Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA174769 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:BRCA1 inactivation is a hallmark of familial breast cancer, often encountered in aggressive triple negative breast cancers. BRCA1 is a tumor suppressor with known functions in DNA repair, transcription regulation, cell cycle control, and apoptosis. In the present study, we demonstrate that BRCA1 is also a translational regulator. Based on the combination of RNA-binding protein immunoprecipitation and microarray analysis, as well as polysome profiling, we identified a subset of mRNAs translationally regulated by BRCA1 and coding for proteins whose functions play major role in cancer. We found that the level of these key proteins is similarly controlled in human mammary tumors according to their BRCA1-status. Therefore, our results propose translational control as a novel molecular mechanism with clinical relevance through which BRCA1 is a tumor suppressor.
2020-05-21 | GSE119886 | GEO
Project description:Microarrays were used to determine relative global gene expression changes in WT and BRCA1-mutation carrier breast epithelium as well as tumors created from WT and BRCA1-mutation carrier breast epithelial cells. Total RNA was isolated from freshly dissociated mammary epithelilal cells obtained from disease-free prophylactic masectomy tissues of 4 different BRCA1-mutation carriers or 4 different reduction mammoplasty tissues from non-mutation carriers. Total RNA was also isolated from fresh tumor tissues derived from in vivo transformed human mammary epithelial cells created from cells obtained from WT or BRCA1-muation carrires. Dissociated mammary epithelial cells were transduced with lentiviruses encoding mutant p53, mutant ras, mutant PI3K and cyclin D1 and injected into in humanized glands. There were four tumor tissues isolated for each genetic background.
2011-02-04 | E-GEOD-25835 | biostudies-arrayexpress
Project description:Loss of function of the tumor suppressor BRCA1 (Breast Cancer 1) protein is responsible for numerous familial and sporadic breast cancers. We previously identified PABP1 as a novel BRCA1 partner and showed that BRCA1 modulates translation through its interaction with PABP1. We showed that the global translation was diminished in BRCA1-depleted cells and increased in BRCA1-overexpressing cells. Our findings raised the question whether BRCA1 affects translation of all cytoplasmic cellular mRNAs or whether it specifically targets a subset of mRNAs. In the present study, we investigated which mRNAs are regulated by BRCA1 using a microarray analysis of polysome-associated RNAs from BRCA1-depleted MCF7 cells, a human breast cancer cell line. We isolated mRNAs from the high-molecular-weight polysomes (fractions 12 to 18) and total cellular cytoplasmic mRNAs from the cytoplasmic fraction of MCF7 cells transiently expressing either siRNA directed against BRCA1 or control siRNA. Since we were interested in identifying the mRNAs that were translationally regulated by BRCA1, we determined the relative translatability of each mRNA. The relative translatability of an mRNA was determined by normalizing the change in abundance in polysomal mRNA to the change in abundance in total cytoplasmic mRNA for each mRNA.
2013-12-31 | E-GEOD-40730 | biostudies-arrayexpress
Project description:The mammary gland at early stages of pregnancy undergoes fast cell proliferation, yet the mechanism to ensure its genome integrity is largely unknown. Here we show that pregnancy enhances expression of genes involved in numerous pathways, including most genes encoding replisomes. In mouse mammary glands, replisome genes are positively regulated by estrogen/ERa signaling but negatively regulated by BRCA1. Upon DNA damage, BRCA1 deficiency markedly enhances DNA replication initiation. BRCA1 deficiency also preferably impairs DNA replication checkpoints mediated by ATR and CHK1 but not by WEE1, which inhibits DNA replication initiation through CDC7-MCM2 pathway and enables BRCA1-deficient cells to avoid further genomic instability. Thus, BRCA1 and WEE1 inhibit DNA replication initiation in a parallel manner to ensure genome stability for mammary gland development during pregnancy.
2018-12-11 | GSE92342 | GEO
Project description:BRCA1 exerts transcriptional repression through interaction with CtIP in the C-terminal BRCT domain and ZBRK1 in the central domain. A dozen of genes including angiopoietin-1 (ANG1), a secreted angiogenic factor, are co-repressed by BRCA1 and CtIP based on microarray analysis of mammary epithelial cells in 3-D culture. BRCA1, CtIP and ZBRK1 form a complex that coordinately represses ANG1 expression via a ZBRK1 recognition site in ANG1 promoter. Impairment of this complex upregulates ANG1, which stabilizes endothelial cells forming capillary-like network structure. Consistently, Brca1-deficient mouse mammary tumors exhibit accelerated growth, pronounced vascularization and overexpressed ANG1. These results suggest, besides its role in maintaining genomic stability, BRCA1 directly regulates the expression of angiogenic factors to modulate the tumor microenvironment. Keywords: MCF10A, human mammary epithelial cells, 3-D Matrigel, 15 h, BRCA1-RNAi
2006-05-02 | GSE4750 | GEO
Project description:BRCA1 exerts transcriptional repression through interaction with CtIP in the C-terminal BRCT domain and ZBRK1 in the central domain. A dozen of genes including angiopoietin-1 (ANG1), a secreted angiogenic factor, are co-repressed by BRCA1 and CtIP based on microarray analysis of mammary epithelial cells in 3-D culture. BRCA1, CtIP and ZBRK1 form a complex that coordinately represses ANG1 expression via a ZBRK1 recognition site in ANG1 promoter. Impairment of this complex upregulates ANG1, which stabilizes endothelial cells forming capillary-like network structure. Consistently, Brca1-deficient mouse mammary tumors exhibit accelerated growth, pronounced vascularization and overexpressed ANG1. These results suggest, besides its role in maintaining genomic stability, BRCA1 directly regulates the expression of angiogenic factors to modulate the tumor microenvironment. Keywords: MCF10A, human mammary epithelial cells, 3-D Matrigel, 15 h, CtIP-RNAi
2006-05-02 | GSE4751 | GEO
Project description:We utilized a genetic tool termed Mosaic Analysis with Double Markers (MADM) to achieve a sporadic loss of heterozygosity of Brca1 & Trp53 in mouse mammary epithelial cells and concomitantly label them with GFP. This MADM-based mouse model initiated cancer with sparse GFP+ mutant cells and developed mammary tumors that resemble human disease at pathological, transcriptomic, and genomic levels. This dataset provides bulk RNA sequencing of twelve mammary tumors from MADM Brca1-Trp53 animals.
