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GSE31637
Mus musculus
3 Downloadable Samples
Description
BRCA1, a well-known breast and ovarian cancer susceptibility gene with multiple interacting partners, is predicted to have diverse biological functions. However, to date its only well-established role is in the repair of damaged DNA and cell cycle regulation. In this regard, the etiopathological study of low penetrant variants of BRCA1 provides an opportunity to uncover its other physiologically important functions. Using this rationale, we studied the R1699Q variant of BRCA1, a potentially moderate risk variant, and found that it does not impair DNA damage repair but abrogates the repression of miR-155, a bona fide oncomir. We further show that in the absence of functional BRCA1, miR-155 is up-regulated in BRCA1-deficient mouse mammary epithelial cells, human and mouse BRCA1-deficienct breast tumor cell lines as well as tumors. Mechanistically, we found that BRCA1 represses miR-155 expression via its association with HDAC2, which deacetylates H2A and H3 on the miR-155 promoter. Finally, we show that over-expression of miR-155 accelerates whereas the knockdown of miR-155 attenuates the growth of tumor cell lines in vivo. Taken together, our findings demonstrate a new mode of tumor suppression by BRCA1 and reveal miR-155 as a potential therapeutic target for BRCA1-deficient tumors.
Publication Title
Tumor suppressor BRCA1 epigenetically controls oncogenic microRNA-155.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 3 Downloadable Samples
Description
We examined the functional significance of the R1699Q variant of human BRCA1 gene using a mouse ES cell-based assay.
Publication Title
Tumor suppressor BRCA1 epigenetically controls oncogenic microRNA-155.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 7 Downloadable Samples
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
DNA methylation profiling of embryonic stem cell differentiation into the three germ layers.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 7 Downloadable Samples
Description
Embryogenesis is tightly regulated by multiple levels of epigenetic systems such as DNA methylation, histone modification, and chromatin remodeling. DNA methylation patterns are erased in primordial germ cells and in the interval immediately following fertilization. Subsequent reprogramming occurs by de novo methylation and demethylation. Variance of DNA methylation patterns between different cell types is not well understood. Here, using methylated DNA immunoprecipitation and tiling array technology, we have comprehensively analysed DNA methylation patterns at proximal promoter regions in mouse embryonic stem (ES) cells, ES cell-derived early germ layers (ectoderm, endoderm and mesoderm) and four adult tissues (brain, liver, skeletal muscle and sperm). Most of the methylated regions in the three germ layers and in the three adult somatic tissues are shared in common. This commonly methylated gene set is enriched in germ cell associated genes that are generally transcriptionally inactive in somatic cells. We also compared DNA methylation patterns with global mapping of histone H3 lysine 4/27 trimethylation, and found that gain of DNA methylation correlates with loss of histone H3 lysine 4 trimethylation. Taken together, our findings indicate that differentiation from ES cells to the three germ layers is accompanied by an increase in the number of commonly methylated DNA regions and that these tissue-specific alterations are present for only a small number of genes. Our findings indicate that DNA methylation at the proximal promoter regions of commonly methylated genes act as an irreversible mark which fixes somatic lineage by repressing transcription of germ cell specific genes.
Publication Title
DNA methylation profiling of embryonic stem cell differentiation into the three germ layers.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 3 Downloadable Samples
Description
The cellular ontogeny of hematopoietic stem cells (HSCs) remains poorly understood because their isolation from and their identification in early developing small embryos are difficult. We attempted to dissect early developmental stages of HSCs using an in vitro mouse embryonic stem cell (ESC) differentiation system combined with inducible HOXB4 expression. Here we report the identification of pre-HSCs and an embryonic type of HSCs (embryonic HSCs) as intermediate cells between ESCs and HSCs. Both pre-HSCs and embryonic HSCs were isolated by their c-Kit+CD41+CD45- phenotype. Pre-HSCs did not engraft in irradiated adult mice. After co-culture with OP9 stromal cells and conditional expression of HOXB4, pre-HSCs gave rise to embryonic HSCs capable of engraftment and long-term reconstitution in irradiated adult mice. Blast colony assays revealed that most hemangioblast activity was detected apart from the pre-HSC population, implying the early divergence of pre-HSCs from hemangioblasts. Gene expression profiling suggests that a particular set of transcripts closely associated with adult HSCs is involved in the transition of pre-HSC to embryonic HSCs.
Publication Title
Stepwise development of hematopoietic stem cells from embryonic stem cells.
Sample Metadata Fields
Treatment
View Samples- Mus musculus, Homo sapiens
- 4 Downloadable Samples
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
MEK inhibition induces MYOG and remodels super-enhancers in RAS-driven rhabdomyosarcoma.
Sample Metadata Fields
Treatment, Time
View Samples- Mus musculus
- 4 Downloadable Samples
Description
C2C12 mouse myoblasts expressing RAS mutants identified in human tumors fail to differentiate in low serum media.
Publication Title
MEK inhibition induces MYOG and remodels super-enhancers in RAS-driven rhabdomyosarcoma.
Sample Metadata Fields
No sample metadata fields
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