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)
Peptide YY (PYY) is a 36-amino acid peptide and anorectic gut hormone agonist for the neuropeptide Y receptors Y1, Y2, Y5, and Y6 with EC50 values of 0.7, 0.58, 1, and 0.8 nM, respectively, for supression of forskolin-induced cAMP accumulation. PYY is cleaved in vivo to PYY (3-36) . Release of PYY occurs postprandially in proportion to calorie intake from intestinal enteroendocrine L cells, indicating it may be a satiety signal. In humans, PYY inhibits food intake and gastrointestinal transit in both lean and obese subjects.
Pituitary adenylate cyclase-activating peptide (PACAP) (6-27) is a PACAP receptor antagonist with IC50 values of 1,500, 600, and 300 nM, respectively, for rat PAC1, rat VPAC1, and human VPAC2 recombinant receptors expressed in CHO cells. It binds to PACAP receptors on SH-SY5Y and SK-N-MC human neuroblastoma and T47D human breast cancer cells (IC50s = 24.5, 106, and 105 nM, respectively) and inhibits cAMP accumulation induced by PACAP (1-38) (Kis = 457, 102, and 283 nM, respectively, in SH-SY5Y, SK-N-MC, and T47D cells). In vivo, in newborn pigs, PACAP (6-27) (10 μM) inhibits vasodilation of pial arterioles induced by PACAP (1-27) and PACAP (1-38) . It also inhibits PACAP (1-27)-stimulated increases in plasma insulin and glucagon levels and pancreatic venous blood flow in dogs when administered locally to the pancreas at a dose of 500 μg.
Tyr-α-CGRP is an N-terminal extended tyrosinated analogue of α-calcitonin gene-related peptide . It binds to amylin receptors AMY1 and AMY3 in COS-7 cells expressing the human receptors (IC50s = 141 and 1.86 nM, respectively). Tyr-α-CGRP also binds to and stimulates cAMP accumulation in rat L6 myocytes (IC50 = 4 nM; EC50 = 12 nM). It also binds to rat brain and spleen membrane preparations (IC50s = 0.2 and 0.5 nM, respectively), induces positive chronotropic and inotropic effects in isolated right and left guinea pig atria (EC50s = 282 and 74 nM, respectively), and inhibits the twitch response in rat vas deferens (EC50 = 1.9 nM).