BackgroundInformation | VEGF(Vascularendothelialgrowthfactor,VEGFA,VEGF-A),adimericligand,isamongthemostpotentangiogenicmitogens.VEGFissecretedbytumorcellsandothercellsexposedtohypoxia.VEGFisahighlyspecificmitogenforvascularendothelialcells.SevenVEGFisoforms(a,b,c,d,e,f,g)aregeneratedasaresultofalternativesplicingfromasingleVEGFgene.ThemostcommonlystudiedisoformsareVEGF121,VEGF165,andVEGF189(f,dandb,respectively)AllsevenisoformsdifferintheirmolecularmassandinBIOLOGicalpropertiessuchastheirabilitytobindtocell-surfaceheparan-sulfateproteoglycans.TheexpressionofVEGFispotentiatedandissecretedbytumorcellsinresponsetohypoxia,byactivatedoncogenes,andbyavarietyofcytokines. |