Xp11.2易位性肾癌泛素化相关分子调控机制研究

Xp11.2易位性肾癌共同特征均涉及染色体易位及其所致转录因子TFE3过表达，患者通常预后较差。在前期工作中，通过基因芯片表达谱技术发现缺氧诱导因子HIF-1在此类肿瘤中上调，并提示可能受到泛素化机制的干预。但是TFE3与HIF-1这两个重要分子是如何通过泛素化途径发生作用以及此通路在Xp11.2易位性肾癌中的生物学功能目前尚不清楚。本项目利用多聚泛素亲和磁珠对泛素化蛋白进行亲和富集，然后采用SDS-PAGE分离、质谱鉴定等方法，比较泛素化差异性蛋白质谱。结合全基因组差异表达谱数据，观察泛素-蛋白酶体降解途径对肿瘤生物学行为的影响，逐步分析精细泛素化调控机制在TFE3和HIF1之间的作用地位，明确TFE3调控方式及HIF-1发生泛素化的精确位点，体内外模型中验证此调控机制与肿瘤生长和化疗药物敏感性之间的关系。有望为阐明Xp11.2易位性肾癌发病机制，特异性治疗靶点的鉴定提供有益启示。

Common features of Xp11.2 translocation renal cell carcinoma are involved in chromosomal translocations and induced transcription factor TFE 3 expression in patients with poor prognosis usually. In previous work, we found the upregulation of hypoxia inducible factor(HIF-1) in these tumors by gene chip expression analysis. And there is evidence that the intervention was involved by ubiquitination mechanism. However, how the two important molecules TFE3 and HIF-1 interact in this pathway in Xp11.2 translocation renal cell carcinoma biological function through the ubiquitin is still unclear. Polyubiquitin affinity beads of ubiquitinated protein affinity enrichment of the project, and the SDS-PAGE separation, mass spectrometry was used to compare ubiquitinated proteins difference. Combined with the expression data of whole genome differences, we will observe the effects of ubiquitin-proteasome degradation pathway in tumor's biological behavior, step by step analyse ubiquitin role of detailed regulatory mechanism between TFE3 and HIF1, assure the exact site in specific TFE3 regulating and HIF-1 ubiquitination, and verify the relationship among this signal pathway, tumor growth and chemosensitivity in vitro and in vivo model. In order to elucidate the pathogenesis of Xp11.2 translocation renal cell carcinoma, we hope this project can provide useful inspiration and identification of specific therapeutic targets.