Figure 3.

Effects of a PLA₂ inhibitor, mepacrine, and MEK inhibitor, PD98059, on PA-induced ERK1/2, STAT3 (Ser⁷²⁷) phosphorylation, and Bcl-2 expression in HeLa cells. (A) RNA was extracted from cells pretreated with 50 µM mepacrine for 30 min, followed by stimulation with 50 µM PA for 30 min and Bcl-2 mRNA was amplified by RT-PCR. HeLa cells were pretreated with 50 µM mepacrine for 30 min, followed by stimulation with 50 µM PA for 15 min. Cell lysates were analyzed by immunoblotting with anti-ERK1/2, anti-STAT3, and phospho-ERK1/2, phospho-STAT3 (Ser⁷²⁷) antibodies. In the case of Bcl-2 Western blotting, cells were pretreated with 50 µM mepacrine for 30 min, followed by stimulation with 50 µM PA for 3 h. Cell lysates were analyzed by immunoblotting with Bcl-2 antibody. (B) RNA was extracted from cells treated with 50 µM PD98059 for 1 h, followed by stimulation with 50 µM PA for 30 min and Bcl-2 mRNA was amplified by RT-PCR. HeLa cells were pretreated with 50 µM PD98059 for 1 h, followed by stimulation with 50 µM PA for 15 min. Cell lysates were analyzed by immunoblotting with anti-ERK1/2, STAT3, and phospho-ERK1/2, STAT3 (Ser⁷²⁷) antibodies. In the case of Bcl-2 Western blotting, cells were pretreated with 50 µM PD98059 for 1 h, followed by stimulation with 50 µM PA for 3 h. Cell lysates were analyzed by immunoblotting with Bcl-2 antibody. The relative quantities of each protein band, normalized to control cells, were quantified using Quantity One software (Bio-Rad).