甲基硒酸对人三阴性乳腺癌细胞的抑制和化疗增敏作用

Effects of methylseleninic acid on inhibition and chemosensitization of triple-negative breast cancer cells

目的 探讨甲基硒酸（MSA）对人三阴性乳腺癌（TNBC）的化疗增敏作用及其分子机制.方法 分别采用2.5、3.5、4.0 μmol/L的MSA联合不同浓度的紫杉醇、阿霉素与MDA-MB-231细胞株共培养,分别应用细胞计数试剂盒（CCK-8）检测化疗药物单药和联合MSA用药时细胞增殖抑制率,并通过合用指数的计算,探讨MSA对化疗药物疗效的影响；应用膜联蛋白V-异硫氰酸荧光素（Annexin V-FITC）/碘化丙锭（PI）双染法检测细胞凋亡变化；利用Western blot检测蛋白去乙酰化-6（HDAC-6）的表达.结果 不同浓度化疗药物联合MSA后细胞增殖率较单用化疗药物组均下降,呈明显的量效关系,提示MSA与化疗药物具有协同作用；MSA、紫杉醇及阿霉素对TNBC细胞均有诱导凋亡作用,10nmol/L紫杉醇联合3.5 μmol/L的MSA后细胞凋亡率由42.7％上升至60.4％（P＜0.01）,0.5μmol/L阿霉素联合3.5 μmol/L的MSA后细胞凋亡率由31.6％上升至50.8％（P＜0.05）；单用化疗药物不影响HDAC-6的表达,MSA单药及联合化疗药物处理后细胞HDAC-6的表达受到明显抑制.结论 MSA通过增强抗肿瘤药物诱导细胞凋亡作用提高了化疗药物的疗效,调节HDAC-6活性是其化疗增敏的机制之一.

Objective To investigate the effects of methylseleninic acid on chemosensitization of triple-negative breast cancer （TNBC） cells and the molecular mechanism.Methods Methylseleninic acid （MSA） （2.5,3.5,4.0 μmol/L） in combination with paclitaxel,doxorubicin or malondialdehyde （MDA）-treated MB-231 cells were cultured separately.Cell counting kit-8 （CCK-8） assay was applied to detect the inhibition of cell proliferation rate by chemotherapy drugs use alone or in combination with MSA,and the combined index was calculated to explore the impact of the function of MSA on the efficacy of chemotherapy drugs.Annexin V-FITC/propidium iodide （PI） double staining was applied to detect apoptosis,flow cytometry to examine cell cycle,and Western blotting to analyze thes histone deacetylase-6 （HDAC-6） expression.Results The cell proliferation rate of chemotherapy drugs in combination with MSA was decreased as compared with chemotherapy drugs used alone,suggesting the synergetic effects of MSA and chemotherapy drugs.The combined use of paclitaxel with MSA could significantly increase the number of cells in G2/M phase （P ＜ 0.05）,that of doxorubicin with MSA could significandy increase the number of cells in S-phase cells （P ＜ 0.05）,and the prompt MSA enhanced the effect of anticancer drugsinduced cell cycle arrest.MSA,paclitaxel and doxorubicin could induce apoptosis of TNBC cells.The apoptosis rate in MSA ＋ chemotherapy groups was significantly increased as compared with monotherapy group and the control group.Chemotherapy drugs alone did not affect the expression of HDAC-6,and MSA used alone or incombination with chemotherapy drugs could significantly inhibit the HDAC-6 expression.Conclusion MSA enhanced anticancer drugs-induced cell cycle arrest and apoptosis so as to improve the efficacy of chemotherapy drugs probably by regulating the HDAC-6 expression.