靶向干预Dicer通过NOS2-NO信号通路轴抑制胰腺癌恶性生物学行为

Dicer is involved in carcinogenesis throught the micro RNA pathway since Dicer plays the vital roles in the regulation of the micro RNA pathway. Our preliminary data has shown that Dicer is upregulated in pancreatic cancer and targeting Dicer inhibits cell proliferation and induces cell apoptosis, while this role may be the micro RNA pathway independently. Based on the gene array data, using bioinformatic technology, we find that Dicer plays roles by the NOS2 signal pathway possibly. We speculate that in pancreatic cancer activated Dicer promotes cell proliferaion and anti-apoptosis through the NOS2-NO signal pathway axis. Here,using PCR, RNA array,co-IP and immuno-image in vivo et al, we try to investigate the effects of Dicer on bio-behavior in pancreatic cancer and address the interaction of Dicer and NOS2, and also to assess the synergistic role of target inhibiton Dice combining with Gemcitabine. Through this project, hopefully we would uncover the effects of Dicer and the molecular mechanisms in pancreatic cancer, and also get the supportive evidences for the clinical usage of small molecular Dicer inhibitor.

由于Dicer是调控微小RNA的关键分子，现有研究认为Dicer通过微小RNA信号通路参与恶性肿瘤发生及发展。我们在胰腺癌中却发现Dicer异常激活，靶向干预Dicer抑制癌细胞增殖、诱导凋亡，但其发挥作用为微小RNA通路非依耐途径。进一步应用生物信息学分析技术研究基因芯片结果，我们发现NOS2极有可能是Dicer调控的靶分子，据此推测胰腺癌中异常激活的Dicer分子，通过上调NOS2，提高组织细胞NO水平，诱导细胞增殖及抗凋亡，增强癌细胞恶性生物学表型。本项目拟从组织、细胞及整体三个水平，采用PCR、基因芯片、免疫共沉淀、活体荧光成像等方法，研究Dicer对胰腺癌生物学行为影响，确立Dicer对NOS2的调控作用，评价靶向干预Dicer联合吉西他滨的协同抗肿瘤效应。通过本项目研究，明确Dicer调控胰腺癌恶性生物学表型的分子机制，为靶向抑制Dicer的小分子药物临床应用奠定理论基础。

胰腺癌是一种异质性肿瘤，多种癌基因以及抑癌基因的突变参与其发生与发展。为深入探索胰腺癌发生发展的分子机制，首先我们发现GPR87在胰腺癌组织和细胞系中高表达，并与胰腺癌患者的不良预后相关。进一步研究发现GPR87促进胰腺癌增殖和转移，并参与激活NF-kB通路。第二，我们发现PES1在胰腺癌组织中高表达并参与促进胰腺癌增殖，深入研究发现胰腺癌细胞中存在CDK5/PES1/BRD4/c-Myc信号轴，并且PES1通过该信号轴调控BET抑制剂耐药，而使用CDK5抑制剂可阻断这一通路，从而改善BET抑制剂的抗胰腺癌效果。最后，我们分析数据库发现FASTKD2同样在胰腺癌中高表达并参与促进胰腺癌增殖和迁移，其具体机制可能是通过与BRD4结合上调c-Myc的表达来实现。综上所述，我们发现并鉴定出GPR87，PES1，FASTKD2三个癌基因，这三个基因可以作为胰腺癌潜在的治疗靶点，为后续胰腺癌的靶向治疗提供了理论支持。