Fig. 4

The expression level of AR was correlated with TMZ resistance in GBM cell lines. a-b The expression levels of AR in each GBM cell lines were evaluated by using quantitative real-time PCR and Western blot analysis. c Cells were treated with increasing concentrations of TMZ for 24 h, and then cell viability was determined by XTT assay. d The protein levels of AR in DBTRG-05MG/shControl, DBTRG-05MG/shAR#1, and DBTRG-05MG/shAR#2 cells were examined using Western blot. e Cells were exposed to increasing concentrations of TMZ for 48 h, and subsequently cytotoxicity was evaluated by an XTT-based assay. The percentage of cell viability is shown relative to untreated controls. *P < 0.05 compared with shControl group. f The cleaved PARP and cleaved caspase-3 were analyzed by Western blot. g-h The expression of AR in U87MG-S (TMZ-sensitive) and parental U87MG was evaluated by Western blot analysis. Cells treated with TMZ (1000 μM) for 24 h, and cell viability was measured by XTT assay. *P < 0.05 compared with U87MG cells. i U87MG cells were cultured in serum withdrawal medium for 24 h, and the effect of serum starvation on AR expression was analyzed by Western blot. Data are representative of at least 3 independent experiments performed in triplicate