Self-Immolative Nitrogen Mustards Prodrugs Cleavable by Carboxypeptidase G2 (CPG2) Showing Large Cytotoxicity Differentials in GDEPT
作者:Dan Niculescu-Duvaz、Ion Niculescu-Duvaz、Frank Friedlos、Jan Martin、Panos Lehouritis、Richard Marais、Caroline J. Springer
DOI:10.1021/jm020462i
日期:2003.4.1
Nineteen novel potential self-immolative prodrugs and their corresponding drugs have been synthesized for gene-directed enzyme prodrug therapy (GDEPT) with carboxypeptidase G2 (CPG2) as the activating enzyme. The compounds are derived from o- and p-amino and p-methylamino aniline nitrogen mustards. Their aqueous stability, kinetics of drug release by CPG2, and cytotoxicity in the colon carcinoma cell line WiDr, expressing either surface-tethered CPG2 (stCPG2(Q)3) or control beta-galactosidase, are assessed. The effect of various structural features on stability, kinetics of activation, and biological activity is discussed. The p-methylamino prodrugs are the most stable compounds from this series, with the largest cytotoxicity differentials between CPG2-expressing and nonexpressing cells. The most potent compounds in all series are prodrugs of bis-iodo nitrogen mustards. 4-N-[4'-Bis(2"-iodoethyl)aminophenyll-N'-methylcarbamoyloxymethyl}phenylcarbamoyl-L-glutamic acid, compound 39b, is 124-fold more cytotoxic to WiDr cells expressing CPG2 than to cells expressing beta-galactosidase. An additional six compounds show better cytotoxicity differential than the published N-4-[(2-chloroethyl)(2-mesyloxyethyl)amino]benzoyl}-L-glutamic acid (CMDA) prodrug.