Figure 3.

Overexpression of MIB2 enhances the anti-apoptotic activity of glioma cells. (A) Overexpression of MIB2 in the glioma T98G cell line. α-Tubulin was used as the loading control. (B) Overexpression of MIB2 inhibits cell death induced by UV irradiation. MIB2-overexpressing glioma cell lines were treated by UV irradiation (20 and 40 J/m²), and viable cells were counted using the trypan blue exclusion assay. Data are presented as the mean ± standard error of the mean of three experiments with statistical significance determined by one-way analysis of variance with Tukey's post hoc test. **P<0.01. (C) MIB2 reduces UV-induced apoptosis of glioma cells. MIB2-overexpressing glioma cell lines were treated with UV irradiation (40 J/m²), followed by Annexin V-fluorescein isothiocyanate and PI staining, and the number of Annexin V+/PI-cells was counted from 5 random fields. Results are expressed as percentages of total cells. Student's t-test was used for statistical analysis. **P<0.01. (D) MIB2-overexpressing glioma cell lines were treated with UV irradiation (40 J/m²) and harvested for cell lysate preparation. Western blotting was performed to assess the levels of cleaved caspase-3 and Bcl-2 protein. α-Tubulin was used as the loading control. UV, ultraviolet; MIB2, E3 ubiquitin-protein ligase; PI, propidium iodide; Bcl-2, B-cell lymphoma 2.