转录调控在肿瘤形成和演变过程中发挥着“枢纽”样作用，项目组前期实验发现Net基因能够抑制c-fos/AP-1的转录活性，进而抑制胰腺癌细胞的增殖和生长，但其上游调控机制尚不清楚。研究表明，Net基因表达及其抑癌功能的发挥受Ras-MAPKs信号磷酸化调节，而项目组近期研究发现miR-21能够激活胰腺癌细胞中Ras-MAPKs信号的磷酸化活性；qRT-PCR定量分析显示在同一胰腺癌组织或细胞中Net基因与miR-21表达呈反相关关系。由此推测，胰腺癌中可能存在着一条Ras-MAPKs信号介导miR-21负调控Net基因表达的调控途径。本课题将分别以miR-21和Net为调控靶点，通过基因敲除、基因转染等方法正负调控，在体内外验证miR-21通过Ras-MAPKs信号介导负调控Net基因表达在胰腺癌发生中的分子作用机制，这将为后续以miR-21和/或Net为靶点进行分子靶向干预提供新的治疗策略

Transcription regulation plays a pivotal role in tumorigenesis. Previous studies showed that ternary complex factor Net suppressed the transcriptional activation of c-fos/AP-1, and then can suppress proliferation and growth of pancreatic carcinoma cell, but the upstream regulatory mechanism is not clear. Studies showed that the expression and suppressor function of Net gene is regulated by Ras-MAPKs signaling phosphorylation. The recent studies of the project group showed that miR-21 can activate the phosphorylation activity of Ras-MAPKs signaling in pancreatic cancer cell lines; qRT-PCR quantitative analysis showed the expression of Net is conversely correlated with that of miR-21 in the same pancreatic carcinoma tissues or cell lines. Therefore, we hypothesis that there may exist a regulatory pathway which miR-21 regulates Net expression mediated by Ras-MAPKs signal pathway in pancreatic cancer. Hence, the project is about to validate the molecular mechanisms of miR-21 negatively regulating Net through Ras-MAPKs signaling by gene knockout and transfection method in vivo and in vitro. This might provide new therapeutic strategies for molecular targeted intervention of pancreatic carcinoma with miR-21 and/or Net as target point in the future.