Ontology highlight
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PROVIDER: PRJNA504606 | ENA |
REPOSITORIES: ENA
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Project description:BACKGROUND: The NF1 tumor suppressor gene is the main negative regulator of the RAS pathway and is frequently mutated in various cancers. Women with Neurofibromatosis Type I (NF1) – a tumor predisposition syndrome caused by a germline NF1 mutation – have an increased risk of developing aggressive breast cancer with poorer prognosis. The mechanisms by which NF1 mutation leads to breast cancer tumorigenesis are not well understood. Therefore, the objective of this work was to identify stromal alterations before tumor formation that result in the increased risk and poorer outcome seen among NF1 patients with breast cancer. METHODS: To accurately model the germline monoallelic NF1 mutations in NF1 patients, we utilized an Nf1-deficient rat model with accelerated mammary development and develops highly penetrant breast cancer. RESULTS: We identified increased collagen content in Nf1-deficient rat mammary glands before tumor formation that correlated with age of tumor onset. Additionally, gene expression analysis revealed that Nf1-deficient rat mammary mature adipocytes have increased collagen expression and shifted to a fibroblast and preadipocyte expression profile. This alteration in lineage commitment was also observed with in vitro differentiation but flow cytometry analysis did not show a change mammary adipose-derived mesenchymal stem cell abundance. CONCLUSION: Collectively, these studies uncovered the previously undescribed role of Nf1 in mammary collagen deposition and regulating adipocyte differentiation. In addition to unraveling the mechanism of tumor formation, further investigation of adipocytes and collagen modifications in preneoplastic mammary gland will create a foundation for developing early detection strategies of breast cancer among NF1 patients.
2023-05-08 | GSE231603 | GEO
Project description:Rat mammary tumors induced by N-methyl-N-nitrosurea (NMU) and normal mammary gland Keywords = breast cancer Keywords = rat mammary tumor Keywords = NMU Keywords = animal model. Keywords: other
2005-04-30 | GSE1872 | GEO
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:The role of diet in the prevention of breast cancer is widely accepted, yet little is known on how early dietary effects mitigate adult cancer risk. Soy consumption is associated with reduced breast cancer risk in women, an effect largely attributed to the soy isoflavone genistein (GEN). We previously showed lower chemically-induced mammary tumor incidence in young adult rats with lifetime dietary intake of soy protein isolate (SPI), a highly refined soy product in infant formula, than in those fed the control diet Casein (CAS). To gain insight into signaling pathways underlying dietary tumor protection, we performed genome-wide expression profiling of mammary epithelial cells from young adult rats lifetime fed CAS, SPI, or supplemental GEN-based diets. We identified mammary epithelial genes regulated by SPI (79 total) and GEN (99 total) using Affymetrix rat 230A GeneChip arrays and found minimal overlap in gene expression patterns. We showed that the regulated transcripts functionally cluster in biochemical pathways involving metabolism, immune response, signal transduction, and ion transport. We confirmed the differential expression of Wnt (Wnt5a, Sfrp2) and Notch (Notch2, Hes1) signaling components by SPI and/or GEN using QPCR. Wnt pathway inhibition by GEN was supported by lower Cyclin D1 immunoreactivity in mammary ductal epithelium of GEN relative to CAS and SPI, despite their comparable levels of membrane-localized E-cadherin and β-catenin. Identification of distinct GEN and SPI responsive genes in mammary epithelial cells may define early events contributing to tumor protection by diet relevant to the prevention of breast and other types of cancer. Experiment Overall Design: Female Sprague-Dawley rats, fed one of the three purified diets, were studied at postnatal day50. Total RNA( each RNA samples were extracted from #4 mammary gland from two animals under the same diet group) purified from non-tumor tissue within the proximal half of each colon, was used to prepare biotinylated probes, which were hybridized to Affymetrix RAE230 rat microarrays.
