LOXL2 aids the formation of BRD4S and MED1 transcriptional foci to control cell cycle gene expression in triple-negative breast cancer
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ABSTRACT:
PROVIDER: PRJNA816330 | ENA |
REPOSITORIES: ENA
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Project description:Triple-negative breast cancer (TNBC) often develops resistance to single-agent treatment, which can be circumvented using targeted combinatorial approaches. Here, we demonstrate that the simultaneous inhibition of LOXL2 and BRD4 synergistically limits TNBC proliferation in vitro and in vivo. Mechanistically, LOXL2 interacts in the nucleus with the short isoform of BRD4 (BRD4S), MED1, and the cell cycle transcriptional regulator B-MyB. These interactions sustain the formation of BRD4 and MED1 nuclear transcriptional foci and control cell cycle progression at the gene expression level. The pharmacological co-inhibition of LOXL2 and BRD4 reduces BRD4 nuclear foci, BRD4-MED1 colocalization, and the transcription of cell cycle genes, thus supressing TNBC cell proliferation. Finding novel strategies to disrupt BRD4S-LOXL2 interaction holds potential for developing successful TNBC therapies.
2022-03-18 | GSE198647 | GEO
Project description:Med1 overexpression leads to induction of a wide spectrum of genes. Adenovirally-driven overexpression of Med1 in mouse liver stimulates hepatocyte DNA synthesis with enhanced expression of DNA replication, cell cycle control and liver specific genes as observed at day 3 and day 5 post injection. Med1 gene is amplified in a number of cancers so in this study we tested the hypothesis that Med1 by itself has the capacity to induce cell proliferation. Analysis of the Med1- induced gene expression showed a robust induction of a wide spectrum of genes involved in hepatocellular proliferation. Med1 floxed mice (Med1fl/fl) were injected with Ad-His-Med1 (adenovirus expressing Med1 gene) via tail vein and killed 3 or 5 days after injection. Ad-LacZ (adenovirus expression beta-galactosidase gene) injected mouse liver served as control. Total RNA were isolated from the liver and subjected to the microarray.
2013-07-18 | E-GEOD-48950 | biostudies-arrayexpress
Project description:Med1 overexpression leads to induction of a wide spectrum of genes. Adenovirally-driven overexpression of Med1 in mouse liver stimulates hepatocyte DNA synthesis with enhanced expression of DNA replication, cell cycle control and liver specific genes as observed at day 3 and day 5 post injection. Med1 gene is amplified in a number of cancers so in this study we tested the hypothesis that Med1 by itself has the capacity to induce cell proliferation. Analysis of the Med1- induced gene expression showed a robust induction of a wide spectrum of genes involved in hepatocellular proliferation.
2013-07-18 | GSE48950 | GEO
Project description:Kaposi's Sarcoma (KS) is a proliferation of aberrant vascular structures lined by spindle cells, and is caused by a gammaherpes virus (HHV8/KSHV). Its course is aggravated by co-infection with HIV-1, where the timing of infection with HIV-1 and HHV8 is important for the clinical outcome. METHODS: In order to better understand the pathogenesis of KS, we have analysed tissue from two AIDS-KS lesions, and from normal skin by serial analysis of gene expression (SAGE). Semi-quantitative RT-PCR was then used to validate the results. RESULTS: The expression profile of AIDS-related KS (AIDS-KS) reflects an active process in the skin. Transcripts of HHV8 were found to be very low, and HIV-1 mRNA was not detected by SAGE, although it could be found using RT-PCR. Comparing the expression profile of AIDS-KS tissue with publicly available SAGE libraries suggested that AIDS-KS mRNA levels are most similar to those in an artificially mixed library of endothelial cells and leukocytes, in line with the description of KS lesions as containing spindle cells with endothelial characteristics, and an inflammatory infiltrate. At least 64 transcripts were found to be significantly elevated, and 28 were statistically downregulated in