Rattus norvegicus
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA297423 | ENA |
REPOSITORIES: ENA
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Project description:Human studies suggest that high-fat diets (HFD) increase the risk of breast cancer. The 7,12 dimethylbenz[a]anthracene (DMBA)-induced mammary carcinogenesis rat model is commonly used to evaluate the effects of lifestyle factors such as HFD on mammary-tumor risk. Past studies focused primarily on the effects of continuous maternal exposure on the risk of offspring at the end of puberty (PND50). We assessed the effects of prenatal HFD exposure on cancer susceptibility in prepubertal mammary glands and identified key gene networks associated with such disruption. During pregnancy, dams were fed AIN93G-based diets with high (39% Kcal) olive oil, butterfat, or safflower oil. The control group received AIN-93G with 10% Kcal soy oil. Female offspring were treated with DMBA on PND21. However, a significant increase in tumor volume and a trend of shortened tumor latency were observed in rates with HFD exposure against the controls (p=0.067 and 0.048 respectively). Large-volume tumors harbored carcinoma in situ. Transcriptome profiling identified 43 differentially expressed genes in the mammary glands of the HFD group as compared with control. Rapid hormone signaling was the most dysregulated pathway. The diet also induced aberrant expression of Dnmt3a, Mbd1, and Mbd3, suggesting potential epigenetic disruption. Collectively, these findings provide the first evidence supporting susceptibility of prepubertal mammary glands to DMBA-induced tumorigenesis that can be modulated by dietary fat that involves aberrant gene expression and epigenetic dysregulation.
2015-11-30 | GSE73604 | GEO
Project description:Early postnatal exposures to Bisphenol A (BPA) and genistein (GEN) have been reported to predispose for and against mammary cancer, respectively, in adult rats. Since the changes in cancer susceptibility occurs in the absence of the original chemical exposure, we have investigated the potential of epigenetics to account for these changes. DNA methylation studies reveal that prepubertal BPA exposure alters signaling pathways that contribute to carcinogenesis. Prepubertal exposure to GEN and to BPA + GEN suggests pathways involved in maintenance of cellular function, indicating that the presence of GEN either reduces or counters some of the alterations caused by the carcinogenic properties of BPA. We subsequently evaluated the potential of epigenetic changes in the rat mammary tissues to predict survival in breast cancer patients via The Cancer Genomic Atlas (TCGA). We identified 12 genes that showed strong predictive values for long-term survival in estrogen receptor positive patients. Importantly, two genes associated with improved long term survival, HPSE and RPS9, were identified to be hypomethylated in mammary glands of rats exposed prepuberally to GEN or to GEN + BPA respectively, reinforcing the suggested cancer suppressive properties of GEN.
2017-07-09 | GSE89107 | GEO
Project description:Emerging data indicate that breast epithelial stem cells and progenitors, particularly those in the luminal epithelial cell lineage, are the cells-of-origin of breast carcinomas, and factors that influence breast cancer risk may alter the number and/or properties of these cells. We hypothesize that a subset of p27+ cells represent hormone-responsive progenitors that are quiescent due to the high activity of TGFβ signaling in these cells. The Estrogen-induced mammary tumor model in ACI inbred rats is physiologically relevant rodent model of breast cancer. In the present study we successfully generated Cdkn1b knockout ACI rats and performed comprehensive phenotypic assessment and RNAseq profiling using FACS sorted basal (CD24+CD29high) and luminal (CD24+CD29low) cell populations to characterize Cdkn1b+/+ and Cdkn1b-/- females in prepubertal and adult cohorts. We found that p27KO rats exhibited mammary differentiation phenotype and reduced numbers of mammary epithelial progenitor pool, Interestingly, p27 ablation has the most pronounced effect on luminal progenitor cell gene expression, and milk protein genes and pStat5 were dramatically upregulated, while PR and FoxA1 were greatly downregulated in Cdkn1b-/- luminal cells. Further characterization of mammary glands of prepubertal Cdkn1b knockout rats by fat pad transplantation illustrated p27 deletion in the mammary cancer susceptible ACI rat strain induced mammary epithelial cell differentiation through cell non-autonomous mechanisms.
