DLC-1过表达抑制结肠癌细胞生长及与Wnt/β-catenin信号通路的关系

Relationship between tumor suppressor gene DLC-1 and Wnt/ and β-catenin signal pathway

摘要:

目的：探讨在结肠癌细胞中抑癌基因DLC-1的作用及其与Wnt/β-catenin信号通路的关系。方法：以结肠癌SW480细胞系为实验对象，分为实验组（pcDNA3.1（+）-DLC-1组），阴性对照组[pcDNA3.1（+）组]及空白对照组（SW480组）。用携带抑癌基因DLC-1的重组慢病毒表达载体转染各组，用MTT法检测各组细胞增殖活性，用流式细胞仪检测各组凋亡率，用real-time PCR及Western blot分别检测各组Wnt/β-catenin信号通路相关基因β-catenin、GSK-3β和c-myc的表达水平。结果：慢病毒介导DLC-1过表达使结肠癌细胞SW480的增殖受到抑制，增殖率为0.546，凋亡率明显增加，为42.422+3.413。转染DLC-1基因的结肠癌SW480细胞中β-catenin和c-myc的mRNA及蛋白表达水平较空白对照组及阴性对照组均明显下降，而GSK-3β的mRNA及蛋白表达水平较空白对照组及阴性对照组则明显上升，差异具有统计学意义（P均=0.000）。结论：慢病毒介导DLC-1过表达在结肠癌中有明显的抑癌作用，这种作用与Wnt/β-catenin信号通路密切相关。DLC-1可能是Wnt/β-catenin信号通路的上游调节因子。

Abstract:

Objective：To investigate the effect of tumor suppressor gene DLC-1 on Wnt/β-catenin signaling pathway in colon cancer cell line SW480. Methods：Human colon cancer cell line SW480 was taken as research object and was divied into 3 groups：pcDNA3.1（+）-DLC-1 group，pcDNA3.1（+） group and SW480 group. Each group was transfected with recombinant lentiviral vector containing DLC-1 gene. MTT was applied to detect cell proliferation and flow cytometry was performed to detect cell apoptosis. Real-time PCR and Western blot were preformed to detect the mRNA and protein expressions of Wnt/β-catenint signaling pathway related genes（β-catenin，GSK-3β and c-my）. Results：The proliferation of SW480 cells was significantly inhibited（the proliferation rate was 0.546）and the apoptosis was increased（the apoptosis rate was 42.422+3.413） in pcDNA3.1（+）-DLC-1 group. Real-time PCR and Western blot determined that the mRNA and protein expressions of β-catenin and c-myc were down-regulated，and the mRNA and protein expressions of GSK-3β were up-regulated（P=0.000）. Conclusion：DLC-1 plays a suppression role in colon cancer cell，which asso－ciates with Wnt/β-catenint signaling pathway. DLC-1 may be the upstream adjustment factor of Wnt/β-catenint signal pathway.