Hydroquinone resistance in a murine myeloblastic leukemia cell line. Involvement of quinone reductase and glutathione-dependent detoxification in nonclassical multidrug resistance.
A hydroquinone-resistant derivative of the M1 cell line, designated M1HQ, was generated and used to evaluate the biochemical mechanism responsible for resistance to oxidative stress-inducing agents. The hydroquinone concentrations that were cytotoxic to 50 and 90% of the parental M1 cell line in 48 hr were 25 and 90 microM, respectively, whereas exposure to 500 microM hydroquinone did not decrease M1HQ viability significantly. M1HQ cells grew slower than M1 cells and exhibited significantly higher resistance to colchicine, doxorubicin, hydrogen peroxide, 4-hydroperoxycyclophosphamide, and 1,3-bis (2-chloroethyl)-1-nitrosourea but not to benzoquinone, vinblastine, or gamma-radiation. M1HQ cells possessed significantly higher levels of total thiols, glutathione, glutathione peroxidase, glutathione reductase, quinone reductase, and gamma-glutamyl transpeptidase than the parental M1 cell line. Steady-state gamma-glutamylcysteine synthetase mRNA expression also was 1.6-fold higher in M1HQ cells. P-glycoprotein transcripts were detectable in both M1 and M1HQ cells, but were 2-fold higher in M1HQ. Multidrug resistance-associated protein transcripts were not detectable in either M1 or M1HQ. Hydroquinone resistance in M1HQ cells was partially reversible with a combination of inhibitors of quinone reductase, gamma-glutamylcysteine synthetase, glutathione peroxidase, and the multidrug resistance-associated protein, but not with inhibitors of P-glycoprotein, gamma-glutamyl transpeptidase, or glutathione-S-transferase. When treated with [14C]hydroquinone, M1HQ cells did not generate significant hydroquinone-protein adducts but did release an adduct similar to N-acetylcysteinyl-benzoquinone. In contrast, numerous [14C]hydroquinone-protein adducts were produced in M1 cells, while the N-acetylcysteinyl-benzoquinone-like molecule was undetectable. Thus, hydroquinone resistance in M1HQ cells appeared to result from a glutathione-dependent detoxification and export mechanism.
Colinas
R J
RJ
Wadsworth Center, New York State Department of Health, Albany 12201-0509, USA. colinas@wadsworth.ph.albany.edu
Hunt
D H
DH
Walsh
A C
AC
Lawrence
D A
DA
D000818:Animals; D019008:Drug Resistance, Neoplasm; D006873:Hydroquinones / Q000494:pharmacology*; D007942:Leukemia, Experimental / Q000188:drug therapy*; D051379:Mice; D008815:Mice, Inbred Strains; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects
D006873:Hydroquinones; D011837:Radiation-Protective Agents; C031927:hydroquinone