Gamma secretase inhibitor-I exerted cytotoxic effects on malignant glionm cell lines by inducing cell cycle arrest and apoptosis / 中华神经医学杂志

ABSTRACT

Objective To investigate the role of gamma secretase inhibitor-I (GSI-I) in cell proliferation and apoptosis of human glioma cell lines U87 and U251.Methods RT-PCR and fluorescent quantitative RT-PCR (qRT-PCR) were employed to evaluate the expressions of Notch receptors and their target gene Hes-I in both U87 and U251 cells treated by GSI-I,respectively.Then,MTT assay was used to examine the effects of GSI-I on cell proliferation of the 2 glioma cells.Meanwhile,flow cytometry technique was also employed to detect the cell cycle changes and apoptosis induced by GSI-I treatment.Results The activity of Notch pathway was inhibited by GSI-I treatment through down-regulating the expression of Notch receptors target gene Hes-I in both U87 and U251 cells.Treatment with 2.5μmol/L GSI-I or above concentrations could significantly induce the cell cycle arrest of U87 and U251 cells and these effects were positively concentration-dependent.Flow cytometry technique showed that GSI-I inhibited the cell proliferation by inducing the cell cycle arrest of U87 cells at GI phase and inducing the apoptosis of U251 cells.Conclusion GSI-I can dramatically inhibit the cell proliferation and induce the apoptosis of U87 and U251 cells,providing a reliable evidence for clinical glioma treatment.