Synthesis and angiogenetic activity in the chick chorioallantoic membrane model of thymosin beta-15

Thymosin beta-15 (Tbeta15), a 44 amino acid peptide (MW = 5173) localized in human prostate and breast cancer tissues was successfully synthesized in multigram quantities using Fmoc solid-phase peptide synthesis. The synthesized product was shown to have the right structure by ESI and MALDI mass spectral techniques and amino acid analysis. Relatively high yield was achieved, which might be due to enhanced acid stability of the p-cyanotrityl resin used. The effect of the synthesized Tbeta15 on the angiogenesis process was investigated using the chick chorioallantoic membrane (CAM) in vivo model. At concentrations above 1 microg/10 microl per disc, Tbeta15 exhibited a positive effect on angiogenesis, comparable to the effect of the intense angiogenetic factor phorbol 12-myristate 13-acetate at a standard concentration of 0.1 microg/10 microl per disc. The results of this study contribute to the further elucidation of the biological regulatory role of thymosin peptides and provide helpful information in the investigation of their possible therapeutic potential.