Distinct mechanism of human neuroblastoma cell adhesion to fibronectin

We investigated the adhesion of three morphologically distinct human neuroblastoma cell lines (NCG, GOTO and SK-N-DZ) to intact fibronectin, central cell binding domain fragment (CBF) and CS peptide-IgG conjugates in the fibronectin molecule. Each cell line was found to express different integrin fibronectin receptors (alpha 3 beta 1, alpha 4 beta 1 and alpha 5 beta 1), although similarly attached on intact fibronectin. To CBF, NCG attached well, while GOTO moderately and SK-N-DZ poorly attached. Only GOTO adhered to CS1-IgG. RGDS inhibited the spreading of NCG and SK-N-DZ on intact fibronectin, but it barely inhibited that of GOTO. The analysis by fluorescence-activated cell sorting (FACS) revealed that NCG expressed abundant alpha 3 beta 1 and alpha 5 beta 1, but little alpha 4 beta 1, while GOTO expressed a large amount of alpha 4 beta 1 as well as alpha 5 beta 1. SK-N-DZ was undetectable in any of these molecules, but expressed alpha v beta 1, which was identified by immunoprecipitation and immunoblotting. Polyclonal antibody to alpha v beta 3 inhibited the adhesion of SK-N-DZ but not that of NCG or GOTO on intact fibronectin. These results suggest the existence of a distinct mechanism of cell adhesion to fibronectin among human neuroblastoma cell lines. It remains to be determined if such heterogeneous adhesion properties are related to the unique metastatic character of human neuroblastoma.