ΔNp63上调EZH2表达促进食管鳞癌EMT及转移的作用机制研究

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. However, the role of ΔNp63 in the regulation of EMT in ESCC remains unknown..In a recent work we demonstrated that the expresssion of ΔNp63 in ESCC tissuses was significantly higher than that in matched normal tissues,and the the expresssion of ΔNp63 was correlated with metastasis in ESCC patients.In addition, we found that ΔNp63 significantly induced the expression of EZH2, which reportedly induces EMT in variety types of tumors.Moreover, over-expression of ΔNp63 (or EZH2) could induce EMT in ESCC cells.Therefore, we hypothesized that ΔNp63 might promote ESCC EMT and metastasis via ΔNp63 mediated up-regulation of EZH2 expression..In this project, we propose to evaluate the role of ΔNp63/EZH2 in the EMT of ESCC by multiple approaches including bioinformatic analysis, luciferase reporter assay, ChIP, adenovirus- (on 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 ΔNp63 will provide important clues for the development and evaluation of novel anticancer therapies.

上皮-间质转化（EMT）是上皮类肿瘤转移发生的早期事件。尽管研究发现ΔNp63表达与多种肿瘤的转移相关，但其作用及机制因瘤而异。我们在以往研究中首次证实，ΔNp63具有促进食管鳞癌EMT及侵袭转移作用。近来我们发现，ΔNp63可以上调食管鳞癌细胞中EZH2表达，且高表达EZH2同样具有促食管鳞癌细胞EMT发生的作用；此外，生物信息学分析显示EZH2启动子区域含有ΔNp63蛋白识别位点。据此我们假设：ΔNp63可通过上调EZH2表达进而促进食管鳞癌EMT及转移。本项目拟通过ChIP、荧光素酶报告基因及细胞学实验等对此加以证明。另外，我们还将通过动物模型及临床统计分析明确ΔNp63和EZH2对食管鳞癌转移的促进作用及其临床意义。鉴于目前尚无该途径调控肿瘤EMT的报道，因此本项目具有较强的创新性，如获成功，将对揭示ΔNp63调控食管鳞癌转移的机制以及今后开展相关的临床诊疗研究起到积极的推动作用。

上皮-间质转化（EMT）是上皮类肿瘤转移发生的早期事件。已有研究发现ΔNp63表达与多种肿瘤的转移相关，但其作用及机制因瘤而异。我们在以往研究中首次证实，ΔNp63具有促进食管鳞癌EMT及侵袭转移作用。近来我们发现，ΔNp63可以上调食管鳞癌细胞中EZH2表达，且高表达EZH2同样具有促食管鳞癌细胞EMT发生的作用；此外，生物信息学分析显示EZH2启动子区域含有ΔNp63蛋白识别位点。据此我们推测ΔNp63可通过上调EZH2表达进而促进食管鳞癌EMT及转移。本研究中我们通过染色质免疫共沉淀（chromatin immuneprecipitation，ChIP）、荧光素酶报告基因及相关细胞功能实验明确在食管鳞癌细胞中ΔNp63对EZH2的转录调控作用；通过构建表达ΔNp63及特异性针对EZH2的shRNA（或特异性针对ΔNp63的shRNA载体及表达EZH2）的腺病毒载体共转染非食管鳞癌细胞株，证实ΔNp63通过调控EZH2表达对细胞迁移、侵袭及EMT的促进作用。通过免疫缺陷小鼠转移成瘤实验对ΔNp63、EZH2及其靶基因的表达水平对肿瘤发生发展的影响。本研究结果有助于更好地阐释ΔNp63调控食管鳞癌EMT的作用机制，而且对今后开展临床食管鳞癌相关的诊疗新方法具有一定的理论指导作用。