下调P55PIK基因表达对乳腺癌MDA-MB-231细胞体外增殖和迁移能力的影响

Effect of siRNA-mediated P55PIK Downregulation on Proliferation and Migration of MDA-MB-231 Cells in vitro

目的通过RNA干扰(RNA interference,RNAi)抑制P55PIK基因表达,观察下调P55PIK对人乳腺癌细胞株MDA-MB-231体外增殖和迁移能力的影响。方法利用脂质体将特异性针对P55PIK的siRNA瞬时转染P55PIK高表达细胞株MDA-MB-231,以转染无关序列siRNA(siRNA-NC)和未转染细胞作为对照。通过Western blot检测其对P55PIK表达的下调效果,MTT法和Transwell实验分别检测MDA-MB-231细胞的增殖和迁移能力。结果 siRNA-P55PIK明显下调MDA-MB-231细胞中P55PIK蛋白的表达;MTT检测显示下调P55PIK后,MDA-MB-231生长明显受到抑制;Transwell实验显示siRNA-P55PIK组穿膜细胞数为(5.2±1.3),显著低于siRNA-NC组(18.6±3.8)和空白对照组(18.4±4.3)(P<0.05)。结论应用RNAi抑制P55PIK基因的表达可抑制MDA-MB-231细胞体外增殖和迁移能力,为乳腺癌的靶向治疗提供了新思路。

Objective To explore the effect of siRNA-mediated downregulation of P55PIK on proliferation and migration of breast cancer cells in vitro.Methods Western blot was used to detect the expression of P55PIK in 3 breast cancer cell lines（MDA-MB-231,MCF-7,and T47D）.P55PIK-targeted siRNA was transfected into MDA-MB-231 cells（high expression of P55PIK） through lipofectamine and downregulation of the targeted P55PIK was assessed by Western blot.MTT assay was used to estimate proliferation of cells.The ability of cell migration was assessed by using Transwell chamber migration models.Results P55PIK expression was obviously inhibited after siRNA-P55PIK transfection.After transfection,the proliferation of MDA-MB-231 cells was significantly inhibited compared to the blank and negative control groups（P0.05）.The number of migratory cells in siRNA-NC negative control group,blank group and siRNA-P55PIK transfection group was（18.6±3.8）,（18.4±4.3） and（5.2±1.3） respectively.Downregulation of P55PIK significantly reduced migration of MDA-MB-231 cells.Conclusion Downregulation of P55PIK expression could inhibit the in vitro proliferation and migration of human breast cancer cell line MDA-MB-231.This study provided preliminary results in the searching of targeted therapy for breast cancer.