2007-11-29 | E-GEOD-6879 | biostudies-arrayexpress
Project description:Maternal exposures during pregnancy influence the risk of many chronic adult-onset diseases in the offspring. We investigated whether feeding pregnant rats a high fat (HF) or ethinyl-estradiol (EE2)-supplemented diet affects carcinogen-induced mammary cancer risk in daughters, granddaughters and great-granddaughters. Here we show that mammary tumorigenesis is higher in daughters and granddaughters of HF rat dams and in daughters, granddaughters and great-granddaughters of EE2 rat dams. Outcross experiments indicate that increased mammary cancer risk is transmitted to HF granddaughters equally through the female or male germlines, but it is only transmitted to EE2 granddaughters through the female germline. The effects of maternal EE2 exposure on offspring's mammary cancer risk are associated with alternations in the DNA methylation machinery and methylation patterns in mammary tissue of all three EE2 generations. We conclude that dietary and estrogenic exposures in pregnancy increase breast cancer risk in multiple generations of offspring, possibly through non-genetic means
2012-09-20 | GSE40251 | GEO
Project description:Maternal exposures during pregnancy influence the risk of many chronic adult-onset diseases in the offspring. We investigated whether feeding pregnant rats a high fat (HF) or ethinyl-estradiol (EE2)-supplemented diet affects carcinogen-induced mammary cancer risk in daughters, granddaughters and great-granddaughters. Here we show that mammary tumorigenesis is higher in daughters and granddaughters of HF rat dams and in daughters, granddaughters and great-granddaughters of EE2 rat dams. Outcross experiments indicate that increased mammary cancer risk is transmitted to HF granddaughters equally through the female or male germlines, but it is only transmitted to EE2 granddaughters through the female germline. The effects of maternal EE2 exposure on offspring's mammary cancer risk are associated with alternations in the DNA methylation machinery and methylation patterns in mammary tissue of all three EE2 generations. We conclude that dietary and estrogenic exposures in pregnancy increase breast cancer risk in multiple generations of offspring, possibly through non-genetic means We examined the whole genome methylation status of both control and EE2-supplemented diet rats in three consecutive generations
2012-09-20 | E-GEOD-40251 | biostudies-arrayexpress
Project description:Cancer risk by environmental exposure is modulated by an individual’s genetics and age at exposure. This age-specific period of susceptibility is referred to as a “Window of Susceptibility” (WOS). Radiation exposures poses a high breast cancer risk for women between the early childhood and young adult stage and is reduced in the mid-30s. Rats have a similar WOS for developing breast cancer. Previous studies have identified a looping interaction between a genomic region in the mammary carcinoma susceptibility Mcs5c locus and a known cancer gene, PAPPA. However, the global role of three-dimensional organization in the WOS is not known. Therefore, we generated Hi-C and RNA-seq data in rat mammary epithelial cells within and outside WOS. We compared the temporal changes in chromosomal looping to those in expression and find that interactions that have significantly higher counts within WOS are significantly enriched for genes upregulated in WOS. To systematically identify higher-order changes in 3D genome organization, we developed an approach that combines network enhancement to smooth the Hi-C matrices followed by multitask non-negative matrix factorization (NMF) to identify clusters of interacting loci. We found that large-scale topological re-organizations are enriched for differential interactions within and outside the WOS timepoints. Finally, we mapped previously published breast-cancer associated human GWAS variants to rat loci and identified the corresponding rat ortholog gene interacting with the loci. Many of the associated rat genes participate in differential interactions, recapitulate the human SNP- gene interactions and are associated with breast cancer. Our results suggest that WOS-specific changes in 3D genome organization are linked to transcriptional changes that may increase susceptibility to breast cancer.
2022-01-11 | GSE184284 | GEO
Project description:Cancer risk by environmental exposure is modulated by an individual’s genetics and age at exposure. This age-specific period of susceptibility is referred to as a “Window of Susceptibility” (WOS). Radiation exposures poses a high breast cancer risk for women between the early childhood and young adult stage and is reduced in the mid-30s. Rats have a similar WOS for developing breast cancer. Previous studies have identified a looping interaction between a genomic region in the mammary carcinoma susceptibility Mcs5c locus and a known cancer gene, PAPPA. However, the global role of three-dimensional organization in the WOS is not known. Therefore, we generated Hi-C and RNA-seq data in rat mammary epithelial cells within and outside WOS. We compared the temporal changes in chromosomal looping to those in expression and find that interactions that have significantly higher counts within WOS are significantly enriched for genes upregulated in WOS. To systematically identify higher-order changes in 3D genome organization, we developed an approach that combines network enhancement to smooth the Hi-C matrices followed by multitask non-negative matrix factorization (NMF) to identify clusters of interacting loci. We found that large-scale topological re-organizations are enriched for differential interactions within and outside the WOS timepoints. Finally, we mapped previously published breast-cancer associated human GWAS variants to rat loci and identified the corresponding rat ortholog gene interacting with the loci. Many of the associated rat genes participate in differential interactions, recapitulate the human SNP- gene interactions and are associated with breast cancer. Our results suggest that WOS-specific changes in 3D genome organization are linked to transcriptional changes that may increase susceptibility to breast cancer.
2022-01-11 | GSE184280 | GEO
Project description:<p>DNA Inverted Repeats as an At-risk Motif for Palindromic Gene Amplificatio defines oncogene amplification that is configured as a series of inverted duplications (palindromic gene amplification). There are several, recurrently amplified oncogenes throughout the human genome. However, it remains unclear whether this recurrent amplification is solely a manifestation of increased fitness resulting from random amplification mechanisms, or if genomic locus-specific amplification mechanism plays a role. </p> <p>In this study, we show that the ERBB2 oncogene at 17q12 is susceptible to palindromic gene amplification in HER2-positive breast tumors. We investigated eight tumors in this study, of which five tumors were HER2-positive, and three tumors were HER2-negative. HER2-status was determined by clinical FISH tests. We applied three genomic approaches to investigate the amplification mechanism: (1) copy number analysis by array-CGH on the Affymetrix SNP6.0 platform (8 files), (2) sequencing of DNA libraries enriched with tumor-derived palindromic DNA (Genome-wide Analysis of Palindrome Formation, GAPF-seq) (8 files) and (3) unbiased whole genome sequencing (WGS) (1 file). These molecular data is made available in the dbGaP. </p> <p>Genomic studies using tumor DNA was approved under the Internal Institutional Review Board at the Cleveland Clinic (IRB07-136: EXEMPT: Chromosome Breakage and DNA Palindrome Formation). Specimens were obtained and methods were carried out under the auspices of IRB 7881 (Evaluation of Genetic and Molecular Markers in Patients with Breast Cancer). All patients consented to allow their cancer specimens to be used by researchers in an anonymized fashion. The consent form indicates that publication will take place without identifiers to protect the identity of any specific individual.</p> <p>We observed significant and enrichment of palindromic DNA within amplified ERBB2 genomic segments in four out of five HER2-positive tumors. None of three HER2-negative tumors showed such enrichment. Palindromic DNA was particularly enriched at amplification peaks and boundaries between amplified and normal copy-number regions. Thus, palindromic gene amplification shaped the amplified ERBB2 locus. The moderate enrichment of palindromic DNA throughout the amplified segments leads us to propose that the ERBB2 locus is amplified through a mechanism that repeatedly generates palindromic DNA, such as Breakage-Fusion-Bridge cycles. Our results reveal a potential interaction between local genomic environments and gene amplification mechanisms. </p> <p>This study is published under the title "Palindromic amplification of the ERBB2 oncogene in primary HER2-positive breast tumors" <a href="https://www.ncbi.nlm.nih.gov/pubmed/?term=28211519" target="_blank">(PMID:28211519)</a>. </p>
| phs001261 | dbGaP