Using Synthetic Lethality to Select Cancer Drug Targets

描述（由申请人提供）：肿瘤抑制基因（TSG）突变功能丧失在癌症中很常见。如果两个基因中的任何一个单独失活与生存能力相容，但两个基因的失活都会导致死亡，那么这两个基因是“合成致死”的。从理论上讲，对突变的TSG具有合成致死性的基因产物将是一个有吸引力的药物靶标，因为它的抑制作用应该杀死TSG（-/-）癌细胞，而不是正常的[TSG（+/+）]细胞。我们选择了VHL肿瘤抑制基因，这是突变的大多数透明细胞肾癌，进一步探讨这一模式。重要的是，VHL基因产物pVHL的失活不会严重影响体外细胞生长，否则可能会混淆我们的研究。此外，我们有多个匹配的（同基因的）肾癌细胞（RCC）系，它们含有或不含有野生型pVHL以及VHL（+/+）和VHL（-/-）C。优雅缺乏pVHL的细胞过度产生一种称为HIF（缺氧诱导因子）的转录因子。因此，VHL（-/-）RCC的转录组类似于缺氧细胞的转录组，缺氧细胞在实体瘤中很常见，并且已知相对耐药。在具体目标1中，我们将使用化学生物学方法来寻找选择性杀死VHL（-/-）RCC的化合物。然后，这些化合物可以用作探针来识别它们的蛋白质靶点。在具体目标2中，我们将使用全基因组RNAi方法来鉴定选择性杀死VHL（-/-）C的基因。优雅然后将这些基因在人RCC中进行interrogated二次筛选将解决HIF的失调是否是VHL（-/-）和VHL（+/+）细胞在特定目标1和2中的差异敏感性的原因。这些实验可以确定新的药物靶点，特别是肾癌，和缺氧肿瘤细胞，一般。此外，他们可能会建立一个新的模式，选择抗癌药物的目标的基础上失活突变的TSG。

DESCRIPTION (provided by applicant): Loss of function tumor suppressor gene (TSG) mutations are common in cancer. Two genes are 'synthetically lethal' if inactivation of either gene alone is compatible with viability but inactivation of both genes leads to death. In theory, the product of a gene that was synthetically lethal to a mutated TSG would be an attractive drug target because its inhibition should kill TSG(-/-) cancer cells but not normal [TSG( +/+)] cells. We have chosen the VHL tumor suppressor gene, which is mutated in the majority of clear cell renal carcinomas, to explore this paradigm further. Importantly, inactivation of the VHL gene product, pVHL, does not grossly affect cell growth in vitro, which might otherwise confound our studies. Moreover, we have multiple matched (isogenic) renal carcinoma cell (RCC) lines that do or do not contain wild-type pVHL as well as VHL(+/+) and VHL (-/-) C. elegans. Cells lacking pVHL overproduce a transcription factor called HIF (hypoxia-inducible factor). Consequently, the transcriptomes of VHL (-/-) RCCs resemble that of hypoxic cells, which are common in solid tumors and known to be relatively chemoresistant. In specific aim 1 we will use chemical biological approaches to look for compounds that selectively kill VHL(-/-) RCCs. Such compounds might then be used as probes to identify their protein targets. In specific aim 2, we will use a genome-wide RNAi approach to identify genes that selectively kill VHL (-/-) C. elegans. These genes would then be interogated in human RCCs Secondary screens will address whether dysregulation of HIF is responsible for differential sensitivity of VHL (-/-) and VHL (+/+) cells in specific aims 1 and 2. These experiments may identify new drug targets for renal carcinoma, in particular, and hypoxia tumor cells, in general. Moreover, they may establish a new paradigm for the selection of anticancer drug targets based on inactivating mutations of TSG.