Antibody Targeting of Cathepsin S Inhibits Angiogenesis and Synergistically Enhances Anti-VEGF
Figure 1
Cathepsin S expression and activity is up-regulated by pro-angiogenic stimuli.
(A) Total RNA was isolated from endothelial cell lines (HUVEC and HMEC-1) and used to assess Cathepsin S mRNA by RT-PCR. GAPDH serves as a control. (B,C) Human recombinant VEGF (10 ng/ml) up-regulates cathepsin S mRNA and protein in HUVECs when assessed by RT-PCR and western blot using GAPDH and tubulin as respective controls (D) Human recombinant VEGF (10 ng/ml) stimulates Cathepsin S-like activity, as assessed by the cleavage of fluorigenic substrate, Cbz-Val-Val-Arg-AMC, by 37% in HUVEC cell lysates. (E,F) To demonstrate the effect of hypoxia on Cathepsin S up-regulation total RNA and protein was isolated from HUVEC endothelial cells (grown in normal or hypoxic conditions) and examined by RT-PCR and western blot. GAPDH and tubulin serves as a control.