Characterization of distinct Gal: 3-O-sulfotransferase activities in human tumor epithelial cell lines and of calf lymph node GlcNAc: 6-O-sulfotransferase activity

We found earlier in human breast and colon tumors, an augmented level of Gal: 3-O-sulfotransferase activities showing, respectively, an acceptor preference to blood group T-hapten (Group A enzymes) or Galβ1,4GlcNAc (Group B enzymes) on the mucin Core 2 structure. The present study reports these enzyme activities in human tumor cell lines and additional tumor specimens. The human colon tumor epithelial cell lines, akin to their parent tumors, express Group B enzyme activity. The acceptor specificity and kinetic properties, such as divalent metal ion activation and pH dependent activity profile, of the colon cancer line LS180 enzyme activity are identical to those of colon tissue specimens. Consistent with breast tumor specimens, the Group A enzyme activity is present in human breast tumor epithelial cell lines, with some exceptions. The Gal: 3-O-sulfotransferases show specific binding to Aleuria aurantia lectin, suggesting the presence of asparagine linked carbohydrate chains containing an inner core α1,6-fucosyl residue on these enzymes. Calf lymph nodes contain GlcNAc: 6-O-sulfotransferase as well as Group A Gal: 3-O-sulfotransferase activities, which differ in pH dependent profiles, pH optima (7.6 and 7.0, respectively) and the influence of Mn²⁺.