摘要:
Ring-substituted bis(phenazine-1-carboxamides), linked by a -(CH2)(3)NMe(CH2)(3)- chain, were prepared from the corresponding substituted phenazine-1-carboxylic acids by reaction of the intermediate imidazolides with bis(3-aminopropyl)methylamine. The compounds were evaluated for growth inhibitory activity in a panel of tumor cell lines, including P388 leukemia, Lewis lung carcinoma, and wild-type (JL(C)) and mutant (JL(A) and JL(D)) forms of human Jurkat leukemia; The latter mutant lines are resistant to topoisomerase (topo) II targeted agents because of lower levels of the enzyme. Analogues with small, lipophilic substituents (e.g,, Me, Cl) at the 9-position were the most potent inhibitors, superior to the corresponding dimeric bis(acridine-4-carboxamides) (bis-DACA analogues). Several of the compounds were preferentially (up to 2-fold) more cytotoxic toward the mutant Jurkat lines than the wild-type. To test whether this selectivity was related to topoisomerase action, the most potent of the compounds (9-methyl) was evaluated in a cell-free system. It poisoned topo I at drug concentrations of 0.25 and 0.5 mu M and inhibited the catalytic activity of both topo I and topo II at concentrations of 1 and 5 mu M, respectively. Results from the NCI human tumor cell line panel showed the compounds had preferential activity toward colon tumor lines ton average 9.5-fold more active in the HT29 line than in the cell line, panel as a whole). Several analogues produced significant growth delays in the relatively refractory subcutaneous colon 38 tumor model in vivo. In particular, the 9-methyl compound was substantially more potent in this tumor model than the clinical dual topo I/II poison DACA (total dose 90 versus 400 mg/kg) with comparable activity. The bis(phenazine-1-carboxamides) are a new and interesting class of dual topo I/II-directed anticancer drugs.