2023-10-16 | GSE214433 | GEO
Project description:Women carrying BRCA1 (B1) mutations face an elevated risk of developing breast cancer, yet effective preventive strategies remain limited. To design innovative strategies, it is critical to understand the early events driving tumorigenesis. Here we present a unique mouse model which is conditionally heterozygous for B1 and deleted for Trp53, specifically in the mammary epithelial cells, and forms triple-negative mammary tumors under replication stress. Our single-cell RNA sequencing analysis, spanning various stages of mammary tumorigenesis in this model, reveals early tumor-promoting transcriptomic alterations. We identify a distinct, proliferative bi-potent cell population expressing both luminal progenitor and basal epithelial markers, uniquely enriched in Brca1 heterozygous mammary tissue upon replication stress. Notably, the transcriptomic changes in this population correlate with poor outcomes in human breast cancer. Transcriptomic analysis, combined with transcription factor analysis, along the trajectory from normal to precancerous and tumor stages, implicates the AP-1 complex, specifically the FRA-1 transcription factor, as an early driver in BRCA1 mutant breast cancer. Furthermore, pseudo-time analysis along this trajectory identifies alveolar luminal progenitor cells as the likely cell-of-origin. Luminal cells also show reduced efficiency of DNA damage repair when compared to basal cells. In conclusion, we have established the first Brca1 heterozygous mouse model for studying the effects of DNA replication stress on breast cancer and have identified early precancerous transcriptomic changes stemming from BRCA1 haploinsufficiency and replication stress. This study provides critical insights into the molecular mechanisms that drive breast cancer in BRCA1 mutation carriers.
2024-10-01 | GSE255547 | GEO
Project description:Breast cancer is the most common cancer in females, affecting one in every eight women and accounting for the majority of cancer-related deaths in women worldwide. Germline mutations in the BRCA1 and BRCA2 genes are significant risk factors for specific subtypes of breast cancer. BRCA1 mutations are associated with basal-like breast cancers, whereas BRCA2 mutations are associated with luminal-like disease. Defects in mammary epithelial cell differentiation have been previously recognized in germline BRCA1/2 mutation carriers even before cancer incidence. However, the underlying mechanism is largely unknown. Here, we employ spatial transcriptomics to investigate defects in mammary epithelial cell differentiation accompanied by distinct microenvironmental alterations in preneoplastic breast tissues from BRCA1/2 mutation carriers and normal breast tissues from non-carrier controls. We uncovered spatially defined receptor-ligand interactions in these tissues for the investigation of autocrine and paracrine signaling. We discovered that β1-integrin-mediated autocrine signaling in BRCA2-deficient mammary epithelial cells may differ from BRCA1-deficient mammary epithelial cells. In addition, we found that the epithelial-to-stromal paracrine signaling in the breast tissues of BRCA1/2 mutation carriers is greater than in control tissues. More integrin-ligand pairs were differentially correlated in BRCA1/2-mutant breast tissues than non-carrier breast tissues with more integrin receptor-expressing stromal cells. Implications: These results suggest alterations in the communication between mammary epithelial cells and the microenvironment in BRCA1 and BRCA2 mutation carriers, laying the foundation for designing innovative breast cancer chemo-prevention strategies for high-risk patients.
2023-10-11 | GSE234017 | GEO
Project description:We compared the expression levels of X-linked genes in the mammary glands of Brca1 D11/D11;p53+/- mutant and control (p53+/-) mice at three different stages of the mammary cycle: virgin, pregnant day 16.5, and lactation day 1, using a cDNA microarray. In about 690 X-linked genes that are expressed at these three stages of mammary cycle of development, we found 16 X-linked genes showed altered expression levels in Brca1 D11/D11;p53+/- mammary glands in comparison with controls at all three time points. Among them, 9 genes were up-regulated and 7 were down-regulated. This result indicates that mutation of Brca1 could affect expression of a few X-linked genes in mammary tissues. However, this was unlikely caused by failure of X chromosome inactivation, as seven of them were down-regulated, and Xist RNA was expressed in all the Brca1 mutant mammary tissues. Keywords: BRCA1 mutation analysis
2006-09-19 | GSE5861 | GEO