NGF and neoplasm: The effect of A2A or A3AR stimulation on NF-kB p65 subunit activation was investigated in untreated or NGF-treated PC12 cells and U87MG cells respect to rat cortical neurons revealing the capability of the A2A (CGS 21680) or A3AR (Cl-IB-MECA) agonists to significantly decrease the activation of NF-kB in the tumor cells after 24 hours of treatment (Fig. 3).