RESUMO
Objective To explore effect of endogeneous gangliosides(Gls) and integrin ?2?1 on protein phosphotyrosine expression of pp125 focal adhesion kinase (pp125FAK) after adhesion of SK-N-SH neuroblastoma cells to collagen(Col).Methods SK-N-SH cell line with high expression of integrin ?2?1 was cultured in presence of D-threo-1-phenyl-2-decanolamino-3-morphinoline-1-propanol(D-PDMP).Effect of endogeneous Gls,anti-?2 and anti-?1 monoclonal antibody on protein phosphotyrosine expression of pp125FAK during adhesion of SK-N-SH cells to Col were determined by immunoprecipitate and Western blotting.Results After 6 days,endogenous Gls in cells were almost depleted.Gls-depletion,anti?2 and anti-?1 monoclonal antibody were able to decrease pp125FAK expression of SK-N-SH cells adherent to Col respectively.GD2,the major component of neuroblastoma cell Gls could reco-ver pp125FAK expression to a certain degree.Conclusions Endogenous tumor Gls regulate protein phosphotyrosine expression of pp125FAK during adhesion of neuroblastoma cells to Col.It is suggested that tumor Gls may increase signal transduction of tumor cell integrin ?2?1 by increasing tyrosine phosphorylation of pp125FAK.