2019-02-11 | GSE116831 | GEO
Project description:Background: Post-menopausal obesity is an established risk factor for breast cancer. Consumption of diets high in fat is known to be highly correlated with obesity. In this, we sought to evaluate the interaction(s) between high fat diet, weight gain and mammary carcinogenesis using an obese-resistant and obese-prone rat model with direct correlates to human disease. Methods: Female obese-prone (OP) and obese-resistant (OR) weanling rats were placed on either a low fat (10% kcal) or a high fat (39% kcal) n-6 polyunsaturated (PUFA) safflower diet for 30 days. At post natal day (PND) 50, global gene expression profiling was performed on microdissected mammary epithlelium from one cohort of rats and another cohort of rats were given a single oral gavage of either 7,12-dimethylbenz[a]anthracene (DMBA at 14 mg/kg) or vehicle. Rats were then maintained on the diets and body weights, food consumption and development of mammary lesions were monitored weekly. Results: The DMBA-treated OR rats on the 39% safflower diet had significantly greater incidence of ductal carcinoma-in-situ (DCIS) lesions and significantly greater DCIS multiplicity than DMBA-treated OR rats on the 10% safflower diet. These differences were not seen in the OP strain. Gene expression analysis of mammary ductal epithelium from OR rats on the high fat diet showed significant upregulation of proliferation-related genes compared to those consuming the low fat safflower diet. Again, these differences were not seen in the OP strain. Conclusion: Our findings indicate that consumption of high fat safflower diet enhances mammary carcinogenesis in an OR rat strain through increased proliferation of mammary epithelium at the time of exposure, but not in the OP rat strain. Thus, the diet-induced increase in sensitivity was strain-specific and independent of weight gain or obesity level. Female obese-prone (OP) and obese-resistant (OR) weanling rats were placed on either a low fat (10% kcal) or a high fat (39% kcal) n-6 polyunsaturated (PUFA) safflower diet for 30 days. At post natal day (PND) 50, global gene expression profiling was performed on microdissected mammary epithlelium from one cohort of rats and another cohort of rats were given a single oral gavage of either 7,12-dimethylbenz[a]anthracene (DMBA at 14 mg/kg) or vehicle. Rats were then maintained on the diets and body weights, food consumption and development of mammary lesions were monitored weekly.
2010-09-25 | E-GEOD-21150 | biostudies-arrayexpress
Project description:Exposure to common environmental chemicals, including those found in personal care products has been linked to mammary cancer at high doses in animal models. Their effects at low doses at levels comparable to human exposure, especially during critical windows of development remain poorly understood. Using a Sprague-Dawley rat model, we investigated the effects of of three environmental chemicals – diethyl phthalate (DEP), methyl paraben (MPB) and triclosan (TCS) – on the transcriptome of normal developing mammary glands at low doses mimicking human exposure. Rats were exposed during three windows of early development – perinatal (gestation day (GD) 1 - 20 or postnatal day (PND) 1 - 20), prepubertal (PND 21 - 41) and pubertal (PND 42 - 62), as well as chronic exposure from birth to end of lactation (PND 1 - 146). Mammary gland whole-transcriptomes were profiled by Affymetrix rat gene 2.0 st arrays.
2016-10-19 | GSE72276 | GEO
Project description:Background: Post-menopausal obesity is an established risk factor for breast cancer. Consumption of diets high in fat is known to be highly correlated with obesity. In this, we sought to evaluate the interaction(s) between high fat diet, weight gain and mammary carcinogenesis using an obese-resistant and obese-prone rat model with direct correlates to human disease. Methods: Female obese-prone (OP) and obese-resistant (OR) weanling rats were placed on either a low fat (10% kcal) or a high fat (39% kcal) n-6 polyunsaturated (PUFA) safflower diet for 30 days. At post natal day (PND) 50, global gene expression profiling was performed on microdissected mammary epithlelium from one cohort of rats and another cohort of rats were given a single oral gavage of either 7,12-dimethylbenz[a]anthracene (DMBA at 14 mg/kg) or vehicle. Rats were then maintained on the diets and body weights, food consumption and development of mammary lesions were monitored weekly. Results: The DMBA-treated OR rats on the 39% safflower diet had significantly greater incidence of ductal carcinoma-in-situ (DCIS) lesions and significantly greater DCIS multiplicity than DMBA-treated OR rats on the 10% safflower diet. These differences were not seen in the OP strain. Gene expression analysis of mammary ductal epithelium from OR rats on the high fat diet showed significant upregulation of proliferation-related genes compared to those consuming the low fat safflower diet. Again, these differences were not seen in the OP strain. Conclusion: Our findings indicate that consumption of high fat safflower diet enhances mammary carcinogenesis in an OR rat strain through increased proliferation of mammary epithelium at the time of exposure, but not in the OP rat strain. Thus, the diet-induced increase in sensitivity was strain-specific and independent of weight gain or obesity level.
