Antiproliferative activity of new 1-aryl-4-amino-1H-pyrazolo[3,4-d]pyrimidine derivatives toward the human epidermoid carcinoma A431 cell line

Synthesis and biol. evaluation of a class of 1-aryl-4-amino-1H-pyrazolo[3,4-d]pyrimidines, e.g., I, are reported. A preliminary cellular assay system using the tumor cell line A431 responding to epidermal growth factor (EGF) for its growth, showed that the compds. were potent inhibitors of cell growth. The inhibition of tumor cell proliferation was not assocd. with blockage of EGF receptor, but substantially due to the interference with the signaling pathway at the level of Src tyrosine kinase and at the level of the downstream effector signal mitogen activated protein kinases, ERK1-2.