Differential expression of carbohydrate residues in human breast and colon cancer cell lines grown in vitro and in vivo in SCID mice

Background - Tumor progression has been associated with changes in the glycosylation of cancer cells, However, little is known about possible differences in glycosylation of tumour cells grown in vitro and those grown in vivo. Methods - Human breast (n = 4) and colon cancer (n = 4) cell lines were grown in vitro, and in vivo in severe combined immunodeficient (SCID) mice, The carbohydrate profile of the cells was examined using a panel of 17 lectins employing an indirect histochemical technique, Lectin sugar specificities included those for N-acetylgalactosamine (GalNAc), galactose, N-acetylglucosamine, fucose, mannose and bi- and tri-antennary carbohydrate residues. Results - Heterogeneity of carbohydrate expression as indicated by lectin binding pattern was more pronounced, for most cell Lines, in cells grown in SCID mice than for those grown in vitro, The greater heterogeneity of lectin binding results in vivo is in accord with clinical studies which also emphasize the great heterogeneity of carbohydrate expression in tumours. Conclusion - The SCID mouse model is a more realistic representation of carbohydrate expression by cancer cells than cell culture systems.