Figure 4.

TGase 2 inhibition and p53 overexpression decrease vascular endothelial growth factor (VEGF) secretion under hypoxia. (A) VEGF (pg/mL) secretion into the cell culture supernatant was assessed by ELISA. Cells were treated with STN and incubated in serum-free medium under hypoxia (1% O₂) for 24 h. (B) Cells were transfected with control or TGase 2 siRNA and incubated in serum-free medium under hypoxia (1% O₂) for 24 h. VEGF levels were determined by ELISA. (C) Cells were transfected with plasmid encoding wild-type p53 cDNA and incubated in serum-free medium under hypoxia (1% O₂) for 24 h. VEGF levels were determined by ELISA. The secreted VEGF amount (absorbance) is used to normalize the sulforhodamine B assay (absorbance). Sulforhodamine B assay in cell culture to investigate cell proliferation. Error bar represents SD. GraphPad Prism software used to perform one-way ANOVA, ** p < 0.01, *** p < 0.001, **** p < 0.0001. Data are representative of three independent experiments.