Experimental study on anti-angiogenic activity of T7 peptide derived from active fragment of Tumstatin / 中国现代普通外科进展

ABSTRACT

Objective:To investigate the influence and related mechanisms of T7 peptide derived from tumstatin on angiogenesis in vitro.Methods:HUVECs were incubated in hypoxia chamber(37℃,1％ O2,5％ CO2,94％ N2) to simulate the hypoxic microenvironment in tumors,and grouped intohypoxia group,hypoxia+T7 peptide (1.0 μ mol/L) group,and hypoxia+T7 peptide(2.0μ mol/L) group.The tube formation assay was applied to analyze the influence of T7 peptide on angiogenesis under hypoxia.Cell Counting Kit-8 was applied to observe the cell viability.The apoptosis rate was detected with Annexin V-FITC,and the expression levels of pro-apoptotic protein BAX and anti-apoptotic protein Bcl-2 were observed with western blot.Immunofluorescence and western blot were used to detect the expression of VE-cadherin.Results:Under hypoxic condition,T7 peptide significantly inhibited capillary-like tube formation (P＜0.05),inhibited ECs viability(P＜0.05),and increased the ECs apoptosis rate in vitro;T7 peptide resulted in the downregulation of anti-apoptotic protein Bcl-2 (P＜0.01)and upregulation of pro-apoptotic protein BAX(P＜0.05);the expression of VE-cadherin was downregulated by T7 peptide significantly(P＜0.05).Conclusions:T7 peptide could execute its anti-angiogenic activity via inhibition of ECs viability,induction of ECs apoptosis rate,and downregulation of VE-cadherin expression.