PDK1/Akt2/GSK-3信号传导通路在非小细胞肺癌中作用及调节机制的研究

As the intersection of several signaling pathways, Akt has become a focus in recent oncology researches. The results of our previous studies revealed the high expression of Akt2, PDK1 and GSK-3α/β in non-small cell lung cancer (NSCLC). Additionally, down-regulation of Akt2 by small interfering RNA (siRNA) in NSCLC cell line A549 increased the expression of GSK-3α significantly, while inhibited the growth, invasion in vitro and tumorigenicity in vivo of the target cells, indicating that the signaling pathway of PDK1/Akt2/GSK-3 with Akt2 at the core might be involved in the occurrence and development of NSCLC. However, the exact effects and mechanism was unclear. Consequently, the current study is designed to build up the stably single-transfected normal human bronchial epithelial cell lines and NSCLC cell lines by siRNA and/or over-expression vectors of PDK1, Akt2 and GSK-3α/β respectively. The function of the signaling pathway of PDK1/Akt2/GSK-3 will be studied with experiments in vitro and in vivo. Further more, molecular interactions in the dual-transfected NSCLC cell lines will be analyzed to elucidate the upstream and downstream regulatory mechanism of Akt2. We believe this study would provide more evidence of the effects of the PDK1/Akt2/GSK-3 signaling pathway in NSCLC and its regulatory mechanism, which might open a new window to the targeted therapies of NSCLC.

Akt因处于多条信号通路交点而成为肿瘤学研究热点。我们的前期研究结果显示：Akt2、PDK1及GSK-3α/β在NSCLC中均高表达；沉默NSCLC A549细胞株Akt2的表达，则GSK-3α表达显著增加，但细胞增殖、侵袭及裸鼠体内成瘤能力明显下降。据此推测：以Akt2为核心的PDK1/Akt2/GSK-3信号通路可能是影响NSCLC的重要因素，但机制尚不清楚。本研究拟构建PDK1、Akt2和GSK-3α/β siRNA和过表达载体，稳定转染人正常支气管上皮细胞株，体外观察该信号通路对正常支气管上皮细胞生物学行为的影响；同时构建 "单干预"的NSCLC细胞株，体外、体内研究该通路对NSCLC的作用；并通过"双干预"的方法分析分子间的相互影响，阐明Akt2的上、下游调节机制。本研究旨在系统探讨PDK1/Akt2/GSK-3信号通路在NSCLC中的作用和调节机制，为探寻治疗新靶点提供依据。

Akt因处于多条信号通路交点而成为肿瘤学研究的热点。我们的前期研究结果显示：PDK1、Akt2 及GSK-3α/β在非小细胞肺癌(non-small cell lung cancer,NSCLC)中高表达；沉默NSCLC A549细胞株中Akt2的表达，则GSK-3显著增加，且细胞增殖、侵袭及裸鼠体内成瘤能力明显下降。据此推测：以Akt2为核心的PDK1/Akt2/GSK-3信号通路可能是影响NSCLC的重要因素，但具体作用方式和调节机制尚不清楚。. 本研究作为小额探索项目，研究重点集中在Akt2和GSK-3β。我们首先以Akt2和GSK-3β在NSCLC中的临床意义为切入点，分析Akt2和GSK-3β表达与NSCLC患者临床病理特征的关系；再分别构建Akt2和GSK-3βsiRNA慢病毒载体，稳定感染NSCLC细胞株，观察抑制Akt2和GSK-3β表达对NSCLC细胞株体外、体内生物活性的影响；最后检测干预Akt2和GSK-3β表达后下游基因的表达水平，初步分析基因间的相互作用，明确Akt2和GSK-3β作用的信号通路机制。. 通过本研究的实施，阐明了Akt2和GSK-3β在NSCLC 中的作用及调节机制，揭示了PDK1/Akt2/GSK-3信号通路在NSCLC的意义，为后期探寻NSCLC治疗的新靶点提供了实验依据。同时公开发表论文3篇，其中SCI收录2篇；协助培养博士硕士研究生2名，博士后和青年科技骨干各1名。