PI3K/AKT 通路参与调控乳腺癌多药耐药和侵袭转移的研究

目的:探讨磷脂酰肌醇-3-激酶/丝苏氨酸蛋白激酶(phosphatidylinositol 3 kinase/serine-threonine kinase,PI3K/AKT)信号通路与乳腺癌多药耐药和侵袭转移的相关性。方法:以乳腺癌细胞系MCF-7为母本,持续低浓度加药诱导建立阿霉素(Adriamycin,ADR)耐药系MCF-7/ADR’。细胞免疫荧光检测两细胞系中磷酸化AKT(phosphorylated AKT,P-AKT)、P-糖蛋白(P-Glycoprotein,P-gp)、基质金属蛋白酶2(matrix metalloproteinase-2,MMP-2)的表达。PI3K抑制剂LY294002作用两系前后,Western Blot检测P-AKT、MMP-2、P-gp的表达改变及qRT-PCR检测MMP-2、MDR1的表达改变。结果:P-AKT、P-gp(MDR1)、MMP-2在MCF-7中为低表达或不表达,MCF-7/ADR’中为高表达。LY294002作用两系后,P-AKT、P-gp(MDR1)、MMP-2在MCF-7/ADR’中的表达明显减低(P<0.05),MCF-7无明显改变。结论:抑制PI3K/AKT信号通路可有效降低MCF-7/ADR’耐药和侵袭转移能力,PI3K/AKT通路是调控乳腺癌多药耐药和侵袭转移的重要信号通路之一。

PI3K/AKT Signalling Pathway Involves in the Modulation of Multidrug Resistance and Metastasis in Breast Cancer

Objective: To study the relationship between phosphatidylinositol 3 kinase/serine-threonine kinase(PI3K/AKT) signalling pathway and the resistance or invasive ability of breast cancer.Methods: MCF-7/ADR’ were established by culturing parental MCF-7 cells with increasing concentration of adriamycin.The expression of phosphorylated AKT(P-AKT),P-Glycoprotein(P-gp) and matrix metalloproteinase-2(MMP-2) was investigated by Immunofluorescence assay.The expression of P-AKT,P-gp and MMP-2 with or without treatment of the PI3K inhibitor LY294002 was investigated by Western blot assay.Real-time quantitative PCR assay was used to investigate the expression of MDR1 and MMP-2.Results: In MCF-7 cells,P-AKT,P-gp(MDR1) and MMP-2 were neither detected nor only weakly expressed.In MCF-7/ADR’ cells,the expression of P-AKT,P-gp(MDR1) and MMP-2 was increased.Treatment of MCF-7/ADR’ cells with LY294002 can seriously reduced the expression of P-AKT,P-gp(MDR1) and MMP-2.Significant differences were not observed in MCF-7 cells.Conclusion: The resistance and metastasis can be reduced significantly through suppression of the PI3K/AKT signalling pathway.PI3K/AKT kinase pathway may be important in the modulation of resistance and metastasis in breast cancer.