Identifying a Hypoxia Inducible Factor target profile in Renal Cell Carcinoma tum

描述(申请人提供)：肾细胞癌(RCC)是一种高度常见的恶性肿瘤，死亡率很高。Von Hippel-Lindau(VHL)肿瘤抑制基因的零星和胚系突变和/或丢失与不同程度的肾癌风险有关。VHL病患者有一个野生型VHL等位基因和一个失活/突变的VHL等位基因。当VHL的正常拷贝丢失或失活时，就会发生肿瘤形成。鉴于VHL 2B错义突变给肾癌带来高风险，拟议的项目旨在确定VHL失活后肾细胞中发生的关键分子变化，从而为肾癌的形成提供洞察力。众所周知，在正常氧条件下，功能性pVHL蛋白以低氧诱导因子(HIF)为靶标进行蛋白酶体降解，而在低氧条件下或VHL等位基因突变时，VHL不能调节HIF-1亚单位。HIF-1亚基与HIF-2亚基二聚体，移位到细胞核，负责基因的转录激活。已经确定了一些HIF基因靶点；最值得注意的是那些对血管生成和葡萄糖代谢至关重要的基因，这些基因通常在肾癌和其他恶性肿瘤中上调。本项目的重点是通过使用转基因小鼠模型比较当HIF-11和/或HIF-21被VHL状态差异调控时的基因表达水平，以确定HIF基因的靶向。为了更好地了解与肾癌形成相关的遗传变化，将使用来自新生条件VHL缺失和VHL 2B转基因小鼠系的原代上皮肾细胞，并将在体外系统中进行最低限度的操作。之后，这些细胞将被重新引入它们的自然环境-免疫低下小鼠的肾胶囊，以研究它们的致瘤潜力。将确定产生的汇集细胞系的细胞组成，以调查哪种细胞类型最有可能发生肿瘤。无论肾癌是由VHL疾病还是零星突变引起的，这项研究对公众具有很大的重要性，因为我们必须了解肾细胞发生了什么变化才能成为肿瘤。这项拟议的研究将确定风险最高的细胞群体，分析导致肿瘤生长的风险细胞群体中的分子变化，并确定这些变化的HIF基因靶点，以更好地了解肾细胞癌的发生。

DESCRIPTION (provided by applicant): Renal cell carcinoma (RCC) is a highly prevalent malignancy with a high mortality rate. Sporadic and germline mutations and/or loss of the von Hippel-Lindau (VHL) tumor suppressor gene have been linked to varying levels of risk for RCC. VHL disease patients have one wild type VHL allele and one inactivated/mutated VHL allele. Tumor formation occurs when the normal copy of VHL is lost or inactivated. Given that VHL 2B missense mutation confers a high risk for RCC, the proposed project aims to identify key molecular changes that occur in renal cells following VHL inactivation that can provide insight into RCC tumor formation. It is well understood that functional pVHL protein under normal oxygen conditions targets hypoxia inducible factors (HIF) for proteosomal degradation, while under low oxygen conditions or mutated VHL allele, VHL fails to regulate HIF-1 subunits. HIF-1 subunits dimerize with HIF-2 subunits, translocate to the nucleus and are responsible for transcriptional activation of genes. Some HIF gene targets have been identified; most notably those important for angiogenesis and glucose metabolism, which are normally upregulated in RCC and other malignant tumors. The focus of this project is to identify a HIF gene target profile by comparing levels of gene expression when HIF-11 and/or HIF-21 are differentially regulated by VHL status using transgenic mouse models. To better understand the genetic changes associated with RCC tumor formation, primary epithelial kidney cells from newborn conditional Vhl null and Vhl 2B transgenic mouse lines will be used and will be harvested and minimally manipulated in an ex vivo system. After which, these cells will be reintroduced to their native environment, renal capsules of immunocompromised mice, to study their tumorigenic potential. The cellular composition of the generated pooled cell lines wilI be identified to investigate which cell type is most at risk for developing tumorigenesis. Whether renal carcinoma is due to VHL disease or sporadic mutations, this study bears great weight to the public, as it is imperative that we understand what changes occur in kidney cells to become tumorigenic. The proposed research will identify the most at-risk cell population and analyze the molecular changes in this at-risk cell population that result in tumor growth as well as identify a HIF gene target profile for these changes in order to have greater insight into RCC tumorigenesis.