Biochemical characteristics, metabolism, and antitumor activity of several acetylated hexosamines

Abstract

We have synthesized several potential inhibitors and/or modifiers of the carbohydrate portion of plasma membrane glycoconjugates. These include fluorinated and actylated analogs of D-glucosamine, D-galactosamine, and D-mannosamine. These compounds have been tested to determine their effects on both[14C] glucosamine and [3H] leucine incorporation into glycoconjugate and on cell growth and viability using P-288 murine lymphoma cells maintained in tissue culture. The most cytotoxic agent tested was 2-acetamido-2-deoxy-1,3,4,6-tetra-O-acetyl-beta-D-glucopyranose or simply beta-pentaacetylglucosamine which prevented cell growth at 10(-4)-10(-3) M. beta-Pentaacetylglucosamine cytotoxicity was correlated with its high lipid solubility, having an octanol/water partition coefficient of 0.424 as compared with 0.278 for the alpha-anomer and 0.017 for N-acetylglucosamine. In vitro metabolism studies with [4C]- and/or [3H]-labeled pentaacetylglucosamine have indicated intracellular de-O-acetylation leading to the biosynthesis of UDP-N-acetylglucosamine, followed by the incorporation of this sugar into cellular glycoprotein. Concomitant with the formation of increased amounts of this nucleotide sugar, intracellular UTP and CTP pools fell to one third normal within 3 h after the administration of 1 mM pentaacetylglucosamine. At present it is unclear whether the cytotoxicity of beta-pentaacetylglucosamine or other similar agents is due to alterations in nucleotide and nucleotide-sugar pools causing a decrease in energy charge and polynucleotide biosynthesis or is due to a direct effect on membrane glycoconjugate biosynthesis.

Glycosylation-dependent inhibition of cutaneous lymphocyte–associated antigen expression: implications in modulating lymphocyte migration to skin

“…Easy Tag [ 35 S]-protein labeling mix was purchased from NEN Life Science products (Boston, MA). The 2-acetamido-1,3,6-tri-O-acetyl-4-deoxy-4-fluoro-Dglucopyranose (4-F-GlcNAc), which possesses a fluorine substitution at carbon-4 of the pyranose ring ( Figure 1A) and putatively blocks poly-Nacetyllactosamine elongation [31][32][33][34] ( Figure 1B-C …”

“…With the aim of modulating CLA expression, we investigated the relative potency of metabolic inhibitors of glycosylation with O-glycan, N-glycan, or poly-N-acetyllactosaminyl glycan inhibitory specificities to diminish CLA expression and function as natively expressed on human skin-homing T lymphocytes. The well-characterized O-glycan inhibitor benzyl-O-N-acetylgalactosamide (BAG), the N-glycan inhibitors tunicamycin and swainsonine, and the newly described putative inhibitor of poly-Nacetyllactosamine synthesis, 2-acetamido-1,3,6-tri-O-acetyl-4-deoxy-4-fluoro-D-glucopyranose (4-F-GlcNAc), [31][32][33][34] were used to metabolically modify oligosaccharide structures. Since there is little direct evidence on the mechanism of the anticarbohydrate action of 4-F-GlcNAc, we performed lectin blotting experiments and metabolic studies with radiolabeled 4-F-GlcNAc to analyze the relevant glycan modifications.…”

The biochemical and ultrastructural effects of tunicamycin and D‐glucosamine in L1210 leukemic cells

“…Following treatment cells were washed thoroughly and 1 x lo7 cells from each group were extracted with perchloric acid (PCA) (6% in 1 M ammonium formate, pH 4.4) for 10 min at 4". The acid-soluble extracts were neutralized with 0.1 N KOH, centrifuged at 1200g, and aliquots of the supernatants were chromatographed by high-pressure chromatography (HPLC) as described previously (Bernacki et al, 1977). UDP-D-[6-3Hl-N-acetylglucosamine was used as an authentic standard for determining nucleotide retention time while the retention times of the other peaks were compared with those of authentic nucleotide standards.…”

Regulation of Heparan Sulfate and Chondroitin Sulfate Glycosaminoglycan Biosynthesis by 4-Fluoro-glucosamine in Murine Airway Smooth Muscle Cells

“…4-F-GlcNAc used for cell culture experiments has O-acetyl groups at several of its ring positions, which in effect increases its cell permeability compared with that of unmodified forms (6). After hydrolysis to remove the O-acetyl residues, 4-F-GlcNAc, like GlcNAc, must be converted to UDP-4-F-GlcNAc, which in turn can be a substrate (or inhibitor) of enzyme reactions that use UDP-GlcNAc.…”