OVEREXPRESSION OF MDM2 IN THE ETIOLOGY OF BREAST CANCER

乳腺癌病因中 MDM2 的过度表达

• 批准号: 6376402
• 负责人: Swati P. Deb
• 金额: $ 22.91万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-20 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6376402
• 关键词: 3T3 cells; MCF7 cell; RNA splicing; athymic mouse; breast neoplasms; carcinogenesis; carcinogenesis inhibitor; cell growth regulation; cellular oncology; complementary DNA; cyclin dependent kinase; cyclins; disease /disorder etiology; enzyme activity; flow cytometry; gene expression; neoplasm /cancer genetics; oncoproteins; protein binding; transfection

The long-term goal of this proposal is to understand the normal biological function of the hMDM2 oncoprotein and how its overexpression can induce tumorigenesis. The short-term objective is to test the hypothesis that hMDM2 induces cell cycle arrest, possibly by interacting with the cell cycle regulatory proteins. Inactivation of this function is one of the causes of tumorigenesis. The working hypotheses are based on the exciting observations that mMDM2 induces GO/G1 arrest in normal human diploid cells. Elimination of the growth arrest function enhances the tumorigenic potential of NIH3T3 cells. Furthermore, hMDM2 associates with two cell cycle regulatory proteins, cyclin E and p34 (cdc2). This proposal has four specific aims. 1) Consequence of hMDM2 overexpression in normal breast epithelial cells and breast tumor- derived cells will be analyzed. The domain(s) of hMDM2 needed to confer these growth alterations will be determined using deletion mutants of the oncoprotein. Identification of these domains will enable us to detect interactions of hMDM2 with other proteins (such as cyclin E) important for cellular growth regulator functions. 2) Different splice variants of mdm2 mRNA will be isolated from an hMDM2 overexpressing breast cancer cell line MCF-7 and a murine tumorigenic cell line 3T3DM (harbors amplified mdm2 gene). The growth regulatory properties of the proteins encoded by the different splice variants will be analyzed. 3) The consequence of hMDM2-cyclin E interaction on the cyclin E-associated kinase -activity and on cell growth will be determined. 4) Since hMDM2 associates with P34 (cdc2), how hMDM2 modulates the activation of p34 (cdc2) kinase activity and how this interaction modulates cell growth will be determined. Completion of these specific aims will elucidate a novel growth regulatory function of hMDM2 and how perturbation of that function leads to tumorigenesis.

这项提议的长期目标是理解正常的 HMDM2癌蛋白的生物学功能及其过度表达 会导致肿瘤的发生。短期目标是测试 HMDM2可能通过相互作用诱导细胞周期停滞的假说 与细胞周期调节蛋白有关。停用此功能 是肿瘤发生的原因之一。工作假说是基于 关于mMDM2诱导正常人GO/G1期停滞的令人兴奋的观察 人类二倍体细胞。消除增长停滞功能增强 NIH3T3细胞的致瘤潜能。此外，hMDM2 与两种细胞周期调节蛋白Cyclin E和p34有关 (Cdc2)。这项提议有四个具体目标。1)hMDM2的后果 正常乳腺上皮细胞和乳腺肿瘤中的过度表达- 将对衍生细胞进行分析。需要授予的hMDM2的域名(S) 这些生长变化将使用缺失突变体来确定 癌蛋白。识别这些领域将使我们能够 检测hMDM2与其他蛋白质(如细胞周期蛋白E)的相互作用 对细胞生长调节功能很重要。2)不同的拼接 将从hMDM2过度表达的hMDM2中分离出MDM2 mRNA的变体 乳腺癌细胞系MCF-7和小鼠成瘤细胞系3T3 DM (携带扩增的MDM2基因)。的生长调节特性 不同剪接变体编码的蛋白质将被分析。3) HMDM2与细胞周期蛋白E相互作用对细胞周期蛋白E相关蛋白的影响 将确定激酶活性和对细胞生长的影响。4)从hMDM2开始 与p34(Cdc2)相关，hMDM2如何调节p34的激活 (Cdc2)激酶活性及其相互作用如何调节细胞生长 将会被确定。完成这些具体目标将阐明 HMDM2新的生长调控功能及其扰动 功能导致肿瘤的发生。