MiR-214下调CrkL抑制食管鳞癌上皮-间质转化及转移的机制研究

上皮-间质转化（EMT）与上皮类肿瘤的转移发生密切相关。近年来有关miRNA调控肿瘤EMT的机制研究取得了一定进展，但目前关于miRNA对食管鳞癌EMT的调控作用及其机制尚不明确。前期我们发现，食管鳞癌中miR-214的表达水平与EMT及侵袭转移呈显著负相关，细胞学实验提示miR-214可能通过下调Crk样蛋白（CrkL）表达抑制食管鳞癌EMT，但其具体的机制仍有待于进一步明确。本项目拟通过荧光素酶报告基因实验明确miR-214抑制CrkL的作用，采用酵母双杂交、生物信息学分析、免疫共沉淀、荧光共振能量转移及细胞功能实验明确CrkL调控EMT的途径，籍此建立miR-214下调CrkL表达抑制食管鳞癌EMT的信号通路；此外，通过动物转移成瘤模型及临床统计分析评价miR-214、CrkL及CrkL靶基因在食管鳞癌转移诊疗中的潜在应用价值，为今后临床开展食管鳞癌转移相关的诊疗新方法提供理论依据。

Increasing evidence supports a role for epithelial-mesenchymal transitions (EMT) in the acquisition of migratory and invasive properties that promote the dissemination of tumor cells and metastasis. Recent reports further demonstrated that microRNA-214 (miR-214) regulate EMT in several cancers. However, the role of miR-214 in the regulation of EMT in esophageal squamous cell carcinoma (ESCC) remains unknown. In a recent work we demonstrated that the expresssion of miR-214 in ESCC tissuses was significantly lower than that in matched normal tissues,and the the expresssion of miR-214 was negatively correlated with metastasis in ESCC patients.In addition, we found that miR-214 significantly repressed the expression of CT10 regulator of kinase like protein (CrkL), which reportedly induces EMT in variety types of tumors.Moreover, over-expression of miR-214 could repress EMT in ESCC cells. We, therefore, hypothesized that miR-214 might inhibit ESCC EMT and metastasis via miR-214 mediated down-regulation of CrkL expression. In this project, we plan to evaluate the role of miR-214/CrkL in the EMT of ESCC by multiple approaches including bioinformatic analysis, luciferase reporter assay,yeast two-hybrid, ChIP, fluorescence resonance energy transfer, adenovirus- (or lentivirus-) mediated gene delivery, metastasis assay in NOD/SCID mice and clinical investigation. Conceivably, elucidation of the molecular pathways involved in the EMT of ESCC by miR-214 will provide important clues for the development and evaluation of novel anticancer therapies.