Fig. 2.

Effect of MAPK inhibitors on the differentiation marker mRNAs in SaOS-2 cells. SaOS-2 cells were cultured for 7 days in complete αMEM containing 10% FBS. Then, the cells were changed with or without fresh αMEM + 10% FBS culture medium and then incubated for 12 h. Thereafter the cells were treated with PD98059 or SB203580 for 24 or 48 h; and their total RNA was analyzed by real-time RT-PCR for type I collagen (a), ALP (b), osteocalcin (c), and BMP-2 (d) mRNA. The data from a typical experiment are presented; similar results were obtained in 3 separate experiments. Asterisks indicate significance at *p < 0.05 and **p < 0.01. The house-keeping gene GAPDH served as an internal control