Antitumoral activity of flavone L-86-8275.

L 86-8275, a flavone of novel structure, was shown to be a kinase inhibitor and to possess surprising potent antiproliferative potency (IC50=0.1-0.15 mu M) on various tumor cell lines after long period of incubation. Short period of incubation was significantly less effective (IC50=133 mu M). In vitro L 86-8275 showed almost no cross-resistance on L 1210 mouse leukemia tumor cell line 110-fold resistant to doxorubicin. In vivo significant antitumoral effects were seen with xenografted lung, colon, mammary and ovarian tumors as well as glioblastoma. T/C values ranged from 29 to 86% and were comparable to standard chemotherapeutic treatment. Optimal schedule required daily oral application of L 86-8275.