Differentiation-associated decrease in the proportion of fucosylated polylactosaminoglycans of CaCo-2 human colonic...

Area of Science:

• Cell Biology
• Glycobiology
• Biochemistry

Background:

• CaCo-2 cells, a human colonic adenocarcinoma cell line, spontaneously differentiate into enterocyte-like cells.
• Cellular differentiation involves significant changes in cell surface glycoproteins and their carbohydrate structures.

Purpose of the Study:

• To investigate the alterations in glycoprotein carbohydrate structure during CaCo-2 cell differentiation.
• To correlate changes in specific glycan structures with the acquisition of differentiated enterocyte characteristics.

Main Methods:

• CaCo-2 cells cultured for varying durations (4, 7-9, 19-22 days) were labeled with radioactive fucose or glucosamine.
• Glycopeptides were isolated, digested with Pronase, and fractionated using Bio-Gel P-6 and Datura stramonium agglutinin-agarose affinity chromatography.
• Enzymatic degradation with endo-beta-galactosidase was used to characterize glycan structures.

Main Results:

• A high-molecular-weight glycopeptide fraction, identified as fucosylated polylactosaminoglycans, was present in all culture conditions.
• The proportion of these fucosylated polylactosaminoglycans decreased as cells remained in culture for longer periods.
• Sucrase activity, a marker of enterocyte differentiation, increased with prolonged culture time.

Conclusions:

• Fucosylated polylactosaminoglycans are significantly reduced during the differentiation of CaCo-2 cells into enterocytes.
• The decrease in these glycans is associated with the maturation of CaCo-2 cells and the expression of differentiated functions.