ELEVATED EXPRESSION OF H-TYPE GDP-L-FUCOSE-BETA-D-GALACTOSIDE ALPHA-2-L-FUCOSYL-TRANSFERASE IS ASSOCIATED WITH HUMAN COLON ADENOCARCINOMA PROGRESSION

GDP-L-fucose:beta-D-galactoside alpha-2-L-fucosyltransferase (EC 2.4.1 .69) is a key enzyme in the biosynthesis of fucosylated type 1 and 2 l actoseries structures, such as Lewis b and the H type 2 and Lewis Y, r espectively, that are accumulated in colon adenocarcinoma. Analysis of the mRNA transcript level for the human H gene-encoded beta-D-galacto side alpha-2-L-fucosyltransferase revealed 40- and 340-fold increases in the mRNA levels in all adenocarcinomas and tumor cell lines, respec tively, compared to normal colon mucosa where a low level of mRNA tran script was detected, A. variable increase in mRNA transcript levels wa s observed in 50% of adenomatous polyps, Nucleotide sequence analysis of the protein coding region of the cDNAs derived from normal colon, a denoma, and colon adenocarcinoma revealed 100% homology, suggesting th at there are no tumor-associated allelic variations within the H beta- D-galactoside alpha-2-L-fucosyltransferase cDNA. These results suggest that beta-D-galactoside alpha-2-L-fucosyltransferase expression highl y correlates with malignant progression of colon adenocarcinoma.