the functions of both Kras4A and Kras4B in lung cancer development, both as oncogenes (mutant form) and as tumor suppressors (wild type form). A major strength of this proposal is the availability of viable strains uniquely expressing each isoform, representing powerful and complementary in vivo systems for studies into the isoform specific functions of this major human oncogene. Aim 1 of this proposal will investigate the oncogenic function of individual Kras isoforms in vivo using models of carcinogen induced lung carcinogenesis. Aim 2 will investigate the tumor suppressor activity of wild type Kras4A and Kras4B in vivo in models of conditionally activatable mutant Kras (i.e. KrasLA2 and KrasLSL-G12D). Aim 3 will take advantage of lung epithelial cell lines derived from the various mouse models for detailed in vitro analyses of Kras4A and Kras4B signaling pathways in order to gain mechanistic insights into their oncogenic activities. Aim 4 will evaluate the roles of these individual KRAS isoforms in the growth/maintenance of human KRAS mutant lung cancer cells. Insights into the isoform specific functions of KRAS will not only be important to the understanding of cancer development but could potentially have major implications for therapeutic design.

描述（由申请人提供）：KRAS 的激活突变经常发生在一些最常见和最致命的人类癌症中，但针对 KRAS 进行治疗的努力尚未成功。由于选择性剪接，KRAS 产生两种高度同源的亚型（KRAS4A 和 KRAS4B）。虽然小鼠中 Kras 基因完全敲除会导致胚胎致死，但敲入 Kras4A (Kras4AKI) 或 Kras4B (Kras4BKI) 会导致小鼠存活。 Kras4AKI 小鼠仅表达 Kras4A，Kras4BKI 小鼠仅表达 Kras4B，首次能够比较这些 Kras 亚型在体内转化中的各自作用。我们发现 Kras4BKI 小鼠对 Kras 突变型肺肿瘤和皮肤肿瘤具有高度抵抗力，这表明 Kras4A 对于两种独立组织的转化至关重要。我们的研究进一步表明，Kras4A 也负责先前报道的野生型 Kras 的肿瘤抑制活性。该提案的总体目标是利用这些新型小鼠模型来研究 Kras4A 和 Kras4B 在肺癌发展中的功能，无论是作为癌基因（突变体形式）还是作为肿瘤抑制因子（野生型形式）。该提案的主要优点是可以获得独特表达每种亚型的可行菌株，代表强大且互补的体内系统，用于研究这种主要人类癌基因的亚型特定功能。该提案的目标 1 将利用致癌物诱导肺癌模型研究体内各个 Kras 亚型的致癌功能。目标 2 将在条件可激活突变体 Kras（即 KrasLA2 和 KrasLSL-G12D）模型中研究野生型 Kras4A 和 Kras4B 的体内肿瘤抑制活性。 Aim 3 将利用源自各种小鼠模型的肺上皮细胞系，对 Kras4A 和 Kras4B 信号通路进行详细的体外分析，以获得对其致癌活性的机制见解。目标 4 将评估这些单独的 KRAS 亚型在人类 KRAS 突变肺癌细胞的生长/维持中的作用。深入了解 KRAS 亚型特定功能不仅对于理解癌症发展很重要，而且可能对治疗设计产生重大影响。