EXPRESSION OF ALPHA-1-6 FUCOSYL-TRANSFERASE IN RAT-TISSUES AND HUMAN CANCER CELL-LINES

GDP-L-Fuc:N-acetyl-beta-D-glucosaminide alpha 1-6 fucosyltransferase ( alpha 1-6FucT) catalyzes the transfer of a fucosyl residue from GDP-fu cose to the asparagine-linked GlcNAc residue of complex N-glycans via alpha 1-6 linkage. These oligosaccharide structures are essential for the attachment of polysialic acid to the neural-cell-adhesion molecule , and its levels are useful for the differential diagnosis of hepatoce llular carcinomas with respect to the microheterogeneity of alpha-feto protein. We have been successful in the purification and cDNA cloning of alpha 1-6FucT from porcine brain and from a human gastric-cancer ce ll line. In the present study, mRNA expression of alpha 1-6FucT in var ious rat tissues and human cancer cell lines was examined, along with the expression of alpha 1-6FucT mRNA and the induction by treatment wi th several cytokines. Northern-blot analysis indicated high expression levels of alpha 1-6FucT in brain and gastrointestinal-tract tissues o f normal rats, as well as for a number of lung-cancer, gastric-cancer and colon-cancer cell lines. Although various cytokines did not induce alpha 1-6FucT mRNA, differentiation of a tumor cell enhanced the mRNA by 2- to 3-fold. These results may provide new insight into studies o n alpha 1-6FucT in terms of carcinogenesis or differentiation. (C) 199 7 Wiley-Liss, Inc.