Functional Analysis of the VHL Tumor Suppressor Gene

描述：(由申请人提供)大约30,000名美国人将 今年患上肾癌，将有近12,000人死于这种疾病。 Lindau(VHL)基因的von Hlippel发生突变和/或失活 作为一个早期的启动事件，促进了大多数肾细胞的发育 肿瘤(RCC)。我们已经证明了Elongins B&C的结合 以类似于SOCS的方式保护VHL蛋白免受蛋白酶体降解 (细胞因子信号转导抑制因子)蛋白质/细长蛋白复合体。的表达 外源性VHL基因产物(S)在肾癌细胞系(缺失野生型)中的表达 VHL)影响融合细胞的生长和分化特性 生长在细胞外基质(ECM)上。此外，VHL保护这些细胞免受 细胞凋亡。与VHL抑制细胞凋亡和抑制细胞凋亡的功能相一致 应激相关信号通路(如缺氧)，我们观察到VHL 利用内部翻译来合成一种功能蛋白质 在以下条件下确保VHL蛋白水平的机制 禁止大写字母相关的转换。综上所述，这些发现表明 VHL可能通过抑制VHL而发挥肿瘤抑制作用的假说 通过键的修饰(例如，泛素化)产生的应力信号(SoS) 细胞-细胞、细胞外基质和应激相关信号通路的调节 发信号。本项目的目标是：(1)确定 VHL介导的细胞凋亡保护作用 细胞凋亡是紫外线照射、血清饥饿和葡萄糖缺乏所常见的。 我们还将评估VHL中特定突变的促凋亡潜力。 并研究这些突变是否驱动了细胞凋亡并提供了选择性 对能够逃脱凋亡的细胞的压力；(2)研究 翻译与后翻译的机制及功能重要性 VHL的调控；(3)确定VHL活动的潜在靶点， VHL相关蛋白将在细胞应激、低浓度 和高细胞密度以及对塑料和ECM的影响。

DESCRIPTION: (provided by applicant) Approximately 30,000 Americans will develop renal cancer this year and nearly 12,000 will die from the disease. Mutation and/or inactivation of the von Hlippel about Lindau (VHL) gene occurs as an early, initiating event, promoting the development of most renal cell carcinoma (RCC). We have demonstrated that the binding of Elongins B & C protects VHL proteins from proteasomal degradation, in a manner similar to SOCS (suppressor of cytokine signaling) protein/elongin complexes. Expression of exogenous VHL gene product(s) in a renal cancer cell line (lacking wild type VHL) influences the growth and differentiation properties of confluent cells grown on extracellular matrix (ECM). In addition, VHL protects these cells from apoptosis. In accord with the function of VHL to inhibit apoptosis and suppress stress-related signaling pathways (e.g., hypoxia), our observation that VHL utilizes internal translation to synthesize a functional protein suggests a mechanism to assure adequate levels of VHL protein under conditions of suppressed cap-dependent translation. Taken together, these findings suggest the hypothesis that VHL may function as a tumor suppressor by suppression of stress signals (SOSS) through modification (e.g., ubiquitination) of key regulators of pathways involved in cell-cell, cell-ECM and stress-related signaling. The aims of this project are: (1) To determine the mechanism of VHL-mediated protection from apoptosis by assaying specific regulators of apoptosis common to UV irradiation, serum starvation, and glucose deprivation. We will also evaluate the pro-apoptotic potential of specific mutations in VHL and investigate whether these mutations drive apoptosis and provide selective pressure toward cells that are able to escape apoptosis; (2) To investigate the mechanism and functional imnportance of translational and post-translational regulation of VHL; (3) To identify potential targets of VHL activity, VHL-associating proteins will be compared under conditions of cell stress, low and high cell density and on plastic and ECM.