Development of beta-lapachone prodrugs for therapy against human cancer cells with elevated NAD(P)H:quinone oxidoreductase 1 levels.
beta-Lapachone, an o-naphthoquinone, induces a novel caspase- and p53-independent apoptotic pathway dependent on NAD(P)H:quinone oxidoreductase 1 (NQO1). NQO1 reduces beta-lapachone to an unstable hydroquinone that rapidly undergoes a two-step oxidation back to the parent compound, perpetuating a futile redox cycle. A deficiency or inhibition of NQO1 rendered cells resistant to beta-lapachone. Thus, beta-lapachone has great potential for the treatment of specific cancers with elevated NQO1 levels (e.g., breast, non-small cell lung, pancreatic, colon, and prostate cancers). We report the development of mono(arylimino) derivatives of beta-lapachone as potential prodrugs. These derivatives are relatively nontoxic and not substrates for NQO1 when initially diluted in water. In solution, however, they undergo hydrolytic conversion to beta-lapachone at rates dependent on the electron-withdrawing strength of their substituent groups and pH of the diluent. NQO1 enzyme assays, UV-visible spectrophotometry, high-performance liquid chromatography-electrospray ionization-mass spectrometry, and nuclear magnetic resonance analyses confirmed and monitored conversion of each derivative to beta-lapachone. Once converted, beta-lapachone derivatives caused NQO1-dependent, mu-calpain-mediated cell death in human cancer cells identical to that caused by beta-lapachone. Interestingly, coadministration of N-acetyl-l-cysteine, prevented derivative-induced cytotoxicity but did not affect beta-lapachone lethality. Nuclear magnetic resonance analyses indicated that prevention of beta-lapachone derivative cytotoxicity was the result of direct modification of these derivatives by N-acetyl-l-cysteine, preventing their conversion to beta-lapachone. The use of beta-lapachone mono(arylimino) prodrug derivatives, or more specifically a derivative converted in a tumor-specific manner (i.e., in the acidic local environment of the tumor tissue), should reduce normal tissue toxicity while eliciting tumor-selective cell killing by NQO1 bioactivation.
Reinicke
Kathryn E
KE
Laboratory of Molecular Stress Responses, Case Western Reserve University, Cleveland, OH 44106, USA.
Bey
Erik A
EA
Bentle
Melissa S
MS
Pink
John J
JJ
Ingalls
Stephen T
ST
Hoppel
Charles L
CL
Misico
Rosana I
RI
Arzac
Gisela M
GM
Burton
Gerardo
G
Bornmann
William G
WG
Sutton
Damon
D
Gao
Jinming
J
Boothman
David A
DA
D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism*; D009285:Naphthoquinones / Q000737:chemistry / Q000494:pharmacology*; D009369:Neoplasms / Q000188:drug therapy / Q000201:enzymology / Q000473:pathology; D011355:Prodrugs / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship
D009285:Naphthoquinones; D011355:Prodrugs; C014638:beta-lapachone; D016660:NAD(P)H Dehydrogenase (Quinone); C447479:NQO1 protein, human