Fig. 5

Inhibition of BIRC5 sensitizes KGN cells to TRAIL-induced apoptosis following mitochondrial membrane depolarization. Gene expression analysis of MDR1, DR4, DR5, and BIRC5 following treatment with FCCP and/or TRAIL. a Expression of the ATP dependent efflux pump, MDR1, which conveys multidrug resistance, was downregulated following all treatment conditions, asterisks indicate significance with regard to vehicle treated cells- P < 0.05* and P < 0.01**. b DR4 was significantly upregulated by treatment with TRAIL alone, but the secondary receptor for TRAIL, DR5 (c), showed no change in expression (P = 0.42). d The negative regulator of apoptosis, BIRC5, was significantly upregulated following treatment with TRAIL, however when pretreated with FCCP this response was lost. e A knockdown of BIRC5 (64.0 ± 3.3% mRNA expression, 48 h post treatment, n = 3, P < 0.01**) prior to treatment (f) led to a significant enhancement of apoptosis induction by dual treatment with FCCP and TRAIL