Loss of epithelial cell surface carbohydrates during experimental oral carcinogenesis in the rat.
Cell surface glycoconjugates were investigated in a rat model of oral chemical carcinogenesis. The lectins Griffonia simplicifolia (GS-I-B4; specific for alpha-D-galactosyl end groups) and Ulex europeus (UEA-I; specific for alpha-L-fucosyl groups) were examined microspectrofluorimetrically in the oral epithelium of rats painted with the carcinogen 4-nitroquinoline N-oxide (4NQO) and compared with those treated with solvent alone. After labelling with GS-I-B4, the fluorescent intensity of the basal and parabasal epithelial cells was significantly less after 9 months of 4NQO treatment and in overt squamous cell carcinomas compared to controls. The fluorescent activity of the spinous epithelial cells in the non-invasive tissues treated with 4NQO and in the well differentiated (sites of keratin elaboration) malignant epithelium of squamous cell carcinomas was unchanged after labelling with UEA-I. UEA-I failed to stain undifferentiated (areas lacking keratin) malignant epithelium. The findings indicate that alpha-D-galactosyl residues are diminished on the membranes of premalignant and malignant rat epithelial cells. The expression of alpha-L-fucosyl groups, however, remains unchanged in premalignant rat oral epithelium and is closely correlated to the presence of keratin in the malignant epithelium of squamous cell carcinomas.
D015112:4-Nitroquinoline-1-oxide; D000818:Animals; D050260:Carbohydrate Metabolism; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002471:Cell Transformation, Neoplastic / Q000378:metabolism*; D037102:Lectins; D008297:Male; D009062:Mouth Neoplasms / Q000139:chemically induced / Q000378:metabolism*; D037121:Plant Lectins; D051381:Rats; D011919:Rats, Inbred Strains
D037102:Lectins; D037121:Plant Lectins; C036850:Ulex europaeus lectins; D015112:4-Nitroquinoline-1-oxide