HCT116 cells as experimental model to study nuclear fucosylation

ANGELONI G; IRAZOQUI FJ

Mendoza, Argentina

Congreso; SAIB; 2022

Glycosylation has been found to be involved in tumor malignancy, developmentalprocesses, and immune system, which has led to new insights into many human diseases.In cases of colon cancer, many reports have suggested that changes in glycosylation areinvolved in carcinogenesis and metastasis. Particularly, aberrant glycosylation is associatedwith the acquisition of all characteristic features of tumor cells. Fucosylation represents thetransfer of a fucose residue (from GDP-fucose) to oligosaccharide chains. Most GDP-fucoseis synthesized by the de novo pathway, in which GDP-mannose is transformed intoGDP-fucose through three steps catalyzed by GDP-mannose-4,6-dehydratase (GMDS), andFX, an epimerase-reductase enzyme. The salvage pathway synthesizes GDP-fucose fromfree fucose derived from extracellular or lysosomal sources. The deficiency of GMDS hasbeen reported for HCT116 cell line, caused by a deletion of 400 bp, which corresponds tothree exons encoding functionally critical domains for enzyme activity. In the present work,we evaluate HCT116 cells as an in vivo model for the study of nuclear fucosylation. SinceGDP-fucose is deficient in HCT116 cells, this cell line shows a marked decrease in thefucosylation level, which we characterize by western-blot and microscopy analysis. Inaddition, we were able to recover the fucosylation phenotype by taking advantage of thesalvage pathway, supplementing the culture medium of the cell line with free fucose. Thiscaused an increase in the fucosylation levels not only in the whole cell but also in purifiednuclei. These results place the HCT116 cell line as a good model for fucosylation studies atthe cellular and nuclear level, where we are able to “turn on and off” the fucosylationpathway as needed just by supplementing with free fucose.