Expression of Forssman glycolipid and blood group-related antigens A, Le(x), and Le(y) in human gastric cancer and in fetal tissues.

The expression of Forssman glycolipid antigen in human gastric cancers was investigated by thin-layer chromatogram immunostaining of glycolipid fractions. Incompatible blood group A antigen, Le(x) and Le(y) antigen were also studied in comparison with Forssman antigen. Forssman glycolipid as the pentaglycosylceramide was demonstrated in nine out of 12 gastric cancers, and in three out of 10 adjacent uninvolved tissues. In most cases the content of Forssman glycolipid was increased in the cancers compared with that in the uninvolved counterparts. Forssman pentaglycosylceramide was also detected in some normal gastric mucosae (two out of four), and in a fetal gastrointestinal tract tissue. In immunohistochemical examination of gastric cancer tissues, sialidase treatment revealed a positive staining with anti-Forssman antibody. Some cancer tissues from patients with blood group O were found to contain blood group A-active glycolipids, which could be distinguished from Forssman glycolipid by thin-layer chromatogram immunostaining. The incidence of incompatible A-active glycolipids was two out of 10 cancers from patients with blood group O or B. Le(x)- and Le(y)-active glycolipids were detected in most of the preparations and were not accumulated consistently in the cancers.