目的:研究磷脂酰肌醇3-激酶/蛋白激酶B(PI3K-Akt)信号通路对人大肠癌hct-8/FU耐药细胞P-糖蛋白(P-GP)表达和耐药性的影响,探讨其逆转hct-8/FU多药耐药性的作用。方法:MTT法检测人大肠癌hct-8细胞、hct-8/FU耐药细胞、PI3K-Akt通路抑制剂LY294002处理的hct-8/FU耐药细胞对5-FU的半数生长抑制率和耐药指数;蛋白质印迹法检测hct-8、hct-8/FU细胞、LY294002处理的hct-8/FU耐药细胞PI3K、Akt、P-Akt、P-GP的表达变化。结果:大肠癌hct-8细胞对5-FU的半数生长抑制率为(43.2±1.4)mg·L-1,hct-8/FU耐药细胞为(516.00±20.03)mg·L-1,耐药指数为11.9;LY294002处理hct-8/FU耐药细胞后半数生长抑制率为(58.2±4.3)mg·L-1,耐药指数为1.37,较用药前对5-FU的敏感性提高,逆转指数为8.8(P<0.01);hct-8/FU耐药细胞PI3K、Akt、P-Akt、P-GP表达较hct-8细胞明显增加(均P<0.01),LY294002作用后其PI3K、Akt、P-Akt、P-GP表达较用药前明显下降(P<0.01)。结论:PI3K-AKT信号通路可能通过促进人大肠癌hct-8 P-GP的表达,增加其对5-FU的耐药性,降低肿瘤细胞对药物的敏感性。 |
Objective: To study the effect of the PI3K-Akt signaling pathways on P-glycoprotein(P-GP) expression and drug resistance of human colorectal carcinoma cells HCT-8/FU drug-resistant cells in vitro.Methods: MTT method was used to detect the IC50 of 5-FU and resistance index among human colorectal carcinoma cells HCT-8 cells,HCT-8/FU resistant cells and HCT-8/FU drug-resistant cell treated with PI3K-Akt channel inhibitors LY294002.Meanwhile,Western blot method was adopted to detect PI3K,Akt,P-Akt and P-GP expressions of the cell lines mentioned above.Results: The The IC50 of 5-FU was (43.2±1.4)mg·L-1 and (516.00±20.03)mg·L-1 in the colorectal carcinoma cells HCT-8 and HCT-8/FU drug-resistant cells,respectively,with a resistance index being 11.9 for the latter cells;while after HCT-8/FU drug-resistant cells were treated with drug LY294002,the IC50 of 5-FU was (58.2±4.3)mg·L-1,resistance index of 1.37,resulting a significantly increased sensitivity and a reversion index of 8.8(P<0.01);Western blot method test revealed that the expressions of PI3K,Akt,P-Akt, P-GP in HCT-8/FU drug-resistant cells increased significantly compared to those of HCT-8 cells(P<0.01),however,they significantly declined(P<0.01) followed by the LY294002 treatment.Conclusion: PI3K-Akt signaling pathways may increase the tumor cells'drug resistance to 5-FU and reduce their sensitivity to 5-FU through improving P-GP expression. |
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