Interaction of molecules with VHL-signaling pathway in renal cell carcinoma

本研究以参与上皮-间充质转化的TWIST为研究对象，研究其对VHL-HIF信号转导通路的影响。过度表达的Twist激活了HRE报告基因的活性。在低氧条件下用Twist激活血管内皮生长因子启动子的活性，用抗Twist抗体的染色质免疫沉淀(ChIP)法检测肿瘤细胞中Twist与血管内皮生长因子启动子的结合。芯片检测显示与血管内皮生长因子启动子有Twist结合。凝胶迁移率改变分析(EMSA)显示Twist与血管内皮生长因子启动子中的特定序列(转录起点上游约-1000bp)结合，提示Twist的表达参与了肾肿瘤的血管生成。

In this study, we focused on Twist, which is involved in EMT (epithelial-mesenchymal transition) and demonstrated its effect on VHL-HIF signaling pathway.Transcriptional activity of VEGF by Twist was measured by reporter assay using HIF responsive element (HRE) reporter plasmids co-transfected with Twist expression plasmid. Overexpressed Twist activated HRE reporter activity. VEGF promoter activity was activated by Twist in hypoxia.Binding of Twist to VEGF promoter in tumor cells were shown by chromatin immunoprecipitation (ChIP) assay using antibody against Twist. ChIP assay showed Twist binding to VEGF promoter. Electrophoresis Mobility Shift Assay (EMSA) were demonstrated to show binding of Twist for specific sequence (about -1000bp upstream from start point of transcription) in VEGF promoter.These data suggest that Twist expression involves in tumor vascularization in renal tumor.