Effects of CXCR4 gene silencing by lentivirus shRNA on proliferation of the EC9706 human esophageal carcinoma cell line.

CXCL12/CXCR4 has been studied as an important biomarker for many human malignancies, but studies are limited for esophageal squamous cell carcinoma (ESCC). In this study, an effective RNAi sequence targeting the CXCR4 gene was selected, a lentiviral shRNA vector was constructed to specifically silence CXCR4 expression in the EC9706 ESCC cell line, and the effects of CXCR4 silencing on cell growth in vitro and tumour growth in nude mice were then evaluated. The expression of CXCR4 in EC9706 was significantly downregulated after transfection with a lentiviral shRNA vector. The expression of the apoptosis-related gene Bcl-2 was decreased. In addition, after CXCR4 inhibition, cell growth was considerably inhibited, increased apoptosis in the EC9706 cells was found, the G0/G1 percentage was significantly increased, and the number of cells in S phase was reduced. Moreover, tumour growth in nude mice was inhibited. In conclusion, the downregulation of CXCR4 expression by transfection with a lentiviral shRNA vector in ESCC cells could inhibit tumour proliferation. Our data may provide an avenue for finding new ESCC treatments.