Recent insight on the control of enzymes involved in estrogen formation and transformation in human breast cancer

Pasqualini, Jörge R.; Chétrite, G.

doi:10.1016/j.jsbmb.2005.02.007

Cited by 177 publications

(160 citation statements)

References 152 publications

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“…Among postmenopausal women, the concentration of 17β-estradiol in breast tumors is at least 20-fold higher than that in the circulation, but among premenopausal women with breast cancer, this difference was only five-fold (Pasqualini et al, 2005). In vitro experiments also have shown that isoflavones inhibit the activity of aromatase and 17β-hydroxysteroid dehydrogenases involved in the synthesis of estradiol from circulating androgens and estrones (Brooks et al, 2005;Lacey et al, 2005).…”

Section: Discussionmentioning

confidence: 99%

Post-diagnosis Soy Food Intake and Breast Cancer Survival: A Meta-analysis of Cohort Studies

Chi

Wu²,

Zeng³

et al. 2013

Asian Pacific Journal of Cancer Prevention

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Background and Objectives: Data on associations between soy food intake after cancer diagnosis with breast cancer survival are conflicting, so we conducted this meta-analysis for more accurate evaluation. Methods: Comprehensive searches were conducted to find cohort studies of the relationship between soy food intake after cancer diagnosis and breast cancer survival. Data were analyzed with comprehensive meta-analysis software.

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Section: Discussionmentioning

confidence: 99%

Post-diagnosis Soy Food Intake and Breast Cancer Survival: A Meta-analysis of Cohort Studies

Chi

Wu²,

Zeng³

et al. 2013

Asian Pacific Journal of Cancer Prevention

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“…Ovaries are the main sites of oestrogen synthesis in premenopausal non-pregnant women. However, after menopause, local synthesis of oestrogens in some tissues, including mammary tissue, acquires a special importance in mammary carcinogenesis (Ackerman et al, 1981;Pasqualini, 2004;Pasqualini and Chetrite, 2005;Suzuki et al, 2005). The local synthesis of oestrogens depends on the activity of different enzyme families (aromatase, sulfatases, etc) to transform androgens into oestrogens, as well as compounds of weak oestrogenic activity into more active forms.…”

Section: Discussionmentioning

confidence: 99%

Melatonin inhibits aromatase promoter expression by regulating cyclooxygenases expression and activity in breast cancer cells

et al. 2009

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BACKGROUND: Melatonin reduces the development of breast cancer interfering with oestrogen-signalling pathways, and also inhibits aromatase activity and expression. Our objective was to study the promoters through which melatonin modifies aromatase expression, evaluate the ability of melatonin to regulate cyclooxygenases and assess whether the effects of melatonin are related to its effects on intracellular cAMP, in MCF-7 cells. METHODS: Total aromatase mRNA, aromatase mRNA promoter regions and cyclooxygenases mRNA expression were determined by real-time RT -PCR. PGE 2 and cAMP were measured by kits. RESULTS: Melatonin downregulated the gene expression of the two major specific aromatase promoter regions, pII and pI.3, and also that of the aromatase promoter region pI.4. Melatonin 1 nM was able to counteract the stimulatory effect of tetradecanoyl phorbol acetate on PGE 2 production and inhibit COX-2 and COX-1 mRNA expression. Melatonin 1 nM elicited a parallel time-dependent decrease in both cyclic AMP formation and aromatase mRNA expression. CONCLUSIONS: This study shows that melatonin inhibits aromatase activity and expression by regulating the gene expression of specific aromatase promoter regions. A possible mechanism for these effects would be the regulation by melatonin of intracellular cAMP levels, mediated by an inhibition of cyclooxygenase activity and expression.

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“…Therefore, since both Tib and raloxifene were readily sulfated by human tissues the regulation of the levels of these sulfates may be critical in regulating their physiological functions especially in target tissues (12,13). Although conjugation with a sulfonate group is generally an inactivation process, sulfation is a reversible process since many sulfate esters can be hydrolyzed by STS activity (31,32). Desulfation regenerates the active form of the compound and renders it capable of exerting a biological effect.…”

Section: Discussionmentioning

confidence: 99%

Interactions of the human cytosolic sulfotransferases and steroid sulfatase in the metabolism of tibolone and raloxifene

Falany

2007

The Journal of Steroid Biochemistry and Molecular Biology

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Sulfation is important in the metabolism and inactivation of steroidal compounds and hormone replacement therapeutic (HRT) agents in human tissues. Although generally inactive, many steroid sulfates are hydrolyzed to their active forms by sulfatase activity. Therefore, the specific sulfotransferase (SULT) isoforms and the levels of steroid sulfatase (STS) activity in tissues are important in regulating the activity of steroidal and HRT compounds. Tibolone (Tib) is metabolized to three active metabolites and all four compounds are readily sulfated. Tib and the Δ4-isomer are sulfated at the 17β-OH group by SULT2A1 and the 17-sulfates are resistant to hydrolysis by human placental STS. 3α-OH and 3β-OH Tib can form both 3-and 17-monosulfates as well as disulfates. Only the 3β-sulfates are susceptible to STS hydrolysis. Raloxifene monosulfation was catalyzed by at least seven SULT isoforms and SULT1E1 also synthesizes raloxifene disulfate. SULT1E1 forms both monosulfates in a ratio of approximately 8:1 with the more abundant monosulfate migrating on HPLC identical to the SULT2A1 synthesized monosulfate. The raloxifene monosulfate formed by both SULT isoforms is sensitive to STS hydrolysis whereas the low abundance monosulfate formed by SULT1E1 is resistant. The benzothiophene sulfates of raloxifene and arzoxifene were hydrolyzed by STS whereas the raloxifene 4′-phenolic sulfate was resistant. These results indicate that tissue specific expression of SULT isoforms and STS could be important in the inactivation and regeneration of the active forms of HRT agents.

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Recent insight on the control of enzymes involved in estrogen formation and transformation in human breast cancer

Cited by 177 publications

References 152 publications

Post-diagnosis Soy Food Intake and Breast Cancer Survival: A Meta-analysis of Cohort Studies

Post-diagnosis Soy Food Intake and Breast Cancer Survival: A Meta-analysis of Cohort Studies

Melatonin inhibits aromatase promoter expression by regulating cyclooxygenases expression and activity in breast cancer cells

Interactions of the human cytosolic sulfotransferases and steroid sulfatase in the metabolism of tibolone and raloxifene

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