Genome wide DNA methylation profiling of normal breast, normal adjacent and breast cancer tissue
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE69914 | GEO | 2015/06/18
SECONDARY ACCESSION(S): PRJNA287264
REPOSITORIES: GEO
Similar Datasets
Project description:The Illumina Infinium 450k Human DNA methylation Beadchip was used to obtain DNA methylation profiles across approximately 480,000 CpGs in a total of 407 samples, including 50 normal samples from healthy women, 42 matched normal-adjacent breast cancer pairs (84 samples), 263 unmatched breast cancers, 7 normal samples from BRCA1 carriers and 4 BRCA1 breast cancers. Bisulphite converted DNA from the 407 samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip
2015-06-18 | E-GEOD-69914 | biostudies-arrayexpress
Project description:Gene expression profiles of normal human mammary tissue from BRCA1 mutation carriers, non-BRCA1/2 mutation carriers and normal women. RNA was prepared from normal breast tissue (confirmed by pathology) from reduction mammoplasties (n=5) and prophylactic mastectomies of known BRCA1 (n=7) and non-BRCA1/2 mutation carriers (n=8). non-BRCA1/2 carriers were individuals with a strong family history of breast cancer (kConFab Category 1 (http://www.kconfab.org/Collection/Eligibility.shtml) where no mutation in BRCA1 or BRCA2 has been identified in the family by high sensitivity testing (http://www.kconfab.org/Progress/Sensitivity.shtml) of any individual affected by breast or ovarian cancer. Normal breast samples refer to reduction mammoplasty specimens, where family history is generally not known.
2009-08-01 | GSE17072 | GEO
Project description:Breast cancer and normal breast tissue samples to estimate the effect of contamination of breast cancer samples with normal breast tissue
| PRJNA512930 | ENA
Project description:Gene expression profiles of normal human mammary tissue from BRCA1 mutation carriers, non-BRCA1/2 mutation carriers and normal women. RNA was prepared from normal breast tissue (confirmed by pathology) from reduction mammoplasties (n=5) and prophylactic mastectomies of known BRCA1 (n=7) and non-BRCA1/2 mutation carriers (n=8). non-BRCA1/2 carriers were individuals with a strong family history of breast cancer (kConFab Category 1 (http://www.kconfab.org/Collection/Eligibility.shtml) where no mutation in BRCA1 or BRCA2 has been identified in the family by high sensitivity testing (http://www.kconfab.org/Progress/Sensitivity.shtml) of any individual affected by breast or ovarian cancer. Normal breast samples refer to reduction mammoplasty specimens, where family history is generally not known. Microarray expression profiles were obtained from whole pre-neoplastic breast tissue from three categories of patient, as described in the summary. Samples were checked for keratin gene expression levels as a marker for epithelium tissue, and a number of samples were removed because two or more keratin genes lacked detectable expression (BeadStudio detection p-value 0.01). One other sample was removed because its expression profile appeared abnormal. Out of 36 samples initially profiled, 20 passed the quality filters and were used for the final analysis.
2009-08-01 | E-GEOD-17072 | biostudies-arrayexpress
Project description:Background: Normal cell BRCA1 epimutations have been associated with increased risk of triple-negative breast cancer (TNBC). However, the fraction of TNBCs that may have BRCA1 epimutations as their underlying cause is unknown. Neither are the time of occurrence and the potential inheritance patterns of BRCA1 epimutations established. Methods: To address these questions, we analyzed BRCA1 methylation status in breast cancer tissue and matched white blood cells (WBC) from 408 patients with 411 primary breast cancers, including 66 TNBCs, applying a highly sensitive sequencing assay, allowing allele-resolved methylation assessment. Further, to assess the time of origin and the characteristics of normal cell BRCA1 methylation, we analyzed umbilical cord blood of 1260 newborn girls and 200 newborn boys. Finally, we assessed BRCA1 methylation status among 575 mothers and 531 fathers of girls with (n = 102) and without (n = 473) BRCA1 methylation. Results: We found concordant tumor and mosaic WBC BRCA1 epimutations in 10 out of 66 patients with TNBC and in four out of six patients with estrogen receptor (ER)-low expression (<10%) tumors (combined: 14 out of 72; 19.4%; 95% CI 11.1–30.5). In contrast, we found concordance in only three out of 220 patients with 221 ER≥10% tumors and zero out of 114 patients with 116 HER2-positive tumors. Intraindividually, BRCA1 epimutations affected the same allele in normal and tumor cells. Assessing BRCA1 methylation in umbilical WBCs from girls, we found mosaic, predominantly monoallelic BRCA1 epimutations, with qualitative features similar to those in adults, in 113/1260 (9.0%) of individuals, but no correlation to BRCA1 methylation status either in mothers or fathers. A significantly lower fraction of newborn boys carried BRCA1 methylation (9 / 200; 4.5%) as compared to girls (p = 0.038). Similarly, WBC BRCA1 methylation was found less common among fathers (16/531; 3.0%), as compared to mothers (46 / 575; 8.0%; p = 0.0003). Conclusions: Our findings suggest prenatal BRCA1 epimutations might be the underlying cause of around 20% of TNBC and low-ER expression breast cancers. Such constitutional mosaic BRCA1 methylation likely arise through gender-related mechanisms in utero, independent of Mendelian inheritance.
