Carcinogenesis, Vol 19, 861-866, Copyright © 1998 by Oxford University Press
W Davis, S Venitt and DH Phillips
The biotransformation pathway of tamoxifen and alpha-hydroxytamoxifen to
DNA-binding species was investigated in rat hepatocytes in vitro. Rat
hepatocytes were isolated by in situ collagenase perfusion and then
maintained in sulphate-free Dulbecco's modified Eagle's medium. Magnesium
sulphate was added to the medium to give concentrations of 0- 10 microM,
prior to treatment for 18 h with solvent vehicle (DMSO), tamoxifen (10
microM), alpha-hydroxytamoxifen (1 microM) or benzo[a]pyrene (BaP) (10 and
50 microM). DNA was isolated and analysed by 32P-post-labelling. For
tamoxifen and alpha-hydroxytamoxifen, the level of DNA adduct formation was
directly proportional to the concentration of sulphate in the medium.
Between 0 and 10 microM MgSO4, the DNA adduct level increased 10-fold with
both compounds. Rat hepatocytes were also maintained in normal Dulbecco's
modified Eagle's medium and pretreated with
dehydroisoandrosterone-3-sulphate (DHEAS, a sulphotransferase inhibitor) at
concentrations ranging from 0-1 mM, prior to treatment with solvent vehicle
(DMSO), tamoxifen (10 microM), alpha-hydroxytamoxifen (1 microM) or BaP (50
microM). For tamoxifen and alpha-hydroxytamoxifen the level of DNA adducts
was reduced to approximately one-fifth by the addition of DHEAS (0.1 mM).
BaP-DNA adduct formation, which proceeds by a pathway that does not require
sulphation, was not significantly affected by sulphate concentration or by
addition of DHEAS, which demonstrates that the general metabolic capacity
and viability of the hepatocytes were not compromised. It is concluded that
the activation of tamoxifen in rat liver cells to DNA binding products
proceeds predominantly through hydroxylation followed by sulphate ester
formation at the alpha-position of the ethyl side chain.
ARTICLES
The metabolic activation of tamoxifen and alpha-hydroxytamoxifen to DNA- binding species in rat hepatocytes proceeds via sulphation
Section of Molecular Carcinogenesis, Institute of Cancer Research, Haddow Laboratories, Sutton, Surrey, UK. warren@icr.ac.uk
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
K. Brown Is tamoxifen a genotoxic carcinogen in women? Mutagenesis, September 1, 2009; 24(5): 391 - 404. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Liapis, K. I.E. McLuckie, P. D. Lewis, P. B. Farmer, and K. Brown Mutagenicity of tamoxifen DNA adducts in human endometrial cells and in silico prediction of p53 mutation hotspots Nucleic Acids Res., October 1, 2008; 36(18): 5933 - 5945. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Brown, E. M. Tompkins, D. J. Boocock, E. A. Martin, P. B. Farmer, K. W. Turteltaub, E. Ubick, D. Hemingway, E. Horner-Glister, and I. N.H. White Tamoxifen Forms DNA Adducts in Human Colon after Administration of a Single [14C]-Labeled Therapeutic Dose Cancer Res., July 15, 2007; 67(14): 6995 - 7002. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Y. Kim, Y. R. S. Laxmi, N. Suzuki, K. Ogura, T. Watabe, M. W. Duffel, and S. Shibutani FORMATION OF TAMOXIFEN-DNA ADDUCTS VIA O-SULFONATION, NOT O-ACETYLATION, OF {alpha}-HYDROXYTAMOXIFEN IN RAT AND HUMAN LIVERS Drug Metab. Dispos., November 1, 2005; 33(11): 1673 - 1678. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. H. Phillips, A. Hewer, M. R. Osborne, K. J. Cole, C. Churchill, and V. M. Arlt Organ specificity of DNA adduct formation by tamoxifen and {alpha}-hydroxytamoxifen in the rat: implications for understanding the mechanism(s) of tamoxifen carcinogenicity and for human risk assessment Mutagenesis, July 1, 2005; 20(4): 297 - 303. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. I. Apak and M. W. Duffel INTERACTIONS OF THE STEREOISOMERS OF {alpha}-HYDROXYTAMOXIFEN WITH HUMAN HYDROXYSTEROID SULFOTRANSFERASE SULT2A1 AND RAT HYDROXYSTEROID SULFOTRANSFERASE STA Drug Metab. Dispos., December 1, 2004; 32(12): 1501 - 1508. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. J. Boocock, K. Brown, A. H. Gibbs, E. Sanchez, K. W. Turteltaub, and I. N.H. White Identification of human CYP forms involved in the activation of tamoxifen and irreversible binding to DNA Carcinogenesis, November 1, 2002; 23(11): 1897 - 1902. