Transcription profiling by array of histologically-normal human breast tissue
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Chen DT
PROVIDER: S-ECPF-GEOD-10780 | biostudies-other | 2010 Jan
REPOSITORIES: biostudies-other
Similar Datasets
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
| S-ECPF-GEOD-7904 | biostudies-other
Project description:Brain metastasis is one of the most feared complications of cancer and the most common intracranial malignancy in adults. Its underlying mechanisms remain unknown. From breast cancer patients with metastatic disease we isolated cell populations that aggressively colonize the brain. Transcriptomic analysis of these cells yielded overlapping gene sets whose expression is selectively associated with brain metastasis. The expression of seventeen of these genes in primary breast tumors is associated with brain relapse in breast cancer patients. Some of these genes are also associated with metastasis to lung but not to liver, bone or lymph nodes, providing a molecular basis for the long-observed link between brain and lung metastasis. Among the functionally validated brain metastasis genes, the cyclooxigenase COX-2, the EGFR ligand HB-EGF, and the brain-specific 2-6 sialyltransferase ST6GALNAC5 mediate cancer cell passage through the blood-brain barrier. Other brain metastasis genes encode inflammatory factors and brain-specific proteolytic regulators, suggesting a multifaceted program for breast cancer colonization of the brain. Experiment Overall Design: 204 primary tumors from breast cancer patients with known site of relapse were studied, focussing on brain relapse versus other relapse. Identified genes were validated in this cohort.
| S-ECPF-GEOD-12276 | biostudies-other
Project description:Several studies have sought to identify novel transcriptional biomarkers in normal breast or breast microenvironment to predict tumor risk and prognosis. However, systematic efforts to evaluate intra-individual variability of gene expression within normal breast have not been reported. This study analyzed the microarray gene expression data of 288 samples from 170 women in the Normal Breast Study (NBS), wherein multiple histologically normal breast samples were collected from different block regions and different sections at a given region. Intra-individual differences in global gene expression and selected gene expression signatures were quantified and evaluated in association with other patient-level factors. We found that intra-individual reliability was relatively high in global gene expression, but differed by signatures, with composition-related signatures (i.e., stroma) having higher intra-individual variability and tumorigenesis-related signatures (i.e., proliferation) having lower intra-individual variability. Histological stroma composition was the only factor significantly associated with heterogeneous breast tissue (defined as > median intra-individual variation; high nuclear density, odds ratio [OR] = 3.42, 95% confidence interval [CI] = 1.15-10.15; low area, OR = 0.29, 95% CI = 0.10-0.86). Other factors suggestively influencing the variability included age, BMI, and adipose nuclear density. Our results underscore the importance of considering intra-individual variability in tissue-based biomarker development, and have important implications for normal breast research.
| S-EPMC6002361 | biostudies-literature
Project description:Breast carcinogenesis is a multistep process accompanied by widespread molecular and genomic alterations, both in tumor and in surrounding microenvironment. It is known that tumors have altered metabolism, but the metabolic changes in normal or cancer-adjacent, nonmalignant normal tissues and how these changes relate to alterations in gene expression and histological composition are not well understood. Normal or cancer-adjacent normal breast tissues from 99 women of the Normal Breast Study (NBS) were evaluated. Data of metabolomics, gene expression and histological composition was collected by mass spectrometry, whole genome microarray, and digital image, respectively. Unsupervised clustering analysis determined metabolomics-derived subtypes. Their association with genomic and histological features, as well as other breast cancer risk factors, genomic and histological features were evaluated using logistic regression. Unsupervised clustering of metabolites resulted in two main clusters. The metabolite differences between the two clusters suggested enrichment of pathways involved in lipid metabolism, cell growth and proliferation, and migration. Compared with Cluster 1, subjects in Cluster 2 were more likely to be obese (body mass index ≥30 kg/m2, p<0.05), have increased adipose proportion (p<0.01) and associated with a previously defined Active genomic subtype (p<0.01). By the integrated analyses of histological, metabolomics and transcriptional data, we characterized two distinct subtypes of non-malignant breast tissue. Further research is needed to validate our findings, and understand the potential role of these alternations in breast cancer initiation, progression and recurrence.
| S-EPMC5905995 | biostudies-literature
Project description:Historical data have indicated the potential for the histologically-normal breast to harbor pre-malignant changes at the molecular level. We postulated that a histologically-normal tissue with "tumor-like" gene expression pattern might harbor substantial risk for future cancer development. Genes associated with these high-risk tissues were considered to be "malignancy-risk genes". From a total of 90 breast cancer patients, we collected a set of 143 histologically-normal breast tissues derived from patients harboring breast cancer who underwent curative mastectomy, as well as a set of 42 invasive ductal carcinomas (IDC) of various histologic grades. All samples were assessed for global gene expression differences using microarray analysis. For the purpose of this study we defined normal breast tissue to include histologically normal and benign lesions. Here we report the discovery of a "malignancy-risk" gene signature that may portend risk of breast cancer development in benign, but molecularly-abnormal, breast tissue. Pathway analysis showed that the malignancy-risk signature had a dramatic enrichment for genes with proliferative function, but appears to be independent of ER, PR, and HER2 status. The signature was validated by RT-PCR, with a high correlation (Pearson correlation = 0.95 with P < 0.0001) with microarray data. These results suggest a predictive role for the malignancy-risk signature in normal breast tissue. Proliferative biology dominates the earliest stages of tumor development.
