siRNA抑制Ki-67表达对乳腺癌MCF-7／ADR细胞阿霉素耐药性的研究

目的采用Ki-67RNA表达载体干扰沉默Ki-67基因，检测其对乳腺癌MCF-7／ADR细胞株耐-67mRNA及蛋白表达的影响，观察沉默艇-67基因前后乳腺癌细胞株对阿霉素敏感性改变。方法体外合成靶向艇-67siRNA表达载体，应用脂质体法瞬时转染尉-67高表达的乳腺癌细胞株MCF-7／ADR，应用RT-PCR和Western印迹法检测转染后Ki-67mRNA及蛋白的表达，MTT法检测细胞增殖活性及转染前后细胞对阿霉素敏感性的变化。结果Ki-67siRNA载体转染后24h可显著抑制乳腺癌MCF-7／ADR细胞株的Ki-67mRNA和蛋白表达及细胞的增殖活性。Ki-67siRNA组阿霉素IC50值为（6．3±0．9）μg/ml。结论si—Ki-67能够有效抑制Ki-67基因的表达，降低乳腺癌细胞的增殖能力，沉默Ki-67表达能部分逆转阿霉素耐药现象。

Effects of silencing Ki-67 expression by siRNA on the adriamycin resistance of breast cancer cell line MCF-7/ADR

Objective To investigate the effect of Ki-67 siRNA on doxorubicin resistance of human breast cancer cell line MCF/ADR.Methods siRNA targeting to Ki-67 was synthesized in vitro,then Ki-67 siRNA was transfected to breast cancer MCF-7/ADR cells with liposome.The expressions of Ki-67 mRNA and protein were detected by RT-PCR and Western blotting respectively.The cell proliferation and the measured by MTT method after Ki-67 siRNA transfection.Results Transfection of Ki-67 siRNA significantly inhibited cell proliferation and expression of Ki-67 mRNA and protein expression of MCF-7/ADR cells.The IC₅₀ value of ADM in Ki-67 siRNA-transfected cells was（6.3±0.9）μg/ml.Conclusion Transfection of Ki-67siRNA can inhibit cell proliferation and Ki-67 gene expression in MCF-7/ADR cells,resulting in partial reverse of doxorubicin resistance.