1. TNFα is an important survival and growth signal for melanoma.
TNFα is an important survival and growth signal for melanoma. A, the Kaplan–Meier plot showing melanoma-free survival (%) of tamoxifen-treated BrafV600E;Tyr::CreERT2 (BrafV600E) and BrafV600E;Tnfα−/−;Tyr::CreERT2 (BrafV600E/TNFα−/−) mice and control mice (ethanol-treated BrafV600E;Tnfα−/−;Tyr::CreERT2 mice and tamoxifen-treated Tyr::CreERT2 mice). P < ; log-rank (Mantel–Cox) test. B, growth of BrafV600E-4434 melanoma allografts in WT and TNFα−/− mice. C, in vitro growth assay of BrafV600E-4434 melanoma cells treated with BSA or 50 ng TNFα once every 3 days. D, anoikis assay of BrafV600E-4434 melanoma cells for dead cells detected by trypan blue staining. Cells were cultured under nonadherent conditions for 72 hours and treated with BSA or 50 ng TNFα. A Western blot for MITF, pIκBα, cleaved caspase-3, and ERK2 is shown. E, Western blot of the indicated cell lines for MITF and pIκBα and ERK2 after 24 hours of treatment with 50 ng TNFα. F, anoikis assay for untreated or TNFα-treated 4434, A375, and 4434-MITF– and A375-MITF–overexpressing cells. G, Western blot for MITF, pIκBα, cleaved caspase-3, and ERK2 of detached A375 and A375-MITF cells treated for 48 hours with 50 ng TNFα. H, anoikis assay for untreated or TNFα-stimulated A375 cells transfected with control or MITF-specific siRNAs. A Western blot for MITF, pIκBα, cleaved caspase-3, and ERK2 is shown.
Michael P. Smith et al. Cancer Discovery 2014;4:
©2014 by American Association for Cancer Research