Non-steroidal anti-inflammatory drugs, principally aspirin (acetylsalicylic acid, ASA), have anti-neoplastic properties, as shown by epidemiological studies on colorectal cancer and many other types of tumours. The chemopreventive and anti-proliferative properties of aspirin towards tumour