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Hormone replacement therapy dependent changes in breast cancer-related gene expression in breast tissue of healthy postmenopausal women.

ABSTRACT: Risk assessment of future breast cancer risk through exposure to sex steroids currently relies on clinical scorings such as mammographic density. Knowledge about the gene expression patterns in existing breast cancer tumors may be used to identify risk factors in the breast tissue of women still free of cancer. The differential effects of estradiol, estradiol together with gestagens, or tibolone on breast cancer-related gene expression in normal breast tissue samples taken from postmenopausal women may be used to identify gene expression profiles associated with a higher breast cancer risk. Breast tissue samples were taken from 33 healthy postmenopausal women both before and after a six month treatment with either 2mg micronized estradiol [E2], 2mg micronized estradiol and 1mg norethisterone acetate [E2+NETA], 2.5mg tibolone [T] or [no HRT]. Except for [E2], which was only given to women after hysterectomy, the allocation to each of the three groups was randomized. The expression of 102 mRNAs and 46 microRNAs putatively involved in breast cancer was prospectively determined in the biopsies of 6 women receiving [no HRT], 5 women receiving [E2], 5 women receiving [E2+NETA], and 6 receiving [T]. Using epithelial and endothelial markers genes, non-representative biopsies from 11 women were eliminated. Treatment of postmenopausal women with [E2+NETA] resulted in the highest number of differentially (p<0.05) regulated genes (16.2%) compared to baseline, followed by [E2] (10.1%) and [T] (4.7%). Among genes that were significantly down-regulated by [E2+NETA] ranked estrogen-receptor-1 (ESR1, p=0.019) and androgen receptor (AR, p=0.019), whereas CYP1B1, a gene encoding an estrogen-metabolizing enzyme, was significantly up-regulated (p=0.016). Mammary cells triggered by [E2+NETA] and [E2] adjust for steroidogenic up-regulation through down-regulation of the estrogen-receptor pathway. In this prospective study, prolonged administration of [E2+NETA] and to a lesser extent of [E2] but not [T] were associated in otherwise healthy breast tissue with a change in the expression of genes putatively involved in breast cancer. Our data suggest that normal mammary cells triggered by [E2+NETA] adjust for steroidogenic up-regulation through down-regulation of the estrogen-receptor pathway. This feasibility study provides the basis for whole genome analyses to identify novel markers involved in increased breast cancer risk.

SUBMITTER: Sieuwerts AM

PROVIDER: S-EPMC5528323 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature

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Hormone replacement therapy dependent changes in breast cancer-related gene expression in breast tissue of healthy postmenopausal women.

Sieuwerts Anieta M AM De Napoli Giuseppina G van Galen Anne A Kloosterboer Helenius J HJ de Weerd Vanja V Zhang Hong H Martens John W M JW Foekens John A JA De Geyter Christian C

Molecular oncology 20110916 6

Risk assessment of future breast cancer risk through exposure to sex steroids currently relies on clinical scorings such as mammographic density. Knowledge about the gene expression patterns in existing breast cancer tumors may be used to identify risk factors in the breast tissue of women still free of cancer. The differential effects of estradiol, estradiol together with gestagens, or tibolone on breast cancer-related gene expression in normal breast tissue samples taken from postmenopausal wo ...[more]

