缺氧诱导因子-2α对乳腺癌细胞多药耐药的影响

Effect of hypoxia inducible factor-2α induce multidrug resistance in breast cancer

目的探讨缺氧诱导因子-2α(HIF-2α)对乳腺癌细胞多药耐药表型的影响及其意义。方法将人低转移乳腺癌MCF-7细胞分为对照组、常氧组和缺氧组,常规培养各组细胞,采用Co Cl2处理并建立细胞缺氧模型。通过实时荧光定量聚合酶链反应和Western blot法检测各组细胞中HIF-2αmRNA和蛋白的表达,体外药物敏感试验检测缺氧状态下乳腺癌MCF-7细胞对化学治疗药物的敏感性;流式细胞术检测化学治疗药物在常氧组和缺氧组细胞内的蓄积、潴留及药物泵出率,并检测阿霉素诱导常氧组和缺氧组细胞的凋亡情况。结果缺氧组人低转移乳腺癌MCF-7细胞中HIF-2αmRNA和蛋白相对表达量均高于常氧组和对照组(P <0. 05),常氧组人低转移乳腺癌MCF-7细胞中HIF-2αmRNA和蛋白相对表达量与对照组比较差异无统计学意义(P> 0. 05)。缺氧组紫杉醇、阿霉素及氟尿嘧啶的半抑制浓度(IC50)显著高于常氧组(P <0. 05)。与常氧组比较,缺氧组人低转移乳腺癌MCF-7细胞内阿霉素的蓄积和潴留显著降低(P <0. 05),药物泵出率显著增高(P <0. 05)。阿霉素诱导下,缺氧组和常氧组人低转移乳腺癌MCF-7细胞凋亡指数分别为(68. 50±0. 93)%和(93. 50±0. 65)%,缺氧组人低转移乳腺癌MCF-7细胞凋亡指数低于常氧组(P <0. 05)。结论缺氧状态下HIF-2α可能通过降低化学治疗药物的潴留和蓄积、减少细胞凋亡而降低乳腺癌细胞对化学治疗药物的敏感性。

Objective To investigate the effect and significance of hypoxia inducible factor-2α （HIF-2α） induce multidrug resistance in breast carcinoma.Methods The breast cancer MCF-7 cells were divided into control group,normoxia group and hypoxia group.The cells were cultured with traditional method and hypoxic cellular model was established by treated with CoCl 2.The expressions of HIF-2α mRNA and protein of the cells in each group were detected by real-time quantitative polymerase chain reaction and Western blot.The sensitivity of MCF-7 cells to chemotherapeutic drugs under hypoxia condition was detected by drug sensitivity test in vitro .The accumulation and retention of chemotherapeutic drugs in the normoxia group and hypoxia group was detected by flow cytometry assay and the index of drug release was calculated.The effect of hypoxia on the apoptosis of breast cancer cells induced by adriamycin amycin normoxia group and hypoxia group was detected by flow cytometry.Results The expression levels of HIF-2α mRNA and protein in hypoxia group were significantly higher than those in normoxia group and control group （ P 〈0.05）.There was no significant difference in the expression levels of HIF-2α mRNA and protein between the normoxia group and control group （ P 〉0.05）.The half maximal inhibitory（IC 50 ） value of paclitaxel,doxorubicin,and fluorouracil in the hypoxia group was significantly higher than that in normoxia group （ P 〈0.05）.Compared with the normoxia group,the accumulation and retention of doxorubicin in MCF-7 cells in the hypoxia group was significantly lower and the index of drug release was significantly higher （ P 〈0.05）.The apoptosis index of MCF-7 cells induced by doxorubicin in the hypoxia group and normoxia group was （68.50±0.93）% and （93.50±0.65）%.The apoptosis index of MCF-7 cells in the hypoxia group was significantly lower than that in normoxic group （ P 〈0.05）.Conclusion HIF-2α may reduce the sensitivity of breast carcinoma cells to chemotherapeutic drugs by reducing the retention and accumulation of chemotherapeutic drugs and cell apoptosis under hypoxia.