Project description:Full-term pregnancy (FTP) at an early age confers long-term protection against breast cancer, in this study, we evaluated gene expression changes induced by parity in the breast of premenopausal women. Gene expression profiling of normal breast tissue from 30 nulliparous (NP) and 79 parous (P) premenopausal volunteers were performed using Affymetrix microarrays. In addition to a discovery/validation analysis, we conducted analysis of gene expression differences in P vs. NP women as a function of time since last FTP.
Project description:It is widely accepted that a womanâs lifetime risk of developing breast cancer at menopause is reduced by early full term pregnancy and multiparity. This phenomenon is associated with the development and differentiation of the breast, which ultimately imprints a specific genomic profile in the mammary epithelium. In the present work we demonstrate that this profile represents a permanent signature that could be associated with the breast cancer risk reduction conferred by pregnancy. We have compared the gene expression profile of normal breast biopsies performed in 71 parous (P) and 42 nulliparous (NP) postmenopausal women. All samples were hybridized to Affymetrix HG_U133 Plus 2.0 oligonucleotide arrays. We compared the gene expression profile of normal breast core biopsies from 71 parous (women that had a full term pregnancy) and 42 nulliparous (women that never completed a pregnancy) postmenopausal women from Sweden. All samples were hybridized to Affymetrix HG_U133 Plus 2.0 oligonucleotide arrays.
Project description:Breast cancer is a leading cause of death in premenopausal women. Progesterone drives expansion of luminal progenitor cells, leading to the development of poor-prognostic breast cancers. However, it is not known if antagonising progesterone can prevent breast cancers in humans. We suggest that targeting progesterone signalling could be a means of reducing features which are known to promote breast cancer formation.
Project description:It is widely accepted that a woman’s lifetime risk of developing breast cancer at menopause is reduced by early full term pregnancy and multiparity. This phenomenon is associated with the development and differentiation of the breast, which ultimately imprints a specific genomic profile in the mammary epithelium. In the present work we demonstrate that this profile represents a permanent signature that could be associated with the breast cancer risk reduction conferred by pregnancy. We have compared the gene expression profile of normal breast biopsies performed in 71 parous (P) and 42 nulliparous (NP) postmenopausal women. All samples were hybridized to Affymetrix HG_U133 Plus 2.0 oligonucleotide arrays.
Project description:Kreike et al, have constructed a gene-expression (GE) profile predictive for local recurrence (LR) after breast-conserving treatment (BCT) from a series of 165 patients . This study aimed to test this signature both internally (cross-platform) and externally on a independent series and to further explore the search for a GE signature of breast cancer LR in young women.
Project description:The aim of the experiment was to identify the change of gene expression in human ovaries between premenopausal women and postmenopausal women based on DNA microarrays analysis. 8 human ovary samples were assembled from premenopausal women (n=4) and from postmenopausal women (n=4), respectively. The active transcription profiles of human ovaries were identified through DNA microarrays. Differentially expressed genes (DEGs) were identified as at least two-fold change with statistical significance. Enrichment of functions and signaling pathways analysis were performed based on Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes database.
Project description:The objective of the study was to comprehensively compare the genomic profiles in the breast of parous and nulliparous postmenopausal women to identify genes that permanently change their expression following pregnancy. The study was designed as a two-phase approach. In the discovery phase, we compared breast genomic profiles of 37 parous with 18 nulliparous postmenopausal women. In the validation phase, confirmation of the genomic patterns observed in the discovery phase was sought in an independent set of 30 parous and 22 nulliparous postmenopausal women.
Project description:Five years of tamoxifen reduces breast cancer risk by nearly 50% but is associated with significant side-effects and toxicities. A better understanding of the direct and indirect effects of tamoxifen in benign breast tissue could elucidate new mechanisms of breast carcinogenesis, suggest novel chemoprevention targets, and provide relevant early response biomarkers for Phase II prevention trials. Seventy-three women at increased risk for breast cancer were randomized to tamoxifen (20 mg daily) or placebo for three months. Blood and breast tissue samples were collected at baseline and post-treatment. Sixty-nine women completed all study activities (37 tamoxifen and 32 placebo). The selected biomarkers focused on estradiol and IGFs in the blood, DNA methylation and cytology in random periareolar fine needle aspirates, and tissue morphometry, proliferation, apoptosis, and gene expression (microarray and RT-PCR) in the tissue core samples. Tamoxifen downregulated ets-oncogene family members ETV4 and ETV5 and reduced breast epithelial cell proliferation independent of CYP2D6 genotypes or effects on estradiol, ESR1 or IGFs. Reduction in proliferation was correlated with downregulation of ETV4 and DNAJC12. Tamoxifen also modulated expression of RAB GTPases, and several genes involved in epithelial-stromal interaction, and reduced tumor suppressor gene methylation. Three months of tamoxifen did not affect breast tissue composition, cytological atypia, preneoplasia or apoptosis. Tamoxifen may durably reduce breast cancer risk through downregulation of ETV4 and ETV5 which could deplete mammary progenitor populations. This pathway has the potential to provide novel targets and early response biomarkers for phase II prevention trials. Randomized prospective double blinded placebo-controlled trial of tamoxifen (20 mg daily) versus placeo in women at increased risk for breast cancer. Gene expression was assessed in whole breast tissue cores obtained at baseline and after three months of treatment for 35 women. Core biopsies were obtained in the late luteal phase (day 28 +/- 2) for premenopausal women (N = 19). Breast lobules from the baseline and post-treatment cores were microdissected for 5 tamoxifen subjects.
Project description:Case-control study for the analysis of the gene expression profile of epithelial cells microdissected from normal breast tissues obtained from 17 parous and 7 nulliparous women free of breast pathology (controls), and 39 parous and 8 nulliparous women with history of breast cancer (cases). Keywords: genetic modifications
Project description:To investigate molecular changes in skeletal muscle cells after exercise in premenopausal women and to identify potential relevance for the anti-cancer effect of cancer.