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: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:Obesity, a major risk factor for chronic diseases, is related to dsyfunctional adipose tissue signaling. First human trials suggest benefits of intermittent calorie restriction diet (ICR) in chronic disease prevention that may exceed those of continuous calorie restriction diet (CCR), even at equal net calorie intake. The effect of intermittent calorie restriction on adipose tissue signaling has not been investigated to date. Thus we initiated a randomized controlled trial to analyze the effect of ICR (eu-caloric diet on five days and two days per week with energy restriction of 75%), CCR (daily energy restriction of 20%) and a control group on subcutaneous adipose tissue (SAT) gene expression. 150 overweight or obese non-smoking adults (50 per group, 50% women) were randomly asiged to one of the study arms. SAT biopsies were taken before and after the 12 week intervention phase.
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: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:Activation of inflammatory pathways is one plausible mechanism underlying the association between obesity and increased breast cancer risk. However, macrophage infiltration and local biomarkers of inflammation in breast adipose tissue have seldom been studied in association with obesity. Gene expression profiles of normal breast tissue from reduction mammoplasty patients were evaluated by whole genome microarrays to identify patterns associated with obesity status (normal-weight, body mass index (BMI) <25; overweight, BMI 25-29.9; obese, BMI > or equal to 30). The presence of macrophage-enriched inflammatory loci with immunopositivity for CD68 protein was evaluated by immunohistochemistry (IHC). After adjusting for confounding by age, 760 genes were differentially expressed (203 up and 557 down; FDR = 0.026) between normal-weight and obese women. Gene ontology analysis suggested significant enrichment for pathways involving IL-6, IL-8, CCR5 signaling in macrophages and RXRalpha and PPARalpha activation, consistent with a pro-inflammatory state and suggestive of macrophage infiltration. Gene set enrichment analysis also demonstrated that the genomic signatures of monocytes and macrophages were over-represented in the obese group with FDR of 0.08 and 0.13, respectively. Increased macrophage infiltration was confirmed by IHC, which showed that the breast adipose tissue of obese women had higher average macrophage counts (mean = 8.96 vs. 3.56 in normal-weight women) and inflammatory foci counts (mean = 4.91 vs. 2.67 in normal-weight women). Obesity is associated with local inflammation and macrophage infiltration in normal human breast adipose tissues. Given the role of macrophages in carcinogenesis, these findings have important implications for breast cancer etiology and progression. 72 normal breast tissue samples from patients undergoing reduction mammoplasty. Reference design.
Project description:Breast adipose tissue is an important contributor to the obesity-breast cancer link. Dysregulated cell metabolism is now an accepted hallmark of cancer. Extracellular vesicles (EVs) are nanosized particles containing selective cargo, such as miRNAs, that act locally or circulate to distant sites to modulate target cell functions. Here, we found that long-term education of breast cancer cells (MCF7, T47D) with EVs obtained from breast adipose tissue of women who are overweight or obese (O-EVs) leads to sustained increased proliferative potential. RNA-Seq of O-EV-educated MCF7 cells demonstrates increased expression of genes, such as ATP synthase and NADH: ubiquinone oxidoreductase, involved in oxidative phosphorylation.
Project description:Detection of breast cancer (BC) in young women is challenging because mammography, the most common tool for detecting BC, is not effective on the dense breast tissue characteristic of young women. In addition to the limited means for detecting their BC, young women face a transient increased risk of pregnancy-associated BC. As a consequence, reproductively active women could benefit significantly from a tool that provides them with accurate risk assessment and early detection of BC. One potential method for detection of BC is biochemical monitoring of proteins and other molecules in bodily fluids such as serum, nipple aspirate, ductal lavage, tear, urine, saliva and breast milk. Of all these fluids, only breast milk provides access to a large volume of breast tissue, in the form of exfoliated epithelial cells, and to the local breast environment, in the form of molecules in the milk. Thus, analysis of breast milk is a non-invasive method with significant potential for assessing BC risk. Here we analyzed human breast milk by mass spectrometry (MS)-based proteomics to build a biomarker signature for early detection of BC. Ten milk samples from 8 women provided 5 paired-groups (cancer versus control) for analysis of differentially expressed proteins: 2 within woman comparisons (milk from a diseased breast versus a healthy breast of the same woman) and 3 across women comparisons (milk from a woman with cancer versus a woman without cancer). Despite a wide range in the time between milk donation and cancer diagnosis (cancer diagnosis occurred from 1 month before to 24 months after milk donation), the levels of some proteins differed significantly between cancer and control in several of the 5 comparison groups. These pilot data are supportive of the idea that molecular analysis of breast milk will identify proteins informative for early detection and accurate assessment of BC risk, and warrant further research.