阿霉素对人乳腺癌细胞中PDCD4和PTEN蛋白表达的影响

Effect of Doxorubicin on the expression of PDCD4 and PTEN proteins in human breast cancer cells

目的探讨阿霉素对人乳腺癌细胞MCF-7中程序性细胞凋亡因子4(PDCD4)和磷酸酶及张力蛋白同源物(PTEN)蛋白表达的影响及微小RNA(miR)-21对其的调控。方法第一步采用浓度分别为2.5、5、10μmol/L的阿霉素处理MCF-7细胞株,CCK-8法检测阿霉素对MCF-7细胞的增殖抑制作用,采用实时荧光定量PCR的方法检测其miR-21的表达。采用免疫印迹法(Western Blot)检测PDCD4和PTEN蛋白的表达。第二步MCF-7细胞转染miR-21,未转染MCF-7细胞作为对照组,用免疫印迹法检测PDCD4和PTEN的表达。结果5μmol/L组、10μmol/L组的miR-21表达量、细胞存活率低于DMSO组,差异有统计学意义(P<0.05);10μmol/L组的miR-21表达量、细胞存活率低于5μmol/L组,差异有统计学意义(P<0.05)。随着阿霉素浓度的升高,PDCD4和PTEN蛋白的表达量明显上升。MCF-7细胞转染miR-21后,细胞中的PDCD4和PTEN蛋白的表达量低于对照组。结论在乳腺癌MCF-7细胞中,通过miR-21的调控,影响其靶基因PDCD4和PTEN蛋白的表达而发挥抑制肿瘤细胞增殖的作用。

Objective To investigate the effect of Doxorubicin on the expression of programmed apoptosis factor 4(PDCD4)and phosphatase and tension protein homologue(PTEN)in human breast cancer cells MCF-7 and the regulation of microRNA(miR)-21.Methods In the first step,MCF-7 cell lines were treated with Doxorubicin at concentrations of 2.5,5 and 10μmol/L respectively.The anti-proliferative effect of Doxorubicin on MCF-7 cells was assessed by CCK-8 method.The expression of miR-21 was detected by real-time fluorescence quantitative PCR.Western Blot was used to evaluate the expression of PDCD4 and PTEN proteins.In the second step,MCF-7 cells were transfected by miR-21 and non-transfected cells were used as the control group.The expressions of PDCD4 and PTEN were detected by Western Blot.Results The expressions of miR-21 and cell survival rate in the 5μmol/L and 10μmol/L groups were lower than those in the DMSO group,and the differences were statistically significant(P<0.05).The expressions of miR-21 and cell survival rate in the 10μmol/L group were lower than those in the 5μmol/L group,and the differences were statistically significant(P<0.05).With the increase of Doxorubicin concentration,there was a significant increase in the expression of PDCD4 and PTEN proteins.After being transfected with miR-21,the expression levels of PDCD4 and PTEN proteins in the MCF-7 cells were lower than those in the control group.Conclusion In breast cancer MCF-7 cells,miR-21 regulates the expression of target genes PDCD4 and PTEN,thereby inhibiting tumor cell proliferation.