多柔比星对p53缺陷细胞MDA-MB-231表达乳腺癌易感基因1和聚腺苷酸二磷酸核糖转移酶的影响

Effects of epirubicin on expression of BRCA1and PARP-1proteins in p53-deficient breast cancer cells MDA-MB-231

目的探讨阿霉素对p53缺陷乳腺癌MDA-MB-231细胞表达脱氧核糖核酸(DNA)损伤修复相关蛋白乳腺癌易感基因1(BRCA1)和聚腺苷酸二磷酸核糖转移酶(PARP-1)的影响。方法免疫印迹(Westernblot)检测不同浓度阿霉素干预后MDA-MB-231细胞表达BRCA1和PARP-1及其PARP-1活性的动态变化。结果阿霉素干预后BRCA1和PARP-1活性呈现出不同的变化:阿霉素能抑制PARP-1的活性,但当给予恢复一定时间时,PARP-1活性将有所上调(0.5、1、1.5、2μmol/L浓度下PARP-1光密度比值4.998、5.356、5.626和6.047vs对照组3.320);BRCA1表达不受时间影响,但在低浓度呈现高表达,当浓度达到2μmol/L时BRCA1表达有所下调但然高于对照组(0.784vs0.612);而PARP-1表达在整个过程中基本无变化,随着阿霉素浓度提高,其断裂有所增加;阿霉素能诱导MDA-MB-231细胞凋亡,在2μmol/L浓度时细胞凋亡率增加至6.2%,差异有统计学意义(P<0.01)。结论阿霉素持续作用能抑制人MDA-MB-231乳腺癌细胞的PARP-1活性,但一定恢复时间能增强PARP-1活性;阿霉素对BRCA1蛋白表达影响呈现先增加后减少的趋势。

Objective To study the effects of epirubicin on expression of breast cancer associated 1 （BRCA1） and poly （ADP-ribose） polymerase （PARP-1） proteins in p53-deficient breast cancer cells MDA-MB-231. Methods During different periods of time after the cells treated with epirubicin, the expression level of BRCA1 an PARP-1 proteins were detected by western blotting. Results BRCA1 and PARP-1 showed different changes after treatment with epirubicin. Epirubicin could inhibit the activity of PARP-1, giving some recovery times the activity of PARP-1 would increase（in the concentration of 0.5,1,1.5,2 μmol/L of epirubicin, the optical density of PAR was 4. 998, 5. 356,5. 626,6. 047 vs control 3. 320;the expression of BRCA1 performed the trend of first increase then decrease, in 2 μmol/L group,BRCA1 was less than the front concentration groups but more than control group（0. 784 vs 0. 612）. Epirubicin did not effect the expression of PARP 1, but with the increase of the concentration of the epirubicin, the PARP 1 cleavage fragments were more obvious. Epirubicin could induce MDA-MB 231 cells apoptosis,in the 2 μmol/L concentration,cell apoptosis rate was 6.2% （ P d0.01）. Conclusion Continued treatment of epirubicin can inhibit the activity of PARP-1 ,the short time of recovery can increase the activity of PARP-1 in breast cancer cells MDA-MB-231. The expression of BRCA1 shows the trend of increase first then decrease after being treated with epirubicin.