PMID: 21956102

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Project description:Title: Transcriptome analysis of human endometrial tissues from healthy post-menoupausal women reflecting the endometrial response to 3-weeks treatment with tibolone, E2 and E2+MPA. In an observational, open, non-randomized, controlled study uterine tissues were collected in order to generate endometrial gene expression profiles. healthy postmenopausal women were enrolled into the following treatment groups: Control-group; Tibolone-group, 2,5 mg of tibolone (administered orally) every day, starting 21 days prior to surgery; Estradiol-group, 2 mg of estradiol (administered orally) every day, starting 21 days prior to surgery; Estradiol+progestagen-group, 2 mg of estradiol (administered orally) and 5 mg of MPA (Medroxy Progesteroneacetate, administered orally) every day, starting 21 days prior to surgery. Pure (100%) endometrium was isolated from the snap-frozen uterine tissues and used for RNA isolation. RNA was labeled and hybridized to whole genome Affymetrix U133plus2 GeneChips containing 54,614 probe sets, representing approximately 47,000 transcripts. Relative to the control group, 940 genes are regulated in the endometrium of E2 treated patients, whereas only 198 genes are significantly regulated in endometria from tibolone or E2+MPA treated patients. Furthermore, only 9% of E2 regulated genes are also regulated by tibolone (85 out of 940), only 5% are also regulated by E2+MPA treatment and the overlap between tibolone and E2+MPA treatment is about 10%. This indicated that tibolone-treatment results in a weak endometrial profile similarity to E2 treatment and no profile similarity to E2+MPA treatment. A more detailed analysis showed that down stream processes, such as regulation of the cell cycle, angiogenesis and cell proliferation are almost not affected by tibolone treatment but, in contrast, are significantly affected by E2. For example, upon staining with Ki67, a marker for mitotic activity, significantly increased stromal as well as glandular cell proliferation was observed in the endometria from the E2-only treated group, while tibolone treatment resulted only in a slight increase in stromal cell proliferation (and no increase in glandular cell proliferation). These results indicate that in contrast to long-term tibolone use, short-term (21-days) use results in some estrogenic stimulation of the endometrium, which is clearly far less and rather different from what is observed during E2 treatment. References: Klaassens et al., 2006 Hanifi-Moghaddam et al., 2007 Verheul et al., 2007

Project description:ImportanceMenopause is associated with biological aging, and hormone therapy (HT) is associated with health outcomes in postmenopausal women.ObjectiveTo evaluate the association between HT use and discrepancies between chronological and biological age in postmenopausal women as well as the potential modifying role of socioeconomic status (SES).Design, setting, and participantsThis population-based, retrospective cohort study included postmenopausal women registered in the UK Biobank. A baseline survey on HT use and biological aging biomarkers was conducted from March 2006 to October 2010. Data analyses were conducted in December 2023.ExposuresInformation regarding HT use, the age at starting HT, and HT duration was collected via a touchscreen questionnaire. SES was evaluated by education, family income, occupation, and the Townsend Deprivation Index.Main outcomes and measuresBiological aging discrepancy was evaluated using validated phenotypic age, which was calculated using chronological age and 9 biomarkers measured at baseline. All-cause and cause-specific mortality were also assessed.ResultsAmong the 117 763 postmenopausal women (mean [SD] age, 60.2 [5.4] years), 47 461 (40.3%) ever used HT. The mean phenotypic age was 52.1 (7.9) years. Ever use of HT was associated with a smaller biological aging discrepancy than never use of HT (β, -0.17 years; 95% CI, -0.23 to -0.10 years). This smaller aging discrepancy was more evident in those who started HT at age 55 years or older (β, -0.32 years; 95% CI, -0.48 to -0.15 years) and in those who used HT for 4 to 8 years (β, -0.25 years; 95% CI, -0.35 to -0.15 years). The association between HT and a smaller aging discrepancy was more evident in women with low SES, with a significant interaction observed for education (higher education: β, -0.08 years [95% CI, -0.17 to 0.01]; other education: β, -0.23 [95% CI, -0.32 to -0.14] years; P for interaction = .02). Phenotypic aging discrepancy mediated 12.7% (95% CI, 6.3% to 23.9%) of the association between HT and all-cause mortality and cause-specific mortality.Conclusions and relevanceIn this study, postmenopausal women with historical HT use were biologically younger than those not receiving HT, with a more evident association observed in those with low SES. The biological aging discrepancy mediated the association between HT and decreased mortality. Promoting HT in postmenopausal women could be important for healthy aging.

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Hormone replacement therapy dependent changes in breast cancer-related gene expression in breast tissue of healthy postmenopausal women.

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Hormone replacement therapy dependent changes in breast cancer-related gene expression in breast tissue of healthy postmenopausal women.

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