Glycolipid composition in bladder tumor: A crucial role of GM3 gangliosidein tumor invasion

Glycolipids were extracted from primary bladder tumors of 14 patients and 2 normal counterparts. Their expression pattern was assessed by thin-layer c hromatography (TLC). The most remarkable change was massive accumulation of GM3 in superficial bladder tumors compared with invasive tumors. This chan ge was also confirmed by immunohistochemistry using anti-GM3 monoclonal ant ibody. The activities of glycosyltransferases responsible for GM3 synthesis (GM3 synthase, Gb3 synthase and GD3 synthase) were consistent with upregul ated expression of GM3 in superficial humors. It was suggested that the mar ked GM3 accumulation in superficial tumors was caused not only by upregulat ed GM3 synthase but also by downregulated activities of Gb3 and GD3 synthas e. Histopathologic examination revealed an inverse correlation of the amoun t of GM3 expressed with invasive potential. Exogenously supplemented GM3 su ppressed invasion potential in human bladder tumor cell lines (T-24, KK-47) . These results indicate that the amount of GM3 expressed may serve as an i ndicator of the invasion potential of bladder tumor. Furthermore, new antii nvasion therapeutics may be possible by administration of GM3. (C) 2001 Wil ey-Liss, Inc.