title: Adenosine modulates cell growth in human epidermoid carcinoma (A431) cells.
abstract: Adenosine mediates many physiological functions via activation of extracellular receptors. The modulation of cell growth by adenosine was found to be receptor-mediated. In A431 cells adenosine evoked a biphasic response in which a low concentration (approximately 10 microM) produced inhibition of colony formation but at higher concentrations (up to 100 microM) this inhibition was progressively reversed. Evidence for the involvement of A1 (inhibitory) and A2 (stimulatory) adenosine receptors in regulating cell growth of these tumor cells was obtained through plating efficiency studies based on the relative potency of adenosine agonists and antagonists. When both A1 and A2 receptors were blocked, colony formation or growth was not inhibited at low concentrations of adenosine but was inhibited at high adenosine concentrations.
authors.affiliation: Department of Biochemistry, National University of Singapore, Kent Ridge.
authors.forename: H B
authors.initials: HB
authors.lastname: Tey
authors.forename: H E
authors.initials: HE
authors.lastname: Khoo
authors.forename: C H
authors.initials: CH
authors.lastname: Tan
mesh_terms: D000241:Adenosine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002455:Cell Division / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D011983:Receptors, Purinergic / Q000502:physiology*; D013806:Theophylline / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014970:Xanthines / Q000494:pharmacology
chemical_list: D011983:Receptors, Purinergic; D014970:Xanthines; C051360:1,3-dipropyl-8-cyclopentylxanthine; D013806:Theophylline; D000241:Adenosine