Project description:The eukaryotic transcriptional Mediator comprises a large Core (cMED) and a dissociable CDK8 kinase module (CKM). cMED recruits RNA polymerase II (Pol II) and promotes pre-initiation complex formation in a manner repressed by the CKM through mechanisms presently unknown. Herein we report cryo-electron microscopy structures of the complete human Mediator and its CKM. Combined with biochemical and functional analyses, these structures provide a mechanistic framework to explain the basis for CKM-mediated repression of cMED function. The CKM binds to cMED at multiple sites through both MED12 and a large intrinsically disordered region (IDR) in MED13. The MED13 IDR blocks Pol II/MED26 recruitment onto cMED by direct occlusion of their corresponding binding sites, leading to functional repression of cMED-dependent transcription. Notably, the CKM is anchored to the cMED Hook, positioning CDK8 downstream and proximal to the transcription start site, which sheds new light on its stimulatory function in post-initiation events.
Project description:In order to identify the targets of miR-193a-5p in osteosarcoma U2OS cell line, we used a lentivirus-mediated expression system to overexpressing miR-193a precusor, miR-193a-5p target sequence and non-target sequence, respectively, in osteosarcoma cell line U2OS. A tandem mass tag (TMT)-based quantitative proteomic strategy was employed to identify the global profile of miR-193a-5p-regulated proteins. order to identify the targets of miR-193a-5p, we used a lentivirus-mediated expression system to overexpressing miR-193a precusor, miR-193a-5p target sequence and non-target sequence, respectively, in osteosarcoma cell line U2OS. A tandem mass tag (TMT)-based quantitative proteomic strategy was employed to identify the global profile of miR-193a-5p-regulated proteins.
Project description:To identify target genes regulated by ALKBH5 in osteosarcoma, we silenced the expression of ALKBH5 in osteosarcoma cell line-U2OS and tested its effect on U2OS transcriptome.
Project description:Transcriptional profiling of MSC, Osteoblasts and U2OS cells. The aim was to quantitate relative gene expression in MSC, osteoblasts and U2OS. MSC and osteoblasts were used as normal cells in this study because osteosarcoma most likely originates from MSC or osteoblasts.
Project description:This SuperSeries is composed of the following subset Series: GSE27900: Gene expression analysis of mesenchymal stem cells (MSC), osteoblasts and the U2OS (osteosarcoma) cell line GSE35573: ChIP-seq analysis of H3K4Me3- and H3K27Me3-marked chromatin in mesenchymal stem cells (MSCs), osteoblasts derived from MSCs and the osteosarcoma cell line U2OS Refer to individual Series
Project description:The study compares the transcriptional profiles of U2OS human osteosarcoma cells and those of two single-cell derived sub-lines carrying a stably integrated H2BmCherry (U2OS-R1) or H2B-YFP (U2OS-YFP) expression cassette. U2OS-R1 and U2OS-YFP cell spontaneously undergo apoptosis upon co-culture with the parental (Wt) U2OS cell population. Furthermore, YFP cells also undergo apoptosis upon co-culture with R1 cells. This behavior is similar to the \cell competition\ phenomenon described in the Drosophila imaginal disc and the mouse epiblast (for review, see , where fast-growing \fit\ cells induce apoptosis in slow-growing, less \fit\ neighbors. The mRNA expression profiles of Wt, R1 and YFP cells cultured alone or in pairwise combinations for 48h were analyzed after cell sorting by RNA microarray hybridization using Affymetrix Human Gene ST 1.0 chips.
Project description:We used next generation sequencing to analyze the gene expression changes in U2OS osteosarcoma cells expressing shRNA targeting the promyelocytic leukemia (PML) gene transcripts
Project description:We have recently established a panel of mutant U2OS human osteosarcoma cells lacking either REV-ERBα or REV-ERBβ (encoded by NR1D1 and NR1D2 genes, respectively) expression by a CRISPR/Cas9 and dual sgRNA-mediated gene deletion strategy. We then intended to dissect redundant and isoform-specific roles of these circadian nuclear receptors in controlling their target genes by comparing transcriptome profiles among wild-type and mutant U2OS cells.
Project description:The Bromo-domain and PHD-finger protein, BRPF3, forms a complex with HBO1 and regulates the initiation of DNA replication. BRPF3-dependent histone H3K14 enriched in chromatin surrounding a fraction of replication origins may play an important role in origin firing. We used microarrays to evaluate whether replication defect due to the lack of BRPF3 is associated with transcriptional changes of replication genes. Human osteosarcoma U2OS cells depleted for BRPF3 were used for RNA extraction and hybridization on Affymetrix microarrays. Cells were treated with either scamble siRNA (Control_1_B1) or siRNA against BPRF3 (BRPF3_B1) for 48 hours. Two samples in a biological replica set were prepared in exactly the same way and labeled as Control_1_B2 and BRPF3_B2 respectively.