The identification of a neutral glycosphingolipid antigenic marker for metastatic cells in the R3230AC rat mammary adenocarcinoma.

The process of metastasis is a complex process involving numerous steps, and it is thought that cells able to complete all of these steps and form metastatic foci form a unique subpopulation of cells within the tumor. To study this metastatic subpopulation, a marker for the metastatic cells is required. We have previously described the enrichment of soybean agglutinin binding cells in tumor populations enriched for lymphatic metastasis [1]. In this study we provide evidence that the cell-surface structure binding soybean agglutinin is a neutral glycosphingolipid. Using monoclonal antibodies generated against this glycolipid, highly metastatic tumor populations were depleted of cells containing this glycolipid. These depleted cell populations were found to be equally tumorigenic to that of the untreated population but were much less metastatic. These results suggest that this glycolipid may be a useful marker for metastatic cells.