Effects of TNFα on cell viability, proliferation and apoptosis of glioma cells U251.

PURPOSE To analyse the relationship between the expression of TNFα and the characteristics of glioma cell line U251. METHODS U251 cell line was transfected with overexpressed TNFα or depleted TNFα constructs. The cell viability, proliferation and apoptosis were determined with MTT assay and flow cytometry analysis. The expressions of TNFα, caspase or microRNA (miR) were detected by Western blot analysis or real-time PCR (RT-PCR). The activity of caspase3 was examined by the absorbance of p-nitroaniline (pNA) production. RESULTS Overexpression of TNFα could decrease cell viability, suppress cell proliferation and promote cell apoptosis, whereas knockdown of TNFα displayed the opposite effects. In addition, the effects of TNFα on the expression of caspase3, miR-9-3p, miR-9-5p, miR-17-3p, miR-17-5p, miR-31-3p and miR-31-5p were also probed. Overexpression of TNFα could raise the expression of caspase3 and miR-9 and knockdown of TNFα had an opposite effect. Our results also showed the overexpression of miR-9 could increase the expression of caspase3, while the inhibition of miR-9 had the opposite effect. CONCLUSION These results suggested that TNFα might be involved in the attenuation of growth, proliferation and promotion of apoptosis in U-251 cells by regulating the expression of miR-9 and caspase3 and that miR-17 and miR- 31 perhaps were not correlated with the apoptosis of U251 cells or not acted as important factors in mediating the apoptosis of U251 cells induced by TNFα. Furthermore, the caspase3 could be regulated by miR-9 in an indirect way.