Relationship between NAD(P)H:quinone oxidoreductase 1 (NQO1) levels in a series of stably transfected cell lines and susceptibility to antitumor quinones.
AffiliationDepartment of Pharmaceutical Sciences, School of Pharmacy and Cancer Center, Campus Box C238, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
MetadataShow full item record
AbstractTo investigate the importance of NAD(P)H:quinone oxidoreductase 1 (or DT-diaphorase; NQO1) in the bioactivation of antitumor quinones, we established a series of stably transfected cell lines derived from BE human colon adenocarcinoma cells. BE cells have no NQO1 activity due to a genetic polymorphism. The new cell lines, BE-NQ, stably express wild-type NQO1. BE-NQ7 cells expressed the highest level of NQO1 and were more susceptible [determined by the thiazolyl blue (MTT) assay] to known antitumor quinones and newer clinical candidates. Inhibition of NQO1 by pretreatment with an irreversible inhibitor, ES936 [5-methoxy-1,2-dimethyl-3-[(4-nitrophenoxy)methyl]indole-4,7-dione], protected BE-NQ7 cells from toxicity induced by streptonigrin, ES921 [5-(aziridin-1-yl)-3-(hydroxymethyl)-1,2-dimethylindole-4,7-dione], and RH1 [2,5-diaziridinyl-3-(hydroxymethyl)-6-methyl-1,4-benzoquinone]. RH1 was evaluated further by clonogenic assay for cytotoxic response and was more cytotoxic to BE-NQ7 cells than to BE cells. Cytotoxicity was abrogated by inhibition of NQO1 with ES936 pretreatment. Using a comet assay to evaluate DNA cross-linking, BE-NQ7 cells demonstrated significantly higher DNA cross-links than did BE cells in response to RH1 treatment. DNA cross-linking in BE-NQ7 cells was observed at very low concentrations of RH1 (5 nM), confirming that NQO1 activates RH1 to a potent cross-linking species. Further studies using streptonigrin, ES921, and RH1 were undertaken to analyze the relationship between NQO1 activity and quinone toxicity. Toxicity of these compounds was measured in a panel of BE-NQ cells expressing a range of NQO1 activity (23-433 nmol/min/mg). Data obtained suggest a threshold for NQO1-induced toxicity above 23 nmol/min/mg and a sharp dose-response curve between the no effect level of NQO1 (23 nmol/min/mg) and the maximal effect level (>77 nmol/min/mg). These data provide evidence that NQO1 can bioactivate antitumor quinones in this system and suggest that a threshold level of NQO1 activity is required to initiate toxic events.
CitationRelationship between NAD(P)H:quinone oxidoreductase 1 (NQO1) levels in a series of stably transfected cell lines and susceptibility to antitumor quinones. 2001, 61 (12):1509-16 Biochem. Pharmacol.
- A new screening system for NAD(P)H:quinone oxidoreductase (NQO1)-directed antitumor quinones: identification of a new aziridinylbenzoquinone, RH1, as a NQO1-directed antitumor agent.
- Authors: Winski SL, Hargreaves RH, Butler J, Ross D
- Issue date: 1998 Dec
- Development of a new isogenic cell-xenograft system for evaluation of NAD(P)H:quinone oxidoreductase-directed antitumor quinones: evaluation of the activity of RH1.
- Authors: Dehn DL, Winski SL, Ross D
- Issue date: 2004 May 1
- Dissecting the role of multiple reductases in bioactivation and cytotoxicity of the antitumor agent 2,5-diaziridinyl-3-(hydroxymethyl)-6-methyl-1,4-benzoquinone (RH1).
- Authors: Yan C, Kepa JK, Siegel D, Stratford IJ, Ross D
- Issue date: 2008 Dec
- Expression of human NAD(P)H: quinone oxidoreductase (DT-diaphorase) in Chinese hamster ovary cells: effect on the toxicity of antitumor quinones.
- Authors: Gustafson DL, Beall HD, Bolton EM, Ross D, Waldren CA
- Issue date: 1996 Oct
- RH1 induces cellular damage in an NAD(P)H:quinone oxidoreductase 1-dependent manner: relationship between DNA cross-linking, cell cycle perturbations, and apoptosis.
- Authors: Dehn DL, Inayat-Hussain SH, Ross D
- Issue date: 2005 May