FIGURE 2.

Synergistic anti-GBM effects of C11 in combination with mTOR inhibitors. A, inhibition of mTOR inhibitor-induced IRES activity in LN229 cells. Cells transiently transfected with the indicated IRES mRNA reporter constructs were treated with rapamycin (Rapa) or rapamycin + C11 (left panel) and PP242 or PP242 + C11 (right panel), and luciferase activities were determined. The results are expressed as relative -fold change in firefly (FF) luciferase activity, and the mean ± S.D. is shown for three independent experiments. B, inhibition of GBM cell line proliferation following 48 h culture in C11. Data represent mean ± S.D. of three independent experiments. C, combination analysis of PP242 and C11 inhibitors in GBM cell lines treated with the indicated doses of PP242 alone or in combination for 48 h. Cell proliferation relative to control cultures was assessed via XTT assays. Control cells were treated with DMSO vehicle. Data are mean ± S.D. (n = 3). D, cell cycle phase distributions were determined on the indicated GBM cell lines in the absence or presence of PP242 or C11 as shown. Percent apoptotic cells as determined via annexin V-FITC staining are also shown below each graph. One of three experiments with similar results is shown. E, protein levels of cyclin D1, c-Myc, and actin in GBM lines following the indicated treatments with PP242, C11, or both compounds at 24 h. Data shown are representative of experiments repeated twice.