Figure 5.

KAI1 decreases VEGF expression. (A) PC3 cells were cotransfected with a VEGF promoter (2.2 kb)-luciferase reporter plasmid and HIF-1α and GFP-KAI1 expression plasmids. Forty-eight hours after transfection, cell lysates were analyzed for luciferase expression. (B) PC3 cells stably transfected with KAI1 (PC3-KAI1 #5 and PC3-KAI1 #6) or vector control (PC3-GFP #8) were cotransfected with a VEGF promoter-luciferase reporter plasmid and a HIF-1α expression vector. Forty-eight hours after transfection, cell lysates were analyzed for luciferase activity. (C) PC3 cells were cotransfected with a VEGF promoter-luciferase reporter plasmid and a GFP-KAI1 expression plasmid. Twenty-four hours after transfection, cells were treated with 100 μM CoCl₂ for 24 hours, and then luciferase activity was measured. (D) Total RNA from PC3 cells stably transfected with KAI1 (PC3-KAI1 #5 and PC3-KAI1 #6) or vector control (PC3-GFP #8) was isolated, and VEGF mRNA expression was analyzed by RT-PCR. (E) After treatment of si-CDCP1, PC3 cells were harvested and VEGF mRNA expression was analyzed by RT-PCR. (F). PC3 cells stably transfected with KAI1 (#6) or vector control (PC3-GFP #8) were exposed to CoCl₂ (100 μM) for 24 hours. Total RNA was extracted and mRNA levels were quantified by RT-PCR.