siRNA-mediated knockdown of GABPA and GABPB1 deregulates SDHD expression in melanoma cells. A, GABPA depletion decreases SDHD and increases GABPB1 expression in three melanoma cell lines (UACC1113, UACC903, and C021). B, GABPB1 depletion increases GABPA expression in three melanoma cell lines (UACC1113, UACC903 and C021), but has little effect on SDHD levels. C, concomitant depletion of both GABPA and GABPB1 decreases SDHD expression in both UACC1113 and UACC903 cell lines.