利用RNA干扰抑制CXCR4基因表达对乳腺癌细胞转移和侵袭能力的影响

目的探讨抑制趋化因子受体CXCR4基因对乳腺癌细胞转移和侵袭能力的影响。方法将人乳腺癌细胞株MDA-MB-31分为未干扰组、CXCR4干扰组、B-actin干扰组和空白载体干扰组。设计并合成了针对CXCR4基因的发夹式siRNA模板,体外合成siRNA表达框架（siRNA expression cassettes,SECs）,经脂质体转染CXCR4干扰组细胞,采用Western blot免疫印迹法和逆转录聚合酶链反应检测各组的抑制效果,用Biocdat Mamgel侵袭能力检测仪检测MDA-MB-231细胞的转移侵袭能力。结果SECs在mRNA水平和蛋白水平均明显抑制CXCR4基因的表达。CXCR4表达被抑制后,癌细胞侵袭能力受到明显抑制,与未干扰组相比,差异有统计学意义（P〈0．05）。结论SECs可以高效特异地抑制人乳腺癌细胞中CXCR4基因的表达。CXCR4基因高表达与乳腺癌细胞的转移密切相关,抑制细胞中CXCR4的表达可以抑制乳腺癌细胞转移和侵袭能力。

The effects of CXCR4 inhibited by RNA interference on metastasis and invasion of breast cancer cell in vitro

OBJECTIVE: To explore whether the inducible knockdown of endogenous CXCR4 gene expression in breast cancer cells can inhibit the migration significantly in vitro. METHODS: The hairpin siRNA templates were designed and the siRNA expression cassettes (SECs) were generated. In vitro the SECs were transfected into MDA-MB-231 cells using the agent siPO2RTTMXP21. The non-transfected cells were taken as control. The inhibitory effect of siRNAs was detected by RT-PCR and Western blot. The invasion ability of breast cancer cell was assayed in 24-well Biocoat Matrigel invasion chambers. RESULTS: The endogenous CXCR4 gene expression could be specifically knocked down by the SECs detected with both RT-PCR and Western blot. After the inducible knockdown, the invasion of the breast cancer cell in CXCR4 group was significantly inhibited compared with that of controls (P < 0.05) CONCLUSIONS: It is showed that inducible knockdown of endogenous CXCR4 gene expression in breast cancer cells can result in significant inhibition of breast cancer cell migration in vitro. Overexpression of CXCR4 is raleted with the migration of breast cancer cells.