Figure 8.

AA starvation-induced VEGF expression is dependent on COX-2 expression. U87 cells were subjected to AA starvation for the indicated times after transient transfection with siRNA against control (siCTRL) or COX-2 (siCOX). COX-2 and VEGF mRNA levels were determined at each time point by real-time PCR. (A) COX-2 and (B) VEGF mRNA expression at 0, 2 and 6 hours post-starvation (0h, 2h and 6h) in siCTRL and siCOX cells are shown relative to values from siCTRL cells that have not undergone starvation (0h, arbitrarily set at a value of 1). * indicate statistically significant (p < 0.05) differences by paired t-test compared with the corresponding siCTRL time points. (C) Relative reduction in VEGF mRNA expression is shown expressed as a ratio of values from siCOX to siCTRL cells. # indicate statistically significant reduction in VEGF expression by paired one-tailed t-test at each time point. Graphs show the average value of four independent experiments with error bar representing ± one SEM.