REGULATORY PATHWAYS AND ROLE OF VPF/VEGF IN RENAL CANCER

VPF/VEGF 在肾癌中的调节途径和作用

• 批准号: 6376817
• 负责人: DEBABRATA MUKHOPADHYAY
• 金额: $ 14.49万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-08-11 至 2003-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6376817
• 关键词: Animalia; angiogenesis; biological signal transduction; carcinoma; cell line; gene expression; gene mutation; genetic regulation; genetic transcription; immunoprecipitation; kidney neoplasms; oncogenes; posttranscriptional RNA processing; protein kinase C; tissue /cell culture; transfection; tumor suppressor genes; vascular endothelial growth factors; western blottings

DESCRIPTION: (adapted from the investigator's abstract) In order to grow beyond minimal size, tumors must induce a new blood supply. Like many human carcinomas, renal cell carcinomas (RCC) are thought to induce angiogenesis by secreting an angiogenic cytokine, vascular permeability factor, also known as vascular endothelial growth factor (VPF/VEGF). Studies from several laboratories, including our own, have shown that a number suppressor gene, the von Hippel Lindau (VHL) gene, has an important role in regulating VPF/VEGF expression in RCC and that this regulation involves both transcriptional and post-transcriptional events. More recently, they have found that wild-type VHL (wt-VHL) selectively interactions with and thereby down-regulates the activities of two protein kinase C (PKC) isoforms, rho and sigma; when VHL is as functional, as in RCC, VPF/VEGF is overexpressed, suggesting that PKC rho and sigma are on the signaling pathway(s) by which VHL regulates VPF/VEGF expression. Other evidence suggests that oncogenes, notable Ras and Src, also regulate VPF/VEGF expression in several important tumors, likely also including RCC. The experiments proposed here are designed to investigate more carefully the signaling pathways by which a tumor suppressor gene (VHL) and oncogenes (Ras, Src) induce VPF/VEGF overexpression and thus angiogenesis in RCC. A first Aim will make use of dominant negative mutants of PKC rho and sigma in RCC cells to investigate the role of PKC rho and sigma in regulating VPF/VEGF expression at both transcriptional and post-transcriptional levels. The nature and consequences of physical interaction between PKC and wt-VHL will also be explored. For Aim 2, dominant negative mutants of Ras and Src will be utilized to investigate whether and by what pathways these signaling components regulate VPF/VEGF expression in RCC. Finally, a third Aim will determine whether RCC cells transfected with dominant negative mutants of PKC rho and sigma or of other protein kinases along the signaling pathways which regulate VPF/VEGF expression, down-regulate VPF/VEGF and inhibit tumor angiogenesis and growth in an animal model. These experiments will provide new and important information on the mechanisms of carcinogenesis and suggest new targets for intervention in RCC, a common, highly vascular, angiogenesis-dependent carcinoma that is resistant to currently available therapeis.

描述：（从研究者的摘要中改编）为了成长 除了最小的大小之外，肿瘤必须诱导新的血液供应。 像许多人一样 癌，肾细胞癌（RCC）被认为会诱导血管生成 通过分泌血管生成细胞因子，血管通透性因子，也 称为血管内皮生长因子（VPF/VEGF）。 研究 包括我们自己在内的几个实验室已经表明了一个抑制器 基因（Von Hippel Lindau（VHL）基因）在调节中具有重要作用 RCC中的VPF/VEGF表达，该法规涉及 转录和转录后事件。 最近，他们有 发现野生型VHL（WT-VHL）有选择地与此相互作用 下调两个蛋白激酶C（PKC）同工型的活性，Rho 和Sigma；当VHL与RCC一样，VPF/VEGF过表达时， 表明PKC Rho和Sigma在信号通路上 VHL调节VPF/VEGF表达。 其他证据表明癌基因， 著名的RAS和SRC，还调节了几种重要的VPF/VEGF表达 肿瘤，也可能包括RCC。 这里提出的实验是 旨在更仔细地研究信号通路 肿瘤抑制基因（VHL）和癌基因（RAS，SRC）诱导VPF/VEGF 过表达，因此在RCC中的血管生成。 第一个目标将利用 RCC细胞中PKC Rho和Sigma的主要阴性突变体研究 PKC Rho和Sigma在调节两者的VPF/VEGF表达中的作用 转录和转录后水平。 自然和 PKC和WT-VHL之间物理互动的后果也将是 探索。 对于AIM 2，RA和SRC的主要负突变体将是 用于研究这些信号是否以及是否途径 组件调节RCC中的VPF/VEGF表达。 最后，第三个目标 确定RCC细胞是否用主要的负阴性突变体转染 PKC Rho和Sigma或沿信号通路的其他蛋白激酶的 调节VPF/VEGF表达，下调VPF/VEGF并抑制肿瘤 动物模型中的血管生成和生长。 这些实验将提供 有关致癌机制和 提出了干预RCC的新目标，RCC是一种常见的高度血管， 血管生成依赖性癌对当前可用 治疗性。