Sacks P G, Amos B, Lotan R
Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
Glycoconj J. 1996 Oct;13(5):791-6. doi: 10.1007/BF00702343.
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 beta-all-trans retinoic acid (RA) on glycoconjugates in HNSCC MDA886Ln cells, the cells were grown in the absence or presence of 1 microM 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 incorportion 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 glycoconjugates, whereas 125I-peanut agglutinin bound only to the HMW glycoconjugates RA treatment increased the binding of all three lectins 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.
维甲酸已被证明能抑制头颈部鳞状细胞癌（HNSCC）细胞包括MDA886Ln细胞的生长并调节其糖基化。为了研究β - 全反式维甲酸（RA）对HNSCC MDA886Ln细胞中糖缀合物的影响，将细胞在不存在或存在1微摩尔RA的情况下培养，然后用氚标记的单糖进行标记，提取并通过聚丙烯酰胺凝胶电泳和荧光自显影进行分析。RA显著增加了[3H] - 葡萄糖胺、[3H] - 半乳糖和[3H] - 甘露糖掺入多种细胞糖缀合物中，然而，[3H] - 岩藻糖和[3H] - 亮氨酸的掺入几乎不受RA影响。RA增加了葡萄糖胺和半乳糖但不是甘露糖掺入约220 kDa以及500 - 600 kDa的高分子量（HMW）糖缀合物中。为了通过凝集素印迹分析糖缀合物的稳态水平，将未标记细胞的提取物进行凝胶电泳分离，并用125I标记的麦胚凝集素（WGA）和山嵛菜凝集素（MA）进行探针检测。发现这两种凝集素都能与包括HMW糖缀合物在内的多种糖缀合物结合，而125I - 花生凝集素仅与HMW糖缀合物结合。RA处理增加了所有三种凝集素与HMW糖缀合物的结合。这些发现表明，RA增强了特定单糖掺入多种糖缀合物中，特别是掺入HMW粘蛋白样糖缀合物中。RA的这种作用可能是诱导HNSCC细胞进入更正常分化状态的结果。
