Abstract
OBJECTIVE: To detect CCR5 protein expression in different human tongue squamous cell carcinoma cells and observe the effect of macrophage inflammatory protein-1β (MIP-1β) on the proliferation and apoptosis of CAL-27 cells. METHODS: Western blotting and immunofluorescence staining were used to detect the expression of the CCR5, the receptor of MIP-1β, in 3 human tongue squamous cell carcinoma cells UM-1, CAL-27, and Tca-8113. CCK-8 assay was used to assess the proliferation of CAL-27 cells stimulated with 10, 20, and 40 ng/mL MIP-1β for 12, 24, or 48 h. The apoptosis of the cells stimulated with MIP-1β (10, 20, and 40 ng/mL) for 24 h was analyzed using flow cytometry with Annexin V/PI double staining. RESULTS: CCR5 expression was detected both on the membrane and in the cytoplasm in all the 3 tongue squamous cell carcinoma cell lines. At the concentrations of 10, 20, and 40 ng/mL, MIP-1β stimulation for 12 and 24 h significantly promoted the proliferation of CAL-27 cells (P<0.05); MIP-1β stimulation for 48 h at the concentrations 10 and 20 ng/mL, but not at 40 ng/mL, promoted the proliferation of CAL-27 cells (P<0.05). MIP-1β stimulation at 40 ng/mL for 24 produced the most obvious apoptosis-inducing effect in CAL -27 cells (P<0.05), while MIP-1β at 10 or 20 ng/mL did not induce obvious apoptosis in the cells (P>0.05). CONCLUSION: CCR5 is expressed in all the 3 human tongue squamous cell carcinoma cells. MIP-1β can promote the proliferation of CAL-27 cells but high concentrations of MIP-1β also induced cell apoptosis. Prolonged stimulation of the cells with a high concentration of MIP-1β shows attenuated effect in promoting cell proliferation probably as a result of cell apoptosis induced by MIP-1β.