Fig. 3.

EGFR and HER4 are required for the HB-EGF-induced StAR expression. A and B, KGN cells were transfected with 50 nM control siRNA (si-Ctrl) or EGFR siRNA (si-EGFR) for 48 h, and then treated with 5 ng/mL HB-EGF (HB) for 24 h. The StAR and EGFR mRNA levels (A) and protein levels (B) were examined by RT-qPCR and western blot, respectively. C and D, KGN cells were transfected with 50 nM control siRNA (si-Ctrl) or HER4 siRNA (si-HER4) for 48 h, and then treated with 5 ng/mL HB-EGF (HB) for 24 h. The StAR and HER4 mRNA levels (C) and protein levels (D) were examined by RT-qPCR and western blot, respectively. The results are expressed as the mean ± SEM of at least three independent experiments. Values that are statistically different from one another (p < 0.05) are indicated by different letters