To identify
glycolipid antigens associated with histologically defined types of ovarian
carcinomas, we determined the amounts of α2,6-sialyl and Lewis-active
glycolipids, the specific activities of the α2,3- and α2,6-sialyltransferases, and the gene expression of
sugar transferases in mucinous and
serous cystadenocarcinoma,
clear cell adenocarcinoma and
endometrioid carcinoma tissues and cell lines derived from them. α2,6-sialyl
glycolipid IV(6)NeuAcα-nLc(4)Cer detected with a newly developed
monoclonal antibody, Y916, was present in 5/7
serous cystadenocarcinoma cases in relatively higher amounts than those in the other
carcinoma tissues. On the other hand, the amounts of Lewis-active
glycolipids in
serous cystadenocarcinoma tissues were lower than those in the other
carcinoma tissues. No correlation was observed between the structures of Lewis
glycolipids and the histological classification. The gene expression of α2,3- and α2,6-sialyltransferases and α1,3/4-
fucosyltransferase for the synthesis of Lewis-active
glycolipids was not positively correlated with the amounts of the respective
glycolipids, probably due to the epigenetic regulation of
transferases in the overall metabolic pathways for lacto-series
glycolipids. However, the amounts of GM3 and GD3 with short
carbohydrate chains correlated with the relative intensities of GM3 and GD3 synthase gene expression, respectively. Among ovarian
carcinoma-derived cell lines, the
serous cystadenocarcinoma-derived ones exhibited a lower frequency of Lewis-active
glycolipid expression than the other
carcinoma-derived ones, which was similar to that in the respective tissues. Thus,
malignancy-related Lewis-active
glycolipids were shown to be regulated in different modes in ovarian
serous cystadenocarcinomas and the other
carcinomas.