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

描述（申请人提供）：肾细胞癌（RCC）是一种非常普遍的恶性肿瘤，死亡率很高。散发性和种系突变和/或von Hippel-Lindau （VHL）肿瘤抑制基因的缺失与不同程度的RCC风险有关。VHL患者有一个野生型VHL等位基因和一个灭活/突变的VHL等位基因。当VHL的正常拷贝丢失或失活时，肿瘤就会形成。鉴于VHL 2B错义突变会给RCC带来高风险，该项目旨在确定VHL失活后肾细胞中发生的关键分子变化，从而深入了解RCC肿瘤的形成。众所周知，在正常氧条件下，功能性pVHL蛋白靶向缺氧诱导因子（HIF）进行蛋白体降解，而在低氧条件下或VHL等位基因突变时，VHL无法调节HIF-1亚基。HIF-1亚基与HIF-2亚基二聚化，转移到细胞核并负责基因的转录激活。已经确定了一些HIF基因靶点；最明显的是那些对血管生成和葡萄糖代谢很重要的基因，它们在肾细胞癌和其他恶性肿瘤中通常是上调的。本项目的重点是利用转基因小鼠模型，通过比较HIF-11和/或HIF-21受VHL状态差异调控时的基因表达水平，确定HIF基因靶谱。为了更好地了解与RCC肿瘤形成相关的遗传变化，将使用新生条件Vhl null和Vhl 2B转基因小鼠系的原代上皮肾细胞，并在离体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天然环境，免疫功能受损小鼠的肾胶囊中，以研究它们的致瘤潜力。将鉴定生成的合并细胞系的细胞组成，以研究哪种细胞类型最易发生肿瘤。无论肾癌是由VHL疾病还是散发性突变引起的，这项研究对公众来说都具有重要意义，因为我们迫切需要了解肾细胞发生了什么变化才能成为致瘤性的。拟议的研究将确定最危险的细胞群，并分析这些危险细胞群中导致肿瘤生长的分子变化，以及确定这些变化的HIF基因靶谱，以便更深入地了解RCC的肿瘤发生。

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.