ETK在肾细胞癌和肾细胞癌侧群细胞的作用及其机制研究

Renal cell carcinoma is resist to chemotherapy,radiotherapy and target therapy.Exploring the mechanisms in tumor initiation and progression and identifying effective theraputic target is very important in this field.Epithelial Tyrosine Kinase(ETK) is involved in many malignant tumors.Previous we demonstrated that ETK was overexpressed in renal cancer and negetive correlated with prognosis,knockdown ETK in 769P can inhibite proliferation and invasion,and ETK is actvated by VEGF.later we successfully isolate side population cell in 769P,and using protein chip we reveal that VEGFc is upregulation in SP cells,indicating that VEGFc is very important in SP cells.Previous studys show that ETK,VEGF act as a loop,and ETK can activate STAT3,while STAT3 transcripts VEGF.In this project we are planing to explore VEGFc-ETK-STAT3 loop in renal cancer, by in vitro expression correlation analyzing,co-immunoprecipitation,detecting phosphorylation of related protein and knockdown specific gene to validate the VEGFc-ETK-STAT3 loop in renal cancer and its mechanisms; by in vivo renal SP cells nude mouse model to explore the therapeutic value of VEGFc-ETK-STAT3 loop inhibitors,provide a theoretical basis for development of new drugs.

肾细胞癌对放化疗及靶向治疗效果有限，探索其分子机制、寻找更有效的治疗靶点是目前的研究热点。上皮性非受体酪氨酸激酶ETK广泛参与多种恶性肿瘤的发生发展。我们前期发现ETK在肾癌中高表达并与其预后负相关，沉默ETK可抑制肾癌细胞增殖、侵袭，且其功能可被VEGF激活。随后我们从肾癌细胞769P中首次分离出侧群细胞（SP）并证实其具有肿瘤干细胞特性，对SP细胞行蛋白芯片筛选发现VEGFc表达上调，提示VEGFc在SP细胞中有重要意义。研究表明ETK可通过STAT3调控VEGF转录。本研究我们以探索VEGFc-ETK-STAT3正反馈调控肾癌的作用机制为目标，体外通过表达相关性分析、免疫共沉淀、对肾癌SP细胞相关蛋白磷酸化水平检测、基因沉默技术等明确该正反馈调节对肾癌的作用机制；体内运用肾癌SP细胞建立裸鼠原位模型，探索抑制该通路对肾癌的治疗作用，为肾癌的新药开发提供理论依据。

肾细胞癌对放化疗及靶向治疗效果有限，探索其分子机制、寻找更有效的治疗靶点是目前的研究热点。上皮性非受体酪氨酸激酶ETK 广泛参与多种恶性肿瘤的发生发展，我们发现ETK 在肾癌中高表达并与其预后负相关，ETK 可通过STAT3调控肾癌细胞增殖、侵袭转移，且其功能可被VEGF 激活。随后我们从肾癌细胞769P 中分离出侧群细胞（SP）并证实其具有肿瘤干细胞特性，蛋白芯片发现VEGFc 表达上调，提示VEGFc 在SP 细胞中有重要意义，同时验证了ETK 可通过STAT3 调控VEGF 转录。我们从体外实验证实了ETK对肾癌肿瘤细胞增殖、凋亡、迁移和侵袭能力的重要作用，从肿瘤中分选出侧群细胞，证实了了VEGFc-ETK-STAT3 调控肾癌细胞及侧群细胞中的作用机制，探索抑制该通路对肾癌的治疗价值，为肾癌的新药开发提供理论依据。我们还研究了ETK对肾癌侧群细胞中的调节机制，发现下游蛋白激酶Cε（PKCε）可以抑制侧群细胞分选，调控侧群细胞生物学功能。