Project description:This SuperSeries is composed of the SubSeries listed below. Gene expression profiling of continuous or intermittent energy restriction in women at increased risk of breast cancer
Project description:Dietary energy restriction (DER) reduces risk of spontaneous mammary cancer in rodents. In humans, DER in premenopausal years seems to reduce risk of postmenopausal breast cancer. Markers of DER are required to develop acceptable DER regimens for breast cancer prevention. We therefore examined markers of DER in the breast, adipose tissue, and serum. Nineteen overweight or obese women at moderately increased risk of breast cancer (lifetime risk, 1 in 6 to 1 in 3) ages between 35 and 45 were randomly allocated to DER [liquid diet, 3,656 kJ/d (864 kcal/d); n = 10] or asked to continue their normal eating patterns (n = 9) for one menstrual cycle. Biopsies of the breast and abdominal fat were taken before and after the intervention. RNA was extracted from whole tissues and breast epithelium (by laser capture microdissection) and hybridized to Affymetrix GeneChips. Longitudinal plasma and urine samples were collected before and after intervention, and metabolic profiles were generated using gas chromatography-mass spectrometry. DER was associated with significant reductions in weight [-7.0 (+/-2.3) kg] and in alterations of serum biomarkers of breast cancer risk (insulin, leptin, total and low-density lipoprotein cholesterol, and triglycerides). In both abdominal and breast tissues, as well as isolated breast epithelial cells, genes involved in glycolytic and lipid synthesis pathways (including stearoyl-CoA desaturase, fatty acid desaturase, and aldolase C) were significantly down-regulated. We conclude that reduced expressions of genes in the lipid metabolism and glycolytic pathways are detectable in breast tissue following DER, and these may represent targets for DER mimetics as effective chemoprophylactic agents Transcriptomic and Metabolomic intervention study of continuous energy restriction in 19 participants
Project description:Lymphocyte and breast tissue samples from overweight woman at increased risk of breast cancer before and after 1 month of intermittant energy restriction Introduction Observational studies indicate that weight loss and energy restriction reduce breast cancer risk. Intermittent energy restriction (IER) reduces weight as well as, or more than continuous energy restriction (CER), but its effect on the breast and systemic metabolism as indicators of breast cancer risk are not known. Methods We assessed the effect of IER ( 2 days of 65% energy restriction) for one menstrual cycle on the breast (breast gene expression and fat cell size) and systemic metabolism (insulin resistance, lipids, serum and urine metabolites) in 23 overweight premenopausal women at high risk of breast cancer. Unsupervised hierarchical analysis selected 100 genes with the highest variance between pre and post IER biopsies in 20 subjects, whilst mass spectrometry was used to assess corresponding changes in serum (LCMS) and urine metabolites (GCMS) in 23 subjects in the restricted and unrestricted days of the IER. Results Women lost on average 4.8% (± 2.0) of body weight and 8.0% (± 5.0) of body fat. Insulin resistance (HOMA) was reduced by 29.8% (±17.8) on the restricted days and by 11%(±34) on the unrestricted days of the IER. Over 250 serum and urine metabolites significantly increased or decreased during the two restricted days and most returned to normal after the subsequent five day period . In the breast tissue, approximately half (In 11) of the subjects displayed down regulation of several metabolic pathways including lipid synthesis, growth factors and hormones, whilst epithelial genes including milk proteins, secretoglobulins and mucins were up-regulated and several metabolic pathways down-regulated including lipid synthesis, growth factors and hormones. In the other nine subjects there was no appreciable effect of IER on the breast. CorrespondingThe gene changes were not seen in peripheral blood lymphocytes, and there was no reduction in breast fat cell size. The two groups defined by change in gene expression or lack of it did not differ in the degree of weight or fat loss, other systemic metabolic markers, or histological assessment of the biopsies. Conclusion We conclude that breasts vary in response to short-term IER, the mechanism of which requires further investigation. Trial registration ISRCTN77916487
Project description:Circulating microRNAs (c-miRNAs) have emerged as measurable biomarkers (liquid biopsies) for cancer detection. The goal of our study was to identify novel biomarkers to predict long-term breast cancer risk in cancer-free women. We evaluated the ability of c-miRNAs to identify women most likely to develop breast cancer by profiling miRNA from serum obtained long before diagnosis. 24 breast cancer cases and controls (matched for risk and age) were identified from women enrolled in the High-Risk Breast Program at the UVM Cancer Center. We used Affymetrix miRNA v4 microarrays to interrogate miRNAs (miRBase v20) in the serum of cancer-free women at high-risk for breast cancer. The 24 cases developed breast cancer at least 6 months (average of 3.2 years) and the 24 controls remain cancer-free.
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:Mufudza2012 - Estrogen effect on the dynamics
of breast cancer
This deterministic model shows the
dynamics of breast cancer with immune response. The effects of
estrogen are incorporated to study its effects as a risk factor for
the disease.
This model is described in the article:
Assessing the effects of
estrogen on the dynamics of breast cancer.
Mufudza C, Sorofa W, Chiyaka
ET.
Comput Math Methods Med 2012; 2012:
473572
Abstract:
Worldwide, breast cancer has become the second most common
cancer in women. The disease has currently been named the most
deadly cancer in women but little is known on what causes the
disease. We present the effects of estrogen as a risk factor on
the dynamics of breast cancer. We develop a deterministic
mathematical model showing general dynamics of breast cancer
with immune response. This is a four-population model that
includes tumor cells, host cells, immune cells, and estrogen.
The effects of estrogen are then incorporated in the model. The
results show that the presence of extra estrogen increases the
risk of developing breast cancer.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000642.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:The contralateral unaffected breast of women with unilateral breast cancer (cases) is a good model for defining subtype-specific risk since women with ER-negative index primaries are at high risk for subsequent ER-negative primary cancers. We performed random fine needle aspiration (rFNA) of the unaffected breasts of cases; samples from 30 subjects (15 ER-positive and 15 ER-negative cases matched for age, race and menopausal status), were used for Illumina expression array analysis. In this study, we have examined gene expression profiles in random fine needle aspirate (rFNA) samples from the contralateral breasts of women with new unilateral breast cancer (cases) to seek candidate panels of ER-specific risk biomarkers. On a discovery set of 30 women, we have identified gene expression differences in the contralateral breast that associate with ER+ or ER- index primary tumors.
Project description:Obesity is a risk factor for postmenopausal ERα (+) breast cancer. The metabolites from serum that contribute to this risk and how these factors affect ERα signaling are not known. Using whole metabolite profiling and a detection panel for proteins, we identified biomarkers that were differentially present in serum from obese vs. non-obese postmenopausal women, and we validated these factors in two separate cohorts of postmenopausal women who either developed breast cancer or those who were obese and lost weight after the onset of menopause. In vitro assays identified free fatty acids (FFAs), in particular oleic acid (OA) as serum factors that correlate with increased proliferation and aggressiveness in ERα(+) breast cancer cells by. FFAs activated both ERα and mTOR pathways and rewired metabolism in breast cancer cells. Pathway preferential estrogen-1 (PaPE-1), which target ERα and mTOR signaling, was able to block changes induced by FFAs. In fact, PaPEs were more effective in the presence of FFAs, suggesting a role for obesity-associated gene and metabolic rewiring in providing new targetable vulnerabilities for ERα-(+) breast cancer in postmenopausal women. Our findings provide a basis for preventing or inhibiting obesity-associated breast cancer by using PaPEs that would reverse these newly appreciated metabolic vulnerabilities of breast tumors in obese postmenopausal women.