Estrogen and its metabolites are carcinogenic agents in human breast epithelial cells

Russo, José; Lareef, Mohamed H.; Balogh, Gabriela Andrea; Guo, Shanchun; Russo, Irma H.

doi:10.1016/s0960-0760(03)00390-x

Cited by 238 publications

(229 citation statements)

References 125 publications

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“…Similar data have been reported using 4-hydroxyequilenin 24 in MCF-10A cells, using an anchorage-independent growth assay. In our model the E 2 -mediated phenotypes and genomic changes were not abrogated by the pure antiestrogen ICI182780, 7,9,10 suggesting that in this model the ERa mediated pathway is not involved in neoplastic transformation.Genomic alterations in chromosome 13 and chromosome 17 are known to play an important role in the initiation and progression of human breast cancer. [25][26][27] Chromosome 13 contains the breast cancer susceptibility gene BRCA2 located in chromosome 13q12-q13.…”

mentioning

confidence: 60%

Estradiol and its metabolites 4‐hydroxyestradiol and 2‐hydroxyestradiol induce mutations in human breast epithelial cells

Fernandez

Russo

2005

Intl Journal of Cancer

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110

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An elevated incidence of breast cancer in women has been associated with prolonged exposure to high levels of estrogens. Our laboratory demonstrated that treatment of the immortalized human breast epithelial cells MCF-10F with 17b-estradiol (E 2 ), 4-hydroxyestradiol (4-OHE 2 ) or 2-hydroxyestradiol (2-OHE 2 ) induces phenotypical changes indicative of neoplastic transformation. MCF-10F cells treated with E 2 , 4-OHE 2 or 2-OHE 2 formed colonies in agar methocel and lost their ductulogenic capacity in collagen, expressing phenotypes similar to those induced by the carcinogen benzo[a]pyrene. To investigate whether the transformation phenotypes were associated with genomic changes, cells treated with E 2 , 4-OHE 2 or 2-OHE 2 at different doses were analyzed using microsatellite markers. Since microsatellite instability (MSI) and loss of heterozygosity (LOH) in chromosomes 13 and 17 have been reported in human breast carcinomas, we tested these parameters in MCF-10F cells treated with E 2 , 2-OHE 2 , or 4-OHE 2 alone or in combination with the antiestrogen ICI182780. MCF-10F cells treated with E 2 or 4-OHE 2 , either alone or in combination with ICI182780, exhibited LOH in the region 13q12.3 with the marker D13S893 located at 0.8 cM telomeric to BRCA2. Cells treated with E 2 or 4-OHE 2 at doses of 0.007 and 70 nM and 2-OHE 2 only at a higher dose (3.6 lM) showed a complete loss of 1 allele with D13S893. For chromosome 17, differences were found using the marker TP53-Dint located in exon 4 of p53. Cells treated with E 2 or 4-OHE 2 at doses of 0.007 nM and 70 nM and 2-OHE 2 only at a higher dose (3.6 lM) exhibited a 5 bp deletion in p53 exon 4. Our results show that E 2 and its catechol estrogen metabolites are mutagenic in human breast epithelial cells. ICI182780 did not prevent these mutations, indicating that the carcinogenic effect of E 2 is mainly through its reactive metabolites 4-OHE 2 and 2-OHE 2, with 4-OHE 2 and E 2 being mutagenic at lower doses than 2-OHE 2 . ' 2005 Wiley-Liss, Inc.Key words: breast cancer; estrogen; 4-OHE 2 ; 2-OHE 2 ; cell transformation Breast cancer (BC) is the most commonly occurring neoplasm and the second most frequent cause of cancer death among women in the United States. 1 There is a substantial amount of epidemiological, clinical and experimental evidence pointing to estrogens, e.g. 17b-estradiol (E 2 ), being one of the most important etiological factors for the development and progression of BC. 2-10 The risk factors include high serum or urinary estrogen concentrations, 11-13 the early onset of menstruation, and late menopause, related to prolonged exposure to estrogens. 4,14 Although the precise molecular mechanisms by which E 2 induces breast cancer have not been completely understood, the estrogen implication in breast cancer has been associated mostly with the estrogen receptor (ER) that mediates cell proliferation. 15,16 The direct role of estrogens as tumor initiators has been supported by the evidence that E 2 , catechol estrogens (CEs), and their quinone derivatives ...

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mentioning

confidence: 60%

Estradiol and its metabolites 4‐hydroxyestradiol and 2‐hydroxyestradiol induce mutations in human breast epithelial cells

Fernandez

Russo

2005

Intl Journal of Cancer

Self Cite

110

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“…To mimic intermittent exposure of immortalized MCF-10F cells to estrogen [22,23], the cells were successively treated with 0.2 or 0.5 μM 4-OHE 2 twice a week for two weeks (Tables 1 and 2). The cell culture medium was removed 24 h after each treatment and processed for analysis of estrogen metabolites, conjugates and depurinating DNA adducts.…”

Section: Resultsmentioning

confidence: 99%

“…Experiments on estrogen metabolism [6][7][8][9][10], formation of DNA adducts [11][12][13][14][15][16][17], mutagenicity [17][18][19][20][21], cell transformation [22][23][24] and carcinogenicity [25][26][27][28] have led to the hypothesis that certain estrogen metabolites, predominantly catechol estrogen-3,4-quinones, react with DNA to cause the mutations leading to the initiation of cancer ( Fig. 1) [17].…”

Section: Introductionmentioning

confidence: 99%

Inhibition of catechol-O-methyltransferase increases estrogen–DNA adduct formation

