title: The effect of dimethyl sulfoxide on the function of cytochrome P450 2D6 in HepG2 cells upon the co-expression with NADPH-cytochrome P450 reductase.
abstract: HepG2 cells, a human hepatoma cell line, stably expressing NADPH-cytochrome P450 reductase (OR) and/or cytochrome P450 2D6 wild-type (CYP2D6-WT) or its variants (Pro34Ser, Gly42Arg, Arg296Cys and Ser486Thr) were established in the present study. The cultivation of HepG2 cells expressing CYP2D6-WT in the culture medium containing dimethyl sulfoxide (DMSO, 0.1% of final concentration) markedly increased the bufuralol (BF) 1''-hydroxylase activity compared with that of control cells when cultivated without DMSO. A similar effect was also observed in HepG2 cells stably expressing CYP2D6 and OR. The addition of hemin in place of DMSO to the culture medium resulted in no increase in the enzyme activity. Western blot analysis revealed that the levels of CYP2D6 protein were similar between DMSO-treated and non-treated HepG2 cells regardless of OR expression. Spectrophotometric analysis of reduced carbon monoxide-difference spectra of HepG2 cells expressing CYP2D6-WT and/or OR demonstrated that the addition of DMSO increased the peak height of functional CYP2D6 at 450 nm. These results suggest that the increase in CYP2D6 activity is attributable to the radical-scavenging effect of DMSO. The HepG2 cell lines stably expressing OR and CYP2D6 or its variants in combination with DMSO treatment may be useful for screening the cytotoxicity of chemical compounds which undergo oxidation by CYP2D6.
authors.affiliation: Laboratory of Health Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Okayama 700-8530, Japan. shizuo@pharm.okayama-u.ac.jp
authors.forename: Shizuo
authors.initials: S
authors.lastname: Narimatsu
authors.forename: Noriko
authors.initials: N
authors.lastname: Takatsu
authors.forename: Shigeru
authors.initials: S
authors.lastname: Yamano
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Inoue
authors.forename: Nobumitsu
authors.initials: N
authors.lastname: Hanioka
authors.forename: Kimio
authors.initials: K
authors.lastname: Kiryu
authors.forename: Shinsaku
authors.initials: S
authors.lastname: Naito
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Gonzalez
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yamamoto
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics / Q000378:metabolism*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D006900:Hydroxylation; D009251:NADPH-Ferrihemoprotein Reductase / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D019389:Cytochrome P-450 CYP2D6; D009251:NADPH-Ferrihemoprotein Reductase; D004121:Dimethyl Sulfoxide