AQP-5对结直肠癌细胞生长的影响及机制

目的 探讨水通道蛋白-5(AQP-5)对细胞增殖及凋亡影响及可能的机制.方法 体外常规培养人结直肠癌COLO 205和SW480细胞,取对数生长期的细胞用于实验.通过siRNA技术抑制内源性AQP-5的表达,并经免疫荧光、PCR检测AQP-5-siRNA转染效率,利用MTT法检测细胞增殖能力,Annexin V-FITC/PI和TUNEL检测细胞凋亡情况,RT-PCR和Western blot检测Bax、Bcl-2表达变化.结果 在COLO 205和SW480细胞株中,转染AQP-5-siRNA后AQP-5表达下调达90%.MTT分析结果显示,与转染NS-siRNA组相比,转染AQP-5-siRNA组的细胞增殖抑制率显著增加(P<0.05);流式细胞分析结果发现,与NS-siRNA组细胞相比,转染AQP-5-siRNA后细胞凋亡率显著增加(P<0.05);荧光实时定量RT-PCR和蛋白质印迹法检测结果显示:与转染NS-siRNA组相比,转染AQP-5-siRNA明显提升Bax/Bcl-2 mRNA和蛋白的表达.结论 AQP-5-siRNA可体外促进结直肠癌细胞凋亡,其机制可能与Bax/Bcl表达有关.

Role of aquaporin-5 in regulating colorectal cancer cell growth in vitro

Objective Tostudy the role of aquaporin-5(AQP-5) in regulating the cell proliferation and apoptosis of human colorectal cancer cells and explore the possible mechanism.Methods A small interfering RNA(siRNA)targeting AQP-5 was used to suppress endogenous AQP-5 expression in the human colorectal cancer cell lines COLO 205 and SW480, and the transfection efficiency of AQP-5-siRNA was determined using immunofluorescence assay and PCR. The changes in the proliferation of the transfected cells was evaluated with MTT assay,and the cell apoptosis was analyzed using Annexin V-FITC/PI and TUNEL assays; the changes of Bax and Bcl-2 expressions in the cells were determined using RT-PCR and Western blotting.Results Transfection with AQP-5-siRNA resulted in a significant reduction(up to 90%)of AQP-5 expression in COLO 205 and SW480 cells.MTT assay showed that AQP-5-siRNA transfection significantly inhibited the cell proliferation compared NS-siRNA transfection (P<0.05). Flow cytometric analysis revealed significantly increased apoptotic rate of cells following AQP-5-siRNA transfection compared with NS-siRNA transfection(P<0.05). Real-time quantitative RT-PCR and Western blotting demonstrated that AQP-5-siRNA transfection significantly increased Bax and Bcl-2 expressions at both mRNA and protein levels in the cells.Conclusion AQP5-siRNA can promote apoptosis of colorectal cancer cells in vitro possibly in relation to its effects on Bax and Bcl expressions.