Relationship between the content of [14C]glucose-derived monosaccharides in glycoprotein oligosaccharide chains and the state of enterocytic differentiation of HT-29 cells.

The HT-29 cell line derived from a human colon adenocarcinoma has a glucose-dependent state of differentiation which is negatively correlated with the presence of D-glucose in the culture medium. The contribution of glucose to the biosynthesis of N-glycan chains, as a function of the differentiation state of HT-29 cells, was shown by: (a) [14C]glucose incorporation by undifferentiated HT-29 cells being lower after 2 h and higher after 19 h of metabolic labeling than that by differentiated cells; (b) a lack of glucose in the culture medium of undifferentiated HT-29 cells diminishing [14C]glucose incorporation into glycan chains, but not changing the glucose distribution between lipid- and protein-linked saccharides; (c) glucose behavior in undifferentiated HT-29 cells being not related to mannose-glycan metabolism, as the high-mannose compounds labeled with glucose and observed by HPLC showing a different distribution associated with the duration of glucose labeling; and (d) glucose being interconverted into other monosaccharide-glycan constituents in proportions different in differentiated and undifferentiated cell populations.