Bromodeoxyuridine-induced molecular species conversion of sialic acids of gangliosides and the alteration of cellular phenotypic expression in B16 mouse melanoma cells.
Gangliosides of B16 mouse melanoma cells were characterized and the effects of 5-bromodeoxyuridine (BrdU) on gangliosides were examined in relation to the alteration of cellular phenotypic expression. In melanotic cells, gangliosides were shown to be composed of both hematosides containing N-acetylneuraminic acid (NeuAc-hematoside) and N-glycolylneuraminic acid (NeuGc-hematoside) as determined by thin-layer chromatography, gas chromatography-mass spectrometry and the use of anti-NeuGc-hematoside antiserum. Gangliosides other than hematosides were not detectable under the conditions of thin-layer chromatography employed. BrdU treatment of the melanotic cells induced about a two-fold increase in the ratio of NeuGc-hematosides to the total hematosides without any significant change in the cellular ganglioside content. The treatment concomitantly induced a change in cellular morphology, an increase in cell-to-substrate adhesiveness, and the suppression of tyrosinase activity. Amelanotic cells, which showed cellular phenotypes similar to those of BrdU-treated melanotic cells, were demonstrated to have over twice as much NeuGc-hematosides as compared with the melanotic cells. These results indicate a possible relationship in melanoma cells between the molecular species conversion of sialic acids of hematosides and the alteration of cellular phenotypic expression by BrdU treatment or spontaneous amelanization.
D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology*; D002448:Cell Adhesion; D002478:Cells, Cultured; D005732:Gangliosides / Q000378:metabolism*; D008545:Melanoma / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D014442:Monophenol Monooxygenase / Q000378:metabolism; D009363:Neoplasm Proteins / Q000378:metabolism; D009374:Neoplasms, Experimental / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D012794:Sialic Acids / Q000378:metabolism*
D005732:Gangliosides; D009363:Neoplasm Proteins; D012794:Sialic Acids; D014442:Monophenol Monooxygenase; D001973:Bromodeoxyuridine