| S-EPMC2796276 | biostudies-literature
Project description:Comparisons among breast cancer metastases at different organs revealed distinct microenvironments as characterized by cytokine content. Such microenvironment distinction might be important to dictate how the cancer cells adapt to survival before they successfully colonize. Experiment Overall Design: 58 breast cancer metastases from different organs were profiled and compared by the expression level of over 400 cytokines. 29 samples were incuded in this series. 29 others as well as 7 in the present series were profiled on U133A platforms and included in series GSE14018.
| S-ECPF-GEOD-14017 | biostudies-other
Project description: Not available
| S-ECPF-TABM-657 | biostudies-other
Project description:The molecular basis of breast cancer invasion and metastasis is not well understood. Our objective was to analyze transcriptome differences between stromal and epithelial cells in normal breast tissue and invasive breast cancer to define the role stroma plays in invasion. Total RNA was isolated from epithelial and stromal cells that were laser captured from normal breast tissue (n=5) and invasive breast cancer (n=28). Gene expression was measured using Affymetrix U133A 2.0 GeneChips. Differential gene expression was evaluated and compared within a model that accounted for cell type (epithelial [E] versus stromal [S]), diagnosis (cancer [C] versus normal [N]) as well as cell type-diagnosis interactions. Compared to NE, the CE transcriptome was highly enriched with genes in proliferative, motility and ECM ontologies. Differences in CS and NS transcriptomes suggested that the ECM was being remodeled in invasive breast cancer, as genes were over-represented in ECM and proteolysis ontologies. Genes more highly expressed in CS compared to CE were primarily ECM components or were involved in the remodeling of ECM, suggesting that ECM biosynthesis and remodeling were initiated in the tumor stromal compartment. Experiment Overall Design: Breast tissue was collected at surgery from patients undergoing surgical resection for invasive breast cancer (n=28) and reduction mammoplasty (n=5). Tissue was cryopreserved in OCT and serial sections were cut using a cryostat. Sections were stained and epithelial and stromal cells were isolated by laser capture microdissection. Total RNA was isolated and target was prepared using NuGen Ribo-SPIA Ovation Technology. Gene expression was measured using Affymetrix U133A 2.0 GeneChips. Gene expression differences were evaluated using a linear model of the Robust Multichip Average gene expression statistic, a model that accounted for cell type (E and S), patient diagnosis (C and N), as well as cell type-diagnosis interactions. Data were examined to determine false discovery rate and were filtered for fold changes in gene expression and p-value.
| S-ECPF-GEOD-10797 | biostudies-other
Project description:The genetic regulation of the human epigenome is not fully appreciated. Here we describe the effects of genetic variants on the DNA methylome in human lung based on methylation-quantitative trait loci (meQTL) analyses. We report 34,304 cis- and 585 trans-meQTLs, a genetic-epigenetic interaction of surprising magnitude, including a regulatory hotspot. These findings are replicated in both breast and kidney tissues and show distinct patterns: cis-meQTLs mostly localize to CpG sites outside of genes, promoters and CpG islands (CGIs), while trans-meQTLs are over-represented in promoter CGIs. meQTL SNPs are enriched in CTCF-binding sites, DNaseI hypersensitivity regions and histone marks. Importantly, four of the five established lung cancer risk loci in European ancestry are cis-meQTLs and, in aggregate, cis-meQTLs are enriched for lung cancer risk in a genome-wide analysis of 11,587 subjects. Thus, inherited genetic variation may affect lung carcinogenesis by regulating the human methylome.
| S-EPMC3982882 | biostudies-literature
Project description:Cancer evolves dynamically, as clonal expansions supersede or overlap one another, driven by shifting selective pressures, mutational processes and disrupted cancer genes. These processes mark the genome, such that a cancer's life history is encrypted in the timing, ploidy, clonality and patterns of somatic mutation. We developed bioinformatic algorithms to decipher this narrative, and applied them to 21 breast cancer genomes. We find that mutational processes evolve across the lifespan of a breast tumor, with cancer-specific signatures of point mutations and chromosomal instability often emerging late but contributing extensive genetic variation. Subclonal diversification is prominent, providing insight into the dynamics of clonal expansion in breast cancer. Most point mutations are found in just a fraction of tumor cells, together with frequent variegation in chromosomal copy number. Every tumor studied here has a dominant subclonal lineage, representing more than 50% of tumor cells. Minimal expansion of these subclones occurs until many hundreds to thousands of mutations have accumulated, implying the existence of long-lived, quiescent lineages of cells that are capable of substantial proliferation upon acquisition of enabling genomic changes. Expansion of the dominant subclone to an appreciable mass may therefore represent the final rate-limiting step in a breast cancer's development, triggering diagnosis.
| S-ECPF-MTAB-1088 | biostudies-other