AIDS-KS compared to normal skin. Five of the upregulated mRNAs, including Tie 1 and sialoadhesin/CD169, were confirmed by semi-quantitative PCR to be elevated in additional AIDS-KS biopsies. Antibodies to sialoadhesin/CD169, a known marker of activated macrophages, were shown to specifically label tumour macrophages. CONCLUSION: The expression profile of AIDS-KS showed 64 genes to be significantly upregulated, and 28 genes downregulated, compared with normal skin. One of the genes with increased expression was sialoadhesin (CD169). Antibodies to sialoadhesin/CD169 specifically labelled tumour-associated macrophages, suggesting that macrophages present in AIDS-KS lesions belong to a subset of human CD169+ macrophages. Keywords: other
2003-07-16 | GSE514 | GEO
Project description:We performed RNA-seq and ChIP-seq in three prostate cell lines (VCaP, LNCaP and DU145) to ascertain the role of the mediator complex MED1 in AR signaling. Upon androgen stimulation, MED1 undergoes phosphorylation by CDK7 and physically engages with AR at super-enhancer sites, which is essential for AR-mediated transcription. The CDK7 specific inhibitor THZ1 blunts AR-dependent neoplastic growth by preventing the co-recruitment of AR/MED1 in a genome-wide fashion, and reverts the enzalutamide resistance characterized by hyper-phosphorylated MED1. The effect of THZ1 phenocopies that for MED1 and CDK7 knockdown.
2019-08-20 | GSE125245 | GEO
Project description:Oxidation of histone H3 at lysine 4 (H3K4ox) is catalyzed by lysyl oxidase–like 2 (LOXL2). This histone modification is enriched in heterochromatin in triple-negative breast cancer (TNBC) cells and has been linked to the maintenance of compacted chromatin. However, the molecular mechanism underlying this maintenance is still unknown. Here we show that LOXL2 interacts with RUVBL1, RUVBL2, BAF53, and DMAP1, a complex involved in the incorporation of the histone variant H2A.Z. Our experiments indicate that this interaction and the active form of RUVBL2 are required to maintain LOXL2-dependent chromatin compaction. Genome-wide experiments showed that H2A.Z, RUVBL2, and H3K4ox colocalize in heterochromatin regions. In the absence of LOXL2 or RUVBL2, global levels of the heterochromatin histone mark H3K9me3 were strongly reduced, and the ATAC-seq signal in the H3K9me3 regions was increased. Finally, we observed that the interplay between these series of events is required to maintain H3K4ox-enriched heterochromatin regions, which in turn is key for maintaining the oncogenic properties of the TNBC cell line tested (MDA-MB-231).
2023-12-31 | GSE142463 | GEO
Project description:MED1 often serves as a surrogate of the general transcription coactivator complex Mediator for identifying active enhancers. MED1 is required for phenotypic conversion of fibroblasts to adipocytes in vitro but its role in adipose development and expansion in vivo has not been reported. Here we show that MED1 is not generally required for transcription during adipogenesis in culture and that MED1 is dispensable for adipose development in mice. Instead, MED1 is required for postnatal adipose expansion and the induction of fatty acid and triglyceride synthesis genes after pups switch diet from high-fat maternal milk to carbohydrate-based chow. During adipogenesis, MED1 is dispensable for induction of lineage-determining transcription factors (TFs) PPARγ and C/EBPα but is required for lipid accumulation in the late phase of differentiation. Mechanistically, MED1 controls the induction of lipogenesis genes by facilitating lipogenic TF ChREBP- and SREBP1a-dependent recruitment of Mediator to active enhancers. Together, our findings identify a cell- and gene-specific regulatory role of MED1 as a lipogenesis coactivator required for postnatal adipose expansion.
2021-03-17 | GSE160605 | GEO
Project description:CRISPR/Cas9 system was used to generate mediator complex subunit 1 (MED1) knockout human pre-B ALL cell line 697. ChIP-seq was performed to identify genomic regions responsible for recruitment of MED1 and RUNX1.
2020-05-13 | E-MTAB-8177 | biostudies-arrayexpress