Novel<i>N</i><sup>2</sup>-Substituted Pyrazolo[3,4-<i>d</i>]pyrimidine Adenosine A<sub>3</sub>Receptor Antagonists: Inhibition of A<sub>3</sub>-Mediated Human Glioblastoma Cell Proliferation<sup>†</sup>
作者:Sabrina Taliani、Concettina La Motta、Laura Mugnaini、Francesca Simorini、Silvia Salerno、Anna Maria Marini、Federico Da Settimo、Sandro Cosconati、Barbara Cosimelli、Giovanni Greco、Vittorio Limongelli、Luciana Marinelli、Ettore Novellino、Osele Ciampi、Simona Daniele、Maria Letizia Trincavelli、Claudia Martini
DOI:10.1021/jm901785w
日期:2010.5.27
Adenosine induces glioma cell proliferation by means of an antiapoptotic effect, which is blocked by cotreatment with selective A(3) AR antagonists. In this study, a novel series of N-2-substituted pyrazolo[3,4-d]pyrimidines 2a-u was developed as highly potent and selective A(3) AR antagonists. The most performing compounds were derivatives 2a (R-1 = CH3 and R-2 = COC6H5; K-i 334, 728, and 0.60 nM at the human A(1), A(2A), and A(3) ARs, respectively) and 2b (R-1 = CH3 and R-2 = COC6H4-4-OCH3; K-i 1037, 3179, and 0.18 nM at the human A(1), A(2A), and A(3) ARs, respectively), which counteracted the effect of the A(3) AR agonists Cl-IB-MECA and IB-MECA on human glioma U87MG cell proliferation. This effect was concentration-dependent, with IC50 values comparable to A(3) AR binding affinity values of 2a and 2b, thereby suggesting that their effects were receptor-mediated. Furthermore, the antiproliferative activity of the new compounds was demonstrated to be mediated by the block of A(3) AR agonist activation of intracellular kinases ERK 1/2.