Survivin siRNA协同5-FU抑制MCF-7细胞的增殖

目的 研究以survivin为靶标的小干扰RNA（siRNA）与化疗药5-FU联合应用抑制MCF-7细胞增殖的作用。方法 利用T7RNA聚合酶体外转录合成siRNA并筛选出一条RNA干扰survivin基因的靶序列。以脂质体为载体，将survivin siRNA转染至人乳腺癌MCF-7细胞中，用四氮唑盐（MTT）法染色并计算siRNA联用5-FU对MCF-7细胞的抑制率，用SAS统计软件及金正均9值法进行统计分析。结果 单用5-FU处理细胞，其IC50为4．42μg／ml，而加入5nmoFLsiRNA后，其IC50降为1．18μg/ml，siRNA与5-FU联用对MCF-7细胞的抑制作用较单用5-FU明显增强（F=26．74，P〈0．01）；Q值分析表明survivin siRNA与中低浓度的5-FU联用，有较好的协同作用（0≥1．15）。结论 survivin siRNA可显著增强5-FU对MCF-7细胞增殖的抑制，提高肿瘤细胞对化疗药物的敏感性，克服耐药性的产生。

Synergism between a siRNA targeted to survivin and 5-FU in inhibiting MCF-7 cell proliferation in vitro

OBJECTIVE: To investigate the role of small interfering RNA (siRNA) targeted to survivin in combination with 5-fluorouracil (5-FU) in inhibiting the proliferation of MCF-7 cells. METHODS: A siRNA targeted to survivin was synthesized and transfected into MCF-7 cells via lipofectin. Changes of the cell growth activity in response to combined treatment with survivin siRNA and 5-FU or 5-FU treatment alone was evaluated by MTT assay. The Q method of Jin Zhenjun was used to evaluated synergism between the synthesized siRNA and 5-FU. RESULTS: Treatment with 5 nmol/L siRNA reduced the IC50 of 5-FU from 4.42 to 1.18 microg/ml, and the inhibitory effect of combined treatment on MCF-7 cells was higher than that of 5-FU alone (F=26.74, P<0.01). Synergism effect was observed between 5-FU at lower concentrations and survivin siRNA. CONCLUSION: siRNA may enhance the effectiveness of 5-FU in inhibiting the proliferation of MCF-7 cells.