Abstract:OBJECTIVE: To study the effect of endogeneous gangliosides (Gls) on integrin α2β1-mediated adhesion of neuroblastoma cells to collagen (Col). METHODS: Neuroblastoma SK-N-SH cell line was cultured in the modified eagle's medium with the presence of 10 μm D-threo-1-phenyl-2-decanolamino-3-morphinolin-1-propanol (D-PDMP), an inhibitor of glucosylceramide synthase. Flow cytometry was used to detect the expression of integrin α2β1 in the cell line. The effects of Mg2+ and monoclonal antibodies to integrin α2β1 on the adhesion of the cell line to immobilized Col were observed. The adhesion cell number was measured with the BCA method and presented with absorptance A570. RESULTS: There was a high expression of integrin α2β1 in the SK-N-SH cell line without D-PDMP treatment. Endogenous Gls in the cells were almost depleted after 6-day exposure to D-PDMP, but the integrin α2β1 expression was not significantly changed. 1 mmoL/L Mg2+ treatment increased significantly the number of adhesion cells in the SK-N-SH cell line. The adhesion to Col of the SK-N-SH cells exposed to D-PDMP which Gls was depleted was significantly reduced compared with the control SK-N-SH cells treated with 1 mmoL/L Mg2+ (A570：0.33±0.016 vs 0.57±0.033; P<0.01). After endogeneous Gls was added into the Gls-depleted SK-N-SH cells, the adhesion of the cells was restored (A570∶0.52±0.035). The adhesion of SK-N-SH cells was significantly blocked by anti-α2 and anti-β1 monoclonal antibodies, with A570 of 0.31± 0.018 and 0.36± 0.021 respectively. CONCLUSIONS: Endogenous tumor Gls increases neuroblastoma cell adhesion to Col by regulating the function of integrin α2β1, but has no effects on the integrin expression. It is suggested that tumor Gls may play a role in migration, invasion and metastasis of tumor cells.［Chin J Contemp Pediatr, 2007, 9 (1):42-46］
