Expression of Globo‐series Gangliosides in Human Renal Cell Carcinoma

Gangliosides have been shown to be involved in development, differentiation, oncogenesis, and cancer progression. We investigated immunohistochemical expression of globo‐series gangliosides in human renal cell carcinoma (RCC) and whether their expression is related to the clinical course. The expression of globo‐series gangliosides was evaluated in fresh‐frozen sections of 55 primary renal tumors and 8 metastatic deposits using monoclonal antibodies RM1 and RM2, which define mono‐sialosyl and disialosyl galactosylgloboside, respectively. The immunorcaetivity of primary tumors to RM1 and/or RM2 was correlated with the clinicopathological data. Cumulative incidence of metastasis detected at initial diagnosis and during the follow‐up period was significantly higher in the cases whose primary tumors were RMl/RM2‐positive (RM1 and/or RM2‐positive) than in the RM1/ RM2‐negative (neither RM1 nor RM2‐positive) cases (P<0.05). During the follow‐up period, metastasis developed in none of the RMl/RM2‐negative cases which had not shown metastasis at initial diagnosis. High nuclear grade was observed only in the RMl/RM2‐positive cases. The RM1/RM2‐positive rate of the metastatic deposits was higher than that of the primary tumors. Furthermore, a metastatic deposit obtained from one of the cases whose primary tumors were equivocal for RM1/ RM2 was extensively stained by RM1 and RM2. These results indicate that globo‐series gangliosides may be one of the biochemical indicators related to the metastatic potential of human RCC.