Zahid

Saeed

et al. 2007

Free Radical Biology and Medicine

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The association found between breast cancer development and prolonged exposure to estrogens suggests that this hormone is of etiologic importance in the causation of the disease. Studies on estrogen metabolism, formation of DNA adducts, carcinogenicity, cell transformation and mutagenicity have led to the hypothesis that reaction of certain estrogen metabolites, predominantly catechol estrogen-3,4-quinones, with DNA forms depurinating adducts [4-OHE 1 (E 2 )-1-N3Ade and 4-OHE 1 (E 2 )-1-N7Gua]. These adducts cause mutations leading to the initiation of breast cancer. Catechol-O-methyltransferase (COMT) is considered an important enzyme that protects cells from the genotoxicity and cytotoxicity of catechol estrogens, by preventing their conversion to quinones. The goal of the present study was to investigate the effect of COMT inhibition on the formation of depurinating estrogen-DNA adducts. Immortalized human breast epithelial MCF-10F cells were treated with 4-OHE 2 (0.2 or 0.5 μM) for 24 h at 120, 168, 216, and 264 h post-plating or one time at 1-30 μM 4-OHE 2 with or without the presence of COMT inhibitor (Ro41-0960). The culture media were collected at each point, extracted by solid-phase extraction and analyzed by HPLC connected with a multichannel electrochemical detector. The results demonstrate that MCF-10F cells oxidize 4-OHE 2 to E 1 (E 2 )-3,4-Q, which react with DNA to form the depurinating N3Ade and N7Gua adducts. The COMT inhibitor Ro41-0960 blocked the methoxylation of catechol estrogens, with concomitant 3-4 fold increases in the levels of the depurinating adducts. Thus, low activity of COMT leads to higher levels of depurinating estrogen-DNA adducts that can induce mutations and initiate cancer.

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“…An approximately million times higher concentration of 2-OHE 2 is needed to transform these cells (22,23). Transformation occurs even in the presence of the antiestrogen ICI-182,780 (24), indicating that transformation does not proceed through estrogen receptor-mediated events (25).…”

Section: Discussionmentioning

confidence: 99%

“…These adducts generate apurinic sites that may lead to cancer-initiating mutations (17)(18)(19), which transform cells (22)(23)(24)(25), thereby initiating cancer.…”

Section: Introductionmentioning

confidence: 99%

The Greater Reactivity of Estradiol-3,4-quinone vs Estradiol-2,3-quinone with DNA in the Formation of Depurinating Adducts: Implications for Tumor-Initiating Activity

Zahid

Kohli

Saeed

et al. 2005

Chem. Res. Toxicol.

151

207

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Strong evidence supports the idea that specific metabolites of estrogens, mainly catechol estrogen-3,4-quinones, can react with DNA to become endogenous initiators of breast, prostate, and other human cancers. Oxidation of the catechol estrogen metabolites 4-hydroxyestradiol (4-OHE 2 ) and 2-OHE 2 leads to the quinones, estradiol-3,4-quinone (E 2 -3,4-Q) and estradiol-2,3-quinone (E 2 -2,3-Q), respectively. The reaction of E 2 -3,4-Q with DNA affords predominantly the depurinating adducts 4-OHE 2 -1-N3Ade and 4-OHE 2 -1-N7Gua, whereas the reaction of E 2 -2,3-Q with DNA yields the newly synthesized depurinating adduct 2-OHE 2 -6-N3Ade. The N3Ade adducts are lost from DNA by rapid depurination, while the N7Gua adduct is lost from DNA with a half-life of ∼3 h at 37°C. To compare the relative reactivity of E 2 -3,4-Q and E 2 -2,3-Q, the compounds were reacted individually with DNA for 0.5-20 h at 37°C, as well as in mixtures (3:1, 1:1, 1:3, and 5:95) for 10 h at 37°C. Depurinating and stable adducts were analyzed. In similar experiments, the relative reactivity of 4-OHE 2 and 2-OHE 2 with DNA was determined after activation by lactoperoxidase, tyrosinase, prostaglandin H synthase (PHS), or 3-methylcholanthreneinduced rat liver microsomes. Starting with the quinones, the levels of depurinating adducts formed from E 2 -3,4-Q were much higher than that of the depurinating adduct from E 2 -2,3-Q. Similar results were obtained with lactoperoxidase or tyrosinase-catalyzed oxidation of 4-OHE 2 and 2-OHE 2 , whereas with activation by PHS or microsomes, a relatively higher amount of the depurinating adduct from E 2 -2,3-Q was detected. These results demonstrate that the E 2 -3,4-Q is much more reactive with DNA than E 2 -2,3-Q. The relative reactivities of E 2 -3,4-Q and E 2 -2,3-Q to form depurinating adducts correlate with the carcinogenicity, mutagenicity, and cell-transforming activity of their precursors, the catechol estrogens 4-OHE 2 and 2-OHE 2 . This is essential information for understanding the cancer risk posed by oxidation of the two catechol estrogens.

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Estrogen and its metabolites are carcinogenic agents in human breast epithelial cells

Cited by 238 publications

References 125 publications

Estradiol and its metabolites 4‐hydroxyestradiol and 2‐hydroxyestradiol induce mutations in human breast epithelial cells

Estradiol and its metabolites 4‐hydroxyestradiol and 2‐hydroxyestradiol induce mutations in human breast epithelial cells

Inhibition of catechol-O-methyltransferase increases estrogen–DNA adduct formation

The Greater Reactivity of Estradiol-3,4-quinone vs Estradiol-2,3-quinone with DNA in the Formation of Depurinating Adducts: Implications for Tumor-Initiating Activity

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