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Chen, G. Gamboa da Costa, M.M. Marques, S. D. Shelton, F. A. Beland, and M. G. Manjanatha Mutations induced by {alpha}-hydroxytamoxifen in the lacI and cII genes of Big Blue transgenic rats Carcinogenesis, October 1, 2002; 23(10): 1751 - 1758. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Gamboa da Costa, L.P. McDaniel-Hamilton, R. H. Heflich, M.M. Marques, and F. A. Beland DNA adduct formation and mutant induction in Sprague-Dawley rats treated with tamoxifen and its derivatives Carcinogenesis, August 1, 2001; 22(8): 1307 - 1315. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. H. Phillips Understanding the genotoxicity of tamoxifen? Carcinogenesis, June 1, 2001; 22(6): 839 - 849. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. N.H. White, P. Carthew, R. Davies, J. Styles, K. Brown, J. E. Brown, L. L. Smith, and E. A. Martin Short-term dosing of {{alpha}}-hydroxytamoxifen results in DNA damage but does not lead to liver tumours in female Wistar/Han rats Carcinogenesis, April 1, 2001; 22(4): 553 - 557. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. J. Boocock, J. L. Maggs, K. Brown, I. N.H. White, and B.K. Park Major inter-species differences in the rates of O-sulphonation and O-glucuronylation of {alpha}-hydroxytamoxifen in vitro: a metabolic disparity protecting human liver from the formation of tamoxifen-DNA adducts Carcinogenesis, October 1, 2000; 21(10): 1851 - 1858. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Umemoto, Y. Monden, M. Suwa, Y. Kanno, M. Suzuki, C.-X. Lin, Y. Ueyama, Md.A. Momen, A. Ravindernath, S. Shibutani, et al. Identification of hepatic tamoxifen-DNA adducts in mice: {alpha}-(N2-deoxyguanosinyl)tamoxifen and {alpha}-(N2-deoxyguanosinyl)tamoxifen N-oxide Carcinogenesis, September 1, 2000; 21(9): 1737 - 1744. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Shibutani, A. Ravindernath, N. Suzuki, I. Terashima, S. M. Sugarman, A. P. Grollman, and M. L. Pearl Identification of tamoxifen-DNA adducts in the endometrium of women treated with tamoxifen Carcinogenesis, August 1, 2000; 21(8): 1461 - 1467. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Davis, A. Hewer, K. M. Rajkowski, W. Meinl, H. Glatt, and D. H. Phillips Sex Differences in the Activation of Tamoxifen to DNA Binding Species in Rat Liver in Vivo and in Rat Hepatocytes in Vitro: Role of Sulfotransferase Induction Cancer Res., June 1, 2000; 60(11): 2887 - 2891. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Bartsch, D. H. Phillips, J. Nair, A. Hewer, G. Meyberg-Solomeyer, and E.-M. Grischke Lack of evidence for tamoxifen- and toremifene-DNA adducts in lymphocytes of treated patients Carcinogenesis, April 1, 2000; 21(4): 845 - 847. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. H. Phillips, A. Hewer, M. N. Horton, K. J. Cole, P. L. Carmichael, W. Davis, and M. R. Osborne N-Demethylation accompanies {alpha}-hydroxylation in the metabolic activation of tamoxifen in rat liver cells Carcinogenesis, October 1, 1999; 20(10): 2003 - 2009. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Brown, R. T. Heydon, R. Jukes, I. N.H. White, and E. A. Martin Further characterization of the DNA adducts formed in rat liver after the administration of tamoxifen, N-desmethyltamoxifen or N,N-didesmethyltamoxifen Carcinogenesis, October 1, 1999; 20(10): 2011 - 2016. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. N.H. White The tamoxifen dilemma Carcinogenesis, July 1, 1999; 20(7): 1153 - 1160. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. R. Osborne, A. Hewer, W. Davis, A. J. Strain, A. Keogh, I. R. Hardcastle, and D. H. Phillips Idoxifene derivatives are less reactive to DNA than tamoxifen derivatives, both chemically and in human and rat liver cells Carcinogenesis, February 1, 1999; 20(2): 293 - 297. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Rajaniemi, I. Rasanen, P. Koivisto, K. Peltonen, and K. Hemminki Identification of the major tamoxifen–DNA adducts in rat liver by mass spectroscopy Carcinogenesis, February 1, 1999; 20(2): 305 - 309. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. L. Carmichael, S. Sardar, N. Crooks, P. Neven, I. Van Hoof, A. Ugwumadu, T. Bourne, E. Tomas, P. Hellberg, A. J. Hewer, et al. Lack of evidence from HPLC 32P-post-labelling for tamoxifen–DNA adducts in the human endometrium Carcinogenesis, February 1, 1999; 20(2): 339 - 342. [Abstract] [Full Text] [PDF] |
||||




