Figure 4

STC-1 promoted VEGF expressing through PKCβII signaling pathway. (A) VEGF expression in the different culture supernatants. ELISA assay was used to detect VEGF expression in the culture supernatants. (B) Time courses of PKCβIIand ERK1/2 avtivation induced by STC-1. BGC823 were treated with 50 ng/mL STC-1 for 15, 30, 45, 60 min. Whole- cell lysates were prepared and immunoblotted with antibodies to phosphor-PKC βII, total PKC βII, phosho-ERK1/2 and total ERK1/2. (C) Concentration courses of PKC βIIand P38 activation induced by STC-1. BGC823 were treated with different concentrations STC-1 for 45 min. Whole- cell lysates were prepared and immunoblotted with antibodies to phosphor-PKC βII, total PKC βII, phosho-P38 and total P38. The results are representative of three independent experiments. (D) Concentration courses of ERK1/2 activation induced by STC-1. BGC823 were treated with different concentrations STC-1 for 45 min. Whole- cell lysates were prepared and immunoblotted with antibodies to phosho-ERK1/2 and total ERK1/2. The results are representative of three independent experiments. (E) Effect of STC-1 on VEGF is mediated through PKCβII and ERK1/2 signaling. BGC823 was exposed to either CGP53353 (0.5 μM) or PD98059 (25 μM) for three hours and then individually with STC-1 for 24 h. The results are representative of three independent experiments. VEGF expression in BGC823 cell culture supernatants was determined by ELISA. (F) CGP53353 and PD98059 could inhibit PKC βIIand ERK activation, respectively.