Oct-4调控Survivin促进食管癌细胞增殖的分子机制及干预策略

Survivin (Sur) plays an important role in cancer cell proliferation and apoptosis. Survivin expression could promote cancer cells to escape apoptosis and aquire the abilit of infinite proliferation. Therefore, Survivin can be regarded as a important target in gene therapy. In previous research work, we found that P16 can decrease Survivin expression and induce apoptosis in cancer cells, but the nuclear transcription factor OCT-4 can increase Survivin expression and promote cancer cell proliferation. Further study demonstrated that P16 inhibits Survivin expression by suppressing AKT signaling, however, the mechanism of OCT-4 increasing Survivin expression is unknown. Because of no binding site for OCT-4 within Survivin promote,we conjecture that the effect of OCT-4 on Survivin is indirect. In this project, we will construct OCT and Survivin expressing vectors and shRNA vectors to investigate the regulatory mechanism of OCT-4 on Survivin. We also construct Survivin promoter-controlled fluorescent reporter gene vectors and their mutated vectors within CCND1, E2F, SP1 binding sites, and screen the mediator between OCT-4 and Survivin, for the purpose to clarify the molecular mechanism of Survivin expression regulation. On this basis, dual-targeted shRNA will be constructed to perform a series experiment in cancer cells and nude mouse model to improve esophageal gene therapy effect.

Survivin（Sur）在细胞增殖和凋亡平衡中起决定作用，食管癌细胞借助Sur表达而抵抗凋亡，达到无限增殖目的，成为肿瘤治疗重要靶标。在前期研究中我们发现P16下调Sur表达诱导癌细胞凋亡，而转录因子OCT-4能上调Sur表达促癌细胞增殖。深入研究发现P16通过抑制AKT信号通路下调Sur表达，但OCT-4上调Sur表达的机制不明。由于Sur启动子区无OCT-4结合位点，推测OCT-4调控Sur可能是间接的。本项目拟构建OCT-4和Sur表达载体及其特异性shRNA，研究OCT-4调控癌细胞Sur表达规律；构建Sur启动子控制的荧光报告基因载体，在启动子区CCND1、E2F、SP1等转录因子结合位点突变，筛选OCT-4调控Sur的中间调控因子，揭示食管癌细胞Sur表达的调节机制；在此基础上，设计针对OCT-4和Sur的双靶向shRNA，进行食管癌体内外增殖转移的干预性生物靶向治疗研究。

Survivin（Sur）在细胞增殖和凋亡平衡中起决定作用，食管癌细胞借助Sur表达而抵抗凋亡，达到无限增殖目的，成为肿瘤治疗重要靶标。在前期研究中我们发现P16下调Sur表达诱导癌细胞凋亡，而转录因子OCT-4能上调Sur表达促癌细胞增殖。深入研究发现P16通过抑制AKT信号通路下调Sur表达，但OCT-4上调Sur表达的机制不明。由于Sur启动子区无OCT-4结合位点，推测OCT-4调控Sur可能是间接的。本项目拟构建OCT-4和Sur表达载体及其特异性shRNA，研究OCT-4调控癌细胞Sur表达规律；构建Sur启动子控制的荧光报告基因载体，在启动子区CCND1、E2F、SP1等转录因子结合位点突变，筛选OCT-4调控Sur的中间调控因子，揭示食管癌细胞Sur表达的调节机制；在此基础上，设计针对OCT-4和Sur的双靶向shRNA，进行食管癌体内外增殖转移的干预性生物靶向治疗研究。.实验完成原定计划任务，包括：1）完成OCT-4上调Survivin表达与食管癌复发、转移、预后的关系的研究；2）完成对食管癌细胞系OCT-4和Survivin表达的增强和沉默、对Survivin基因野生型启动子和突变型启动子活性的鉴定，以及对癌细胞凋亡、细胞周期的观察，初步阐明OCT-4调控Survivin表达的分子机制，明确OCT-4和Survivin对癌细胞增殖、转移的促进作用；3）建立了针对OCT-4和Survivin双靶向shRNA腺病毒治疗方案，通过全面封闭癌细胞OCT-4和Survivin基因的表达，实现对食管癌增殖、迁移有效的干预；4）培养研究生3名，发表SCI论文3篇，影响因子均超过5分。