CONVERSION OF SHORT-CHAIN CERAMIDES TO SHORT-CHAIN CERAMIDE GM3 IN B16 MELANOMA-CELLS

We report that short-chain ceramide (Cer), C-2- and C-6-Cer, were immediately glycosylated and finally converted to short-chain Cer GM3 in B16 melanoma cells, By addition of either C-2- or C-6-Cer to a cell culture of B16 melanoma in the presence of [C-14]Gal, the radiolabeled precursor, was incorporated into each of two novel glycosphingolipids (GSLs) within 30 min along with synthesis of normal GSLs, These novel GSLs were identified as C-2-, C-6-Cer cerebrosides and C-2-, C-6-Cer GM3, respectively, In comparison with C-2-Cer, C-6-Cer was found to be much more efficiently converted to the GSLs, whereas no glycosylated sphingosine was detectable when it was added in place of short-chain Cer.