Adenosine 5’-methylenediphosphate is an inhibitor of ecto-5’-nucleotidase, also known as CD73, with a Kivalue of 37 nM.1It inhibits cAMP accumulation induced by adenosine 5’-monophosphate , adenosine 5’-diphosphate , or adenosine 5’-triphosphate but not adenosine in VA-13 human fibroblasts when used at a concentration of 100 μM. Adenosine 5’-methylenediphosphate reduces proliferation of U138MG glioma cells, as well as inhibits the invasion and migration of MHCC97H hepatocellular carcinoma (HCC) cells in a migration assay.2,3It increases tumor infiltration of CD3+CD8+T cells and reduces tumor growth in a K1735 murine melanoma model when administered at a dose of 400 μg mouse.4 1.Bruns, R.F.Adenosine receptor activation by adenine nucleotides requires conversion of the nucleotides to adenosineNaunyn Schmiedebergs Arch. Pharmacol.315(1)5-13(1980) 2.Braganhol, E., Tamajusuku, A.S.K., Bernardi, A., et al.Ecto-5′-nucleotidase CD73 inhibition by quercetin in the human U138MG glioma cell lineBiochim. Biophys. Acta1770(9)1352-1359(2007) 3.Shali, S., Yu, J., Zhang, X., et al.Ecto 5′ nucleotidase (CD73) is a potential target of hepatocellular carcinomaJ. Cell Physiol.234(7)10248-10259(2018) 4.Forte, G., Sorrentino, R., Montinaro, A., et al.Inhibition of CD73 improves B cell-mediated anti-tumor immunity in a mouse model of melanomaJ. Immunol.189(5)2226-2233(2021)
Nicotinamide-d4 is intended for use as an internal standard for the quantification of nicotinamide by GC- or LC-MS. Nicotinamide is an amide form of niacin, which is also known as vitamin B3, that can be biosynthesized in vivo or obtained through the diet. It is a precursor in the synthesis of the metabolic cofactor NAD+ and an inhibitor of sirtuin 1 (SIRT1; IC50 = <50 µM). Nicotinamide (10 µM) increases the activity of serine palmitoyltransferase (SPT) and the biosynthesis of ceramide, glucosylceramide, sphingomyelin, free fatty acids, and cholesterol in primary human keratinocytes. Nicotinamide (40 µM) induces apoptosis in SNU-398, SNU-739, and HepG2 hepatocellular carcinoma (HCC) cells, and it prevents the formation of neoplastic lesions in a diethylnitrosamine-induced mouse model of HCC. Unlike niacin, nicotinamide does not reduce plasma lipid levels or induce flushing.