Résumé
This study was aimed to investigate the effect of down-regulating the CXCR4 expression on cell cycle and cell apoptosis of human T-ALL Jurkat cells. The CXCR4 specific siRNA plasmid vector was constructed and then transfected into the cultured Jurkat cell line by DMRIE-C. The expression of CXCR4 mRNA was detected by RT-PCR, the cell distribution in cell cycle and cell apoptosis were determined by flow cytometry. The experiments were divided into 3 groups: group A (blank control), group B (non-silencing dsRNA as negative control) and group C (CXCR4 siRNA). The results showed that the expression level of CXCR4 mRNA in Jurkat cells transfected with CXCR4 siRNA (group C) decreased and cell proportion in G(0)/G(1) phase increased as compared with group A (56.9% +/- 1.4% vs 68.3% +/- 2.4% and 35.8% +/- 1.9% vs 18.1% +/- 1.2% respectively) (p < 0.01), cell proportion in G(2)/M and S phase decreased as compared with group A (19.8% +/- 1.7%, 44.4% +/- 2.1% vs 27.2% +/- 1.5%, 54.7% +/- 2.8% respectively) (p < 0.01). The apoptosis rate of Jurkat cells in group C increased as compared with group A (20.9% +/- 2.0% vs 3.13% +/- 0.9% respectively) (p < 0.01), and the comparison between group A and B showed no statistical difference. It is concluded that the CXCR4 specific siRNA can effectively down-regulate the CXCR4 mRNA expression, which induces the cell apoptosis and cell cycle arrest, thereby inhibits the Jurkat cell proliferation.