Fig. 1

Inhibitory effects of PIK-75, TGX-221, CAL-101 and SP600125 on glioblastoma cell proliferation and signaling transduction. a-d U-87 MG cells were treated with PIK-75, TGX-221, CAL-101 or SP600125 at different concentrations for 48 h. DMSO was used as a carrier control. Cell viability of U-87 MG cells sharply decreased when treated with PIK-75, CAL-101 and SP600125, whereas TGX-221 had no significant inhibitory effect (n = 3; p values were determined by One-way ANOVA and Post Hoc multiple comparison Tukey HSD test. *: p <0.05; **: p <0.01; ***: p <0.001). e-g Isoform-selective PI3K inhibitors PIK-75, TGX-221 and CAL-101 dramatically inhibited Akt phosphorylation at Ser473 and Thr308. h JNK inhibitor SP600125 suppressed JNK signaling via reducing c-Jun phosphorylation, whereas JNK phosphorylation was not affected