RESUMEN
Objective To investigate the effect and its mechanism of targeted inhibition of the expression of chemokine receptor 4(CXCR4) gene by small interfering RNA (siRNA) on the invasion and proliferation of nasopharyngeal carcinoma cells.Methods Forty-two nasopharyngeal carcinoma tissue and its adjacent tissues in the First Affiliated Hospital of Xinxiang Medical University from January 2014 to December 2016 were collected.The expression of CXCR4 mRNA and protein in nasopharyngeal carcinoma tissue and its adjacent tissues were detected by real time-polymerase chain reaction and Western blot.The human nasopharyngeal carcinoma cell line CNE-2Z were divided into blank control group,negative control group and CX-CR4 transfection group.The cells in blank control group were not given any treatment;the cells in negative control group were transfected nonsense siRNA sequence;the cells in CXCR4 transfection group were transfected CXCR4 targeting siRNA sequence.The protein expression of CXCR4,matrix metalloproteinases-2 (MMP-2),MMP-9,β-catenin,Cyclin D1 were detected by Western bloting after 48 h of transfection.The proliferation and invasion ability of the cells were detected by cell counting kit and Transwell chamber.Results The expression of CXCR4 mRNA in nasopharyngeal carcinoma tissue and adjacent tissues was 5.526 ±0.143,0.953 ±0.091 respectively;the expression of CXCR4 protein in nasopharyngeal carcinoma tissue and adjacent tissues was 0.522 ± 0.047,0.053 ± 0.011 respectively.The expression of CXCR4 mRNA and protein in nasopharyngeal carcinoma tissue were significantly higher than those in adjacent tissues (P ＜ 0.05).The protein expression of CXCR4,MMP-2,MMP-9,β-catenin,Cyclin D1 in cells,cell survival rate and the number of cell invasion in CXCR4 transfection group were significantly lower than those in the blank control group and negative control group (P ＜ 0.05);however,there was no significant difference in above indexes between the blank control group and negative control group (P ＞ 0.05).Conclusion Inhibiting of CXCR4 gene expression in nasopharyngeal carcinoma CNE-2Z cells can significantly decrease the proliferation and invasion ability of cancer cells,and the mechanism may be related to down regulation of Wnt/β-catenin signaling pathway.