2010-09-25 | GSE21150 | GEO
Project description:Childhood exposure to carcinogens renders a higher risk of breast cancer. The molecular mechanisms underlying cancer development after such exposure are not, however, well understood. Here we examined how the mechanism of cancer development relates to the age at exposure to ionizing radiation (IR) or the carcinogen 1-methyl-1-nitrosourea (MNU). Pre- and postpubertal (3- and 7-week-old, respectively) female Sprague-Dawley rats were whole-body gamma-irradiated (2 Gy), injected intraperitoneally with MNU (20 mg/kg) or left untreated and were autopsied at 50 weeks of age. Mammary carcinomas were examined for estrogen receptor (ER) alpha, progesterone receptor (PR) and ErbB ligand expression and for expression microarrays. Early histological changes of the ovaries were also evaluated. The incidence of mammary cancer was higher after postpubertal, rather than prepubertal, IR exposure; the inverse was true for MNU. Most cancers were positive for both ER alpha and PR except for the prepubertal IR group. Interestingly, cancers of the prepubertal IR group expressed a different set of ErbB ligands from those of the other groups and did not overexpress Areg, which encodes an estrogen-regulated ErbB ligand, or other developmentally related genes including those for hormonally regulated mammary gland development. Prepubertal IR exposure resulted in ovarian dysfunction as revealed by a reduced follicular pool. Evidence thus suggests that mammary carcinogenesis induced by prepubertal IR exposure is independent of ovarian hormones but requires certain ErbB ligands; induction by postpubertal exposure depends on ovarian hormones and different ErbB ligands. In contrast, MNU-induced carcinogenesis was less influenced by the age at exposure.
2011-01-19 | GSE22770 | GEO
Project description:Sperm cells from Sprague Dawley male rats fed different high fat diets (lard or corn oil based) and their 50-days-old female offspring mammary gland were used to perfom this array
2016-01-21 | GSE77012 | GEO
Project description:We are using ACI and BN rats, which differ markedly in their susceptibility to 17beta-Estradiol (E2)-induced mammary cancer, to identify genetic variants and environmental factors that determine mammary cancer susceptibility. The objective of this study was to characterize the cellular and molecular responses to E2 in the mammary glands of ACI and BN rats to identify qualitative and quantitative phenotypes that associate with and/or may confer differences in susceptibility to mammary cancer. Female ACI and BN rats were treated with E2 for 1, 3 or 12 weeks and cell proliferation, apoptosis, differentiation and gene expression were evaluated. The luminal epithelium of ACI rats exhibited a rapid and sustained proliferative response to E2. By contrast, the proliferative response exhibited by the mammary epithelium of BN rats was restrained and transitory. Moreover, the epithelium of BN rats appeared to undergo differentiation in response to E2, as evidenced by production of milk proteins as well as luminal ectasia and associated changes in the extracellular matrix (ECM). Marked differences in expression of genes that encode proteins with well-defined roles in mammary gland development (Pgr, Wnt4, Tnfsf11, Prlr, Stat5a, Areg, Gata3), differentiation and milk production (Lcn2, Spp1), regulation of extracellular environment (Mmp7, Mmp9), and cell-cell or cell-ECM interactions (Cd44, Cd24, Cd52) were observed. We propose that these cellular and molecular phenotypes are heritable and may underlie, at least in part, the differences in mammary cancer susceptibility exhibited by ACI and BN rats. Two groups of 17beta-estradiol treated female rats were compared. Five ACI and five BN rats were treated with 17beta-estradiol for 12 weeks. Total RNA was isolated from the mammary glands of these animals, labeled, and hybridized to Affymetrix Rat Genome 230 2.0 Arrays (Affymetrix Inc.). Significantly differentially expressed genes were found between these groups.
2014-02-01 | E-GEOD-49548 | biostudies-arrayexpress
Project description:The linkage between nutrition and cancer prevention is an intriguing concept that is gaining widespread support based on epidemiological and animal studies. Multiple mechanisms likely underlie dietary protection against cancer, with effects influenced by target tissue response, cell-cell interactions and developmental context. Given the negative correlation between breast cancer incidence and intake of soy foods by Asian women, and the increasing consumption of soy protein-based formula by infants in the Western world, we have studied soy protein isolate (SPI) used in most infant formula as a paradigm to evaluate diet as a risk factor in a rodent model of mammary cancer. We previously demonstrated that lifetime exposure to dietary SPI reduced the incidence of N-methyl-N-nitrosourea-induced mammary tumors in young adult rats relative to those fed the control diet Casein (CAS). This protection was associated with increased tumor suppressor PTEN and decreased Wnt signaling component expression in mammary epithelial cells at postnatal day (PND) 50 prior to carcinogen insult. To identify early events contributing to mammary tumor suppression by diet, we used Affymetrix RAE230A GeneChips containing 14280 probe sets and the GeneSpring Robust Multi-array program to analyze genomic profiles of mammary glands of prepubertal (PND21) rats lifetime exposed to SPI or CAS. Experiment Overall Design: Female SD rats are exposed to either casein/soy protein isolate based AIN-93G diet since gestation day 4 till weaning. Whole mammary gland were harvested for the gene analysis by microarray.
2009-08-07 | E-GEOD-12217 | biostudies-arrayexpress