survivin—siRNA联合化疗药物对乳腺癌MCF-7细胞凋亡及逆转耐药的研究

目的观察靶向survivin的siRNA联合紫杉醇和表柔比星对乳腺癌MCF-7细胞凋亡及逆转耐药的影响。方法构建靶向survivin的siRNA表达质粒，转染乳腺癌MCF。7细胞，荧光定量聚合酶链反应（PCR），Westernblot技术检测转染前后survivin基因表达的变化，CCK．8法检测靶向survivin的siRNA联合紫杉醇、表柔比星对MCF-7细胞药物敏感性的影响，利用流式细胞术检测细胞凋亡作用。结果survivin—siRNA-2能有效抑制survivinmRNA（0．30±0．03）和蛋白的表达（0．37±0．09）（P〈0．05）；紫杉醇24、48h抑制率分别为（38．5±4．0）％、（41．7±6．3）％]、表柔比星24、48h抑制率分别为（37．0±8．6）％、（40．6±12．1）％1均可抑制MCF-7细胞增殖并诱导部分细胞凋亡；当与survivin—siRNA联合时上述作用显著加强f紫杉醇24、48h抑制率分别为（76．0±2．9）％、（85．1±4．0）％；表柔比星24、48h抑制率分别为（74．6±5．6）％、（82．5±4．8）％1（P〈0．05），并且细胞抑制率呈现时间、剂量依赖性。结论利用RNA干扰阻断survivin基因表达同时联合相应化疗药物可以显著增强MCF-7细胞对药物敏感性并促进其凋亡，该方法在乳腺癌治疗中具有潜在的临床应用价值。

Study of survivin-siRNA combined with the chemotherapy drugs to enhance the breast cancer MCF-7cells apoptosis and reverse drug resistance

Objective To investigate the effects of siRNA against survivin combined with the neoadjuvant chemotherapy （paclitaxel and epirubicin） on the apoptosis in breast cancer MCF-7 cell and reverse drug resistance. Methods Molecular cloning technique was applied to construct the expression vector of siRNA against survivin, and effectene transfection reagent was used to transfect MCF-7 cell. Survivin expression was detected by qPCR and Western blot methods. The effects of paclitaxel or epirubicin combined with or without siRNA against survivin, on the drug susceptibility of MCF-7 cell were detected by CCK-8 assay and that of including MCF-7 cell apoptosis were detected by flow cytometry. Results Survivin-siRNA-2 effectively inhibited the expression of survivin mRNA （0.30±0.03） and protein （0.37±0.09） （P 〈 0.05）. Both paclitaxel IR 24, 48 h = （38.5±4.0） %, （41.7±6.3） %] and epirubicin IR 24, 48 h = （37.0±8.6） %, （40.6± 12.1） %] can suppress the proliferation of MCF-7 cell and induce its apoptosis, and siRNA against survivin combined with chemotherapy drugs enhanced both effects significantlypaclitaxel IR 24, 48 h = （76.0±2.9） %, （85.1±4.0） %; epirubicin IR 24, 48 h = （74.6±5.6） %,（82.5±4.8） %] （P 〈 0.05）. The inhibition rate of MCF-7 was concentration and time dependent. Coneluslons Blocking survivin gene expression by RNAi, and combining with the appropriate chemotherapy can significantly enhance the sensitivity of MCF-7 cell to drugs and cell apoptosis. This technology has important potential clinical value in the therapy of breast cancer.