Project description:Myxoid liposarcoma (MLS) is the second most common type of liposarcoma, and today few model systems to study the disease exists. To be able to model the disease in vitro, cell-free scaffolds from MLS patient-derived xenograft (PDX) models were generated. The MLS scaffolds were then used as a 3D growth platform for MLS cell lines to study the cancer microenvironments impact on cellular heterogeneity using RNA sequencing. Key components in the microenvironment have also been shown to influence the fraction of cellular subpopulations, such as cancer stem cells and migratory cells but also to promote aggressive features of cancers. Therefore, to better understand and characterize these scaffolds, protein analyses were performed and links between scaffold compositions and the induced gene expression profiles of the cells grown therein could be made. This model system provides a better insight to the composition of the cell-free cancer microenvironment in a rare disease, which can lead to identification of novel malignancy inducing properties in MLS.
Project description:Telomere shortening can cause detrimental diseases and contribute to aging. It occurs due to the end replication problem in cells lacking telomerase. In addition, recent evidence revealed that telomere shortening can be attributed to difficulties of the semi-conservative DNA replication machinery to replicate through the bulk of telomeric DNA repeats. To investigate telomere replication in a comprehensive manner, we developed QTIP-iPOND, which enables purification of the proteins that associate with telomeres during their replication. We identify in addition to the core replisome a large number of proteins that specifically associate with telomere replication forks and validate their importance.
Project description:Non-coding variants coordinate transcription factor (TF) binding and chromatin mark enrichment changes over regions spanning >100 kb. We named these molecularly coordinated regions “variable chromatin modules” (VCMs), providing a conceptual framework of how regulatory variation might shape complex traits. To better understand the molecular mechanisms underlying VCM formation, here, we mechanistically dissect an uncharacterized VCM-modulating non-coding variant that is associated with reduced chronic lymphocytic leukemia (CLL) predisposition and disease progression. This common, germline variant constitutes a 5-bp indel that controls the activity of an AXIN2 gene-linked VCM by creating a MEF2 binding site, which, upon binding, activates a super-enhancer-like regulatory element. This triggers a big change in TF binding activity and chromatin state at an enhancer cluster spanning >150 kb, coinciding with long-range chromatin compaction and AXIN2 up-regulation. Our results support a model in which the indel acts as an AXIN2 VCM-activating TF nucleation event, which modulates CLL pathology.
Project description:Investigation of whole genome expression pattern of 60 and 72 hours post fertilization Danio Rerio embryos exposed to TMT and vehicle control Embryos were exposed to 10uM TMT or control from 48hpf to 60 or 72 hpf. Three replicates were collected for each time point. 40 embryos were pooled to comprise a replicate.
Project description:The rat pheochromocytoma cell line PC12 cells were cultured in complete DMEM till 80% confluence, then placed at 5000 cells per squared cm. Cells were then plated in 24-well plates for cell viability assay and in T75 flasks for RNA isolation. Medium was replaced with serum-free fresh medium for 12 hours prior to TMT treatment. Gene expression patterns were then analysed using Rat Expression Array 230A Experiment Overall Design: In this study we analize gene expression patterns in PC12 cells treated with Trimethyltin (TMT). We utilized control cells (untreated) and two different concentration (1 and 5) Experiment Overall Design: We used three biological replicates, for the three concentration tested, according to MIAME guidelines Experiment Overall Design: (total 9 chips were used in this study).
Project description:We performed DNA-protein interaction (ChIP-seq) analyses for Helicobacter pylori N6 wild-type (WT) and HP1021 deletion mutant (ΔHP1021::aphA-3) under oxidative stress (21% O2) and optimal microaerobic growth (5% O2) conditions. We detected 100 binding sites of HP1021 on the H. pylori N6 chromosome, most of which are promoter-located, likely affecting gene transcription. 84 of 100 identified HP1021 binding sites were located near promoter regions. EMSA and ChIP-qPCR confirmed the binding of HP1021 to the promoter region of a few genes.
Project description:Neisseria gonorrhoeae (GC) is a human-specific pathogen, and the agent of a sexually transmitted disease, gonorrhea. There is a critical need for new approaches to study and treat GC infections because of the growing threat of multidrug-resistant isolates and the lack of a vaccine. Despite the implied role of the GC cell envelope and membrane vesicles in colonization and infection of human tissues and cell lines, comprehensive studies have not been undertaken to elucidate their constituents. Accordingly, in pursuit of novel molecular therapeutic targets, we have applied isobaric tagging for absolute quantification coupled with liquid chromatography and mass spectrometry for proteome quantitative analyses. Mining the proteome of cell envelopes and native membrane vesicles revealed 533 and 168 common proteins, respectively, in analyzed GC strains FA1090, F62, MS11, and 1291.
Project description:Chromatin plays a crucial role in the intermediation between cell signaling and gene expression. The nucleolus is sensitive to stress and can orchestrate a chain of cellular events in response to stress signals. Despite being a growth factor, FGF2 has anti-proliferative and tumor-suppressive functions in some cellular contexts. In this work, we investigated how the antiproliferative effect of FGF2 modulates chromatin, nucleolus, and rDNA-associated proteins. The chromatin and nucleolar proteome indicated that FGF2 stimulation modulates proteins related to transcription regulation, particularly rRNA expression, and chromatin remodeling proteins. Upon 24 hrs of FGF2 stimulation, the global transcriptional rate and nucleolus area increased along with intense nucleolar disorganization detected by fibrillarin dispersion and electron microscopy analyses. We confirmed that FGF2 stimulation induced immature rRNA accumulation by increasing rRNA transcription regardless of changes in ribosome profiling. The rDNA-associated protein analysis reinforced that FGF2 stimulus interferes with transcription and rRNA processing/modification, since the proteins Nolc1 and Tcof1 were upregulated after FGF2 stimulation. Changes in rRNA expression may be crucial for triggering the antiproliferative effect induced by FGF2 since inhibiting RNA Pol I, responsible for rRNA expression, partially reversed the growth arrest induced by FGF2. Taken together, we demonstrate that the antiproliferative FGF2 stimulus triggers significant transcriptional changes and modulates the main cell transcription site, the nucleolus, directly modulating the proteome of the rDNA loci.