title: D-glucosamine-induced changes in nucleotide metabolism and growth of colon-carcinoma cells in culture.
abstract: Human colon-carcinoma cells were exposed to D-glucosamine at 2.5, 5 and 10 mM, concentrations that were growth-inhibitory but not cytocidal in the presence of a physiological glucose concentration. Labelling of these HT-29 cells with D-[14C]-glucosamine, followed by nucleotide analyses, demonstrated that UDP-N-acetyl-hexosamines represented the major intracellular nucleotide pool and the predominant metabolite of the amino sugar. D-[14C]Glucosamine was not a precursor of UDP-glucosamine. After 4h exposure to D-glucosamine (2.5 mM), the pool of UDP-N-acetylhexosamines was increased more than 6-fold, whereas UTP and CTP were markedly decreased. UDP-glucuronate content increased by more than 2-fold, whereas purine nucleotide content was little altered. Uridine (0.1 mM) largely reversed the decrease in UTP, CTP, UDP-glucose and UDP-galactose, while intensifying the expansion of the UDP-N-acetylhexosamine pool. Uridine did not reverse the D-glucosamine-induced retardation of growth in culture. A 50% decrease in growth also persisted when uridine and cytidine, cytidine alone, or UDP, were added together with D-glucosamine. The growth-inhibitory effect of the amino sugar could therefore be best correlated with the quantitative change in the pattern of sugar nucleotides, and, in particular, with the many-fold increase in UDP-N-acetylglucosamine and UDP-N-acetylgalactosamine.
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology; D003562:Cytidine / Q000494:pharmacology; D005944:Glucosamine / Q000494:pharmacology*; D006801:Humans; D009711:Nucleotides / Q000378:metabolism*; D011741:Pyrimidine Nucleosides / Q000494:pharmacology; D014529:Uridine / Q000494:pharmacology; D014530:Uridine Diphosphate / Q000494:pharmacology
chemical_list: D009711:Nucleotides; D011741:Pyrimidine Nucleosides; D014530:Uridine Diphosphate; D003562:Cytidine; D005944:Glucosamine; D014529:Uridine