2023-10-26 | GSE243956 | GEO
Project description:bulk breast tumor RNA from patient; Abstract: Sporadic basal-like cancers (BLC) are a distinct class of human breast cancers that are phenotypically similar to BRCA1-associated cancers. Like BRCA1-deficient tumors, most BLC lack markers of a normal inactive X chromosome (Xi). Duplication of the active X chromosome and loss of Xi characterized almost half of BLC cases tested. Others contained biparental but nonheterochromatinized X chromosomes or gains of X chromosomal DNA. These abnormalities did not lead to a global increase in X chromosome transcription but were associated with overexpression of a small subset of X chromosomal genes. Other, equally aneuploid, but non-BLC rarely displayed these X chromosome abnormalities. These results suggest that X chromosome abnormalities contribute to the pathogenesis of BLC, both inherited and sporadic. total 62 sample incudes 43 tumor, 7 normal breast and 12 normal organelle Experiment Overall Design: compare expression of tumor to normal breast tissue
2008-06-16 | E-GEOD-7904 | biostudies-arrayexpress
Project description:This study presents a single cell transcriptome map of nearly 430,000 cells encompassing normal breast at different hormonal stages, preneoplastic BRCA1+/- tissue, the major clinical subtypes of breast cancer, and matching pairs of tumors and involved axillary lymph nodes. Comparison of normal tissue specimens according to menopausal status primarily revealed changes in the stroma. Although there were modest changes in the microenvironment of preneoplastic BRCA1+/- versus normal tissue, a profound increase in infiltrating immune cells and a concomitant decrease in fibroblasts accompanied the transition to neoplasia. Single cell profiling of 32 tumors representing treatment-naive ER+, HER2+, triple negative (TN) breast cancers revealed equivalent diversity between tumor cells across the subtypes, each comprising a broad cluster and a prominent subset of cycling cells. In the immune landscape of tumors, highly proliferative T cells characterize TN and HER2+ tumors, whereas cycling tumor-associated macrophages featured in ER+ tumors. Copy number variant and scRNA-seq analysis of paired ER+ tumors and lymph node (LN) samples revealed either collective migration of primary tumor cells into LNs or seeding by genetically distinct clones. This large-scale integration of patient samples provides a high resolution map of cell diversity for normal and cancerous human breast.
2021-03-19 | GSE161529 | GEO
Project description:PURPOSE: To estimate the effect of contamination with normal breast tissue for the development of gene signatures robust to pre-analytical conditions. METHODS: We evaluated the effect of contamination with normal breast tissue on gene signatures by comparing microarray profiles of breast cancer samples contaminated with increasing amounts of normal breast tissue.
2019-05-30 | GSE124646 | GEO
Project description:Early genetic changes during cancer initiation may provide targets for agents that delay, or even prevent, cancer. We hypothesized that cells bearing a single inherited âhitâ in a tumor suppressor gene express an altered mRNA repertoire that may identify targets for measures that could delay or even prevent progression to carcinoma. Here, we report on the transcriptomes of primary breast and ovarian epithelial cells cultured from BRCA1 and BRCA2 mutation-carriers and controls. Our comparison analyses identified multiple changes in gene expression, in both tissues for both mutations that were independently validated by real-time RT-PCR analysis. Several of the differentially expressed genes had been previously proposed as cancer markers including, mammaglobin in breast cancer and serum amyloid in ovarian cancer. These findings demonstrate that heterozygosity for a mutant tumor suppressor gene can alter the expression profiles of phenotypically normal epithelial cells in a gene-specific manner, and that these detectable effects of âone-hitâ represent early molecular changes in tumorigenesis that may serve as novel biomarkers of cancer risk and as targets for chemoprevention Using affymetrix U133 plus2 chips, we compare the transcriptome of primary breast and ovarian epithelial cultures derived from subjects predisposed to cancer, bearing monoallelic BRCA1 or BRCA2 mutations, with corresponding cultures from control individuals that do not have mutations. For both breast and ovarian samples, epithelial cell cultures were generated from 6 subjects that have both BRCA1 or BRCA2 mutations and 6 subjects that do not have mutations. Affymetrix U133 plus 2 chips were used to profile the transcriptome of BRCA1 or BRCA2 mutant and wild type. In total 36 chips were used to profile 18 samples from both breast and ovary, 6 mutant (BRCA1 and BRCA2) and 6 wild type.
2010-03-07 | E-GEOD-19383 | biostudies-arrayexpress
Project description:The purpose of this study was to understand the genomic and metabolomic changes in the breast tissue microenvironment at various stages of cancer development and progression (i.e. normal breast, DCIS, benign disease and invasive cancer). To understand the way in which metabolic microenvironments evolve with breast cancer, this study analyzed normal breast tissue adjacent to benign and malignant lesions at various stages of cancer development and studied samples adjacent to invasive cancers of distinct breast cancer subtypes.
| ST000053 | MetabolomicsWorkbench