Fig. 3

ROR2 enhances resistance of melanoma cells to BH-3 mimetics. A ROR2 overexpression increased cell survival in melanoma cells upon treatment with BH-3 mimetics. A375-empty, A375-ROR2, UACC903-empty, and UACC903-ROR2 were treated with 5 µM ABT-737 and 5 µM TW-37 for 48 h, and a crystal violet cytotoxicity assay was performed. Bar graph shows the mean ± SD (n = 3) of the percent of cytotoxicity. The percentage of cytotoxicity was calculated as the quotient between the number of cells in treated wells and the number of cells in nontreated wells times 100. B ROR2 silencing enhances cell death induced by BH-3 mimetics. The experiment was performed as in A using M2-scramble, M2-shROR2, MeWo-scramble, and MeWo-shROR2 cells treated with 10 µM ABT-737 and 5 µM TW-37. C ROR2 silencing enhances cell death induced by a Bcl2-specific BH-3 mimetic. The experiment was performed as in A using A375-empty, A375-ROR2, MeWo-scramble, and MeWo-shROR2 cells treated with 10 µM venetoclax. D, E ROR2 regulates expression of Bcl2-family proteins. Protein extracts from A375-empty and A375-ROR2 (D) and M2-scramble and M2-shROR2 (E) were probed with the indicated antibodies. β-Actin were used as loading control. The blots displayed are representative of three independent experiments. The graphs show the mean ± SD of each protein’s levels normalized to the corresponding loading control and expressed as the fold change (FC) relative to the corresponding control cell line (empty or scramble). Statistical significance was tested by a one-tailed Student’s t-test or ANOVA (MeWo), ***p < 0.0001, n = 3