| Abstract: |
Retinoids have been shown to inhibit the growth and modulate the glycosylation of head and neck squamous cell carcinoma (HNSCC) cells including the MDA886Ln cells. To examine the effects of β-all-trans retinoic acid (RA) on glycoconjugates in HNSCC MDA886Ln cells, the cells were grown in the absence or presence of 1μM RA and then labeled with tritiated monosaccharides, extracted and analysed by polyacrylamide gel electrophoresis and fluorography. RA increased markedly the incorporation of [3H]-glucosamine, [3H]-galactose, and [3H]-mannose into numerous cellular glycoconjugates, however, the incorporation of [3H]-fucose and [3H]-leucine was almost unaffected by RA. RA increased the incorporation of glucosamine and galactose but not mannose into high molecular weight (HMW) glycoconjugates of about 220 and 500-600 kDa. To analyse the steady state level of glycoconjugates by lectin blotting, extracts of unlabeled cells were separated by gel electrophoresis and the gels were probed with 125I-labeled wheat germ agglutinin (WGA) and Maackia amurensis (MA) agglutinin. Both lectins were found to bind to numerous glycoconjugates including the HMW gIycoconjugates, whereas 125I-peanut agglutinin bound only to the HMW glycoconjugates. RA treatment increased the binding of all three Iectins to the HMW glycoconjugates. These findings demonstrate that RA enhanced the incorporation of specific monosaccharides into a variety of glycoconjugates and in particular into HMW mucin-like glycoconjugates. This effect of RA may be the result of induction of a more normal differentiation state of the HNSCC cells. |
| Keywords: |
controlled study; human cell; squamous cell carcinoma; carcinoma, squamous cell; conference paper; cell division; cell differentiation; tumor cells, cultured; cell culture; immunocytochemistry; head and neck cancer; head and neck neoplasms; tumor cell; glycosylation; microscopy, fluorescence; leucine; molecular weight; retinoic acid; carbohydrate analysis; electrophoresis, polyacrylamide gel; gel electrophoresis; retinoids; tretinoin; galactose; lectins; glucosamine; glycoconjugates; mannose; triticum aestivum; humans; human; priority journal; agglutinins; mda886ln; microscopy, phase-contrast; arachis hypogaea; maackia amurensis
|
