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 (α₃β₁, α₄β₁ and α₅β₁), 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 α₃β₁ and α₅β₁, but little α₄β₁, while GOTO expressed a large amount of α₄β₁ as well as α₅β₁. SK-N-DZ was undetectable in any of these molecules, but expressed α_vβ₁, which was identified by immunoprecipitation and immunoblotting. Polyclonal antibody to α_vβ₃ 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.