Fig. 5.

Human osteosarcoma cell lines vary in sensitivity to Smac mimetics +/− TNFα in vitro. Parental (a) or luciferase-expressing (b) human osteosarcoma cell lines were incubated for 48 h in media containing 0, 1, 10, 100 or 1000 pg/ml human (a, b) or murine (b) TNFα and/or 3 μM GDC-0152 (“G”) or 3 μM LCL161 (“L”). Residual ATP was quantitated using CellTiter-Glo (n = 3 +/− SEM). (b) T tests with Holm-Sidak corrections for multiple comparisons were used to determine the likelihood that random chance accounted for the differences observed between responses to human versus murine TNFα, for each cell line alone or in conjunction with GDC-0152 or LCL161. (*** P < 0.001; ** P < 0.01; * P < 0.05; ns P > 0.05; n = 3, +/− SEM). The numbers above the P value data indicate the ratio of luminescence (as a surrogate for survival) of cells treated with each concentration of murine versus human TNFα, alone and together with the Smac mimetics