Fig. 4.

BRAF V600E promoted GABP binding to mutant TERT promoter by upregulating GABPB. a Chromatin-immunoprecipitation (ChIP) assay for GABPA and GABPB occupancy at TERT promoter in K1 and A375 cells with TERT promoter mutation and in WRO and HTORI3 cells without promoter mutation. IgG was used as negative control. b Co-immunoprecipitation (Co-IP) analysis of the interaction of GABPA with GABPB in K1 cells. c ChIP assay for GABPA occupancy at TERT promoter in K1 and A375 cells with or without stable BRAF knockdown. d Western blotting analyses of GABPA, GABPB, and beta-actin in K1 and A375 cells with/without stable BRAF knockdown. e Luciferase reporter assays for GABPA and GABPB promoters in A375 cells with or without stable BRAF knockdown. Scramble shRNA was used as control. *P < 0.05, ***P < 0.001, by two-tailed Student’s t test. n.s. not significant. All the values represent the average ± standard deviation (SD) of triplicate samples and similar results were obtained in at least two independent experiments