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 今年将有近12，000人死于肾癌。 发生von Hlippel about Lindau（VHL）基因突变和/或失活 作为早期的启动事件，促进大多数肾细胞的发育， 肾癌（RCC）。我们已经证明了延伸蛋白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 （细胞因子信号传导抑制因子）蛋白/延伸蛋白复合物。表达 肾癌细胞系（缺乏野生型）中的外源VHL基因产物 VHL）影响融合细胞的生长和分化特性 在细胞外基质（ECM）上生长。此外，VHL保护这些细胞免受 凋亡雅阁具有抑制细胞凋亡、抑制细胞凋亡的作用， 应激相关的信号传导途径（例如，缺氧），我们观察到VHL 利用内部翻译来合成功能性蛋白质， 确保VHL蛋白在以下条件下的足够水平的机制： 抑制帽依赖性翻译。综上所述，这些发现表明 VHL可能通过抑制肿瘤细胞增殖而发挥肿瘤抑制作用的假说， 应力信号（SOSS）通过修改（例如，泛素化） 参与细胞-细胞、细胞-ECM和应激相关通路的调节剂 发信号。本课题的主要目的是：（1）确定 VHL介导的细胞凋亡保护作用通过测定VHL的特异性调节因子 细胞凋亡常见于UV照射、血清饥饿和葡萄糖剥夺。 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细胞凋亡， 对能够逃脱凋亡的细胞施加压力;（2）研究 翻译和翻译后的机制和功能重要性 VHL的调节;（3）鉴定VHL活性的潜在靶点， VHL相关蛋白将在细胞应激、低表达和高表达条件下进行比较。 和高细胞密度以及塑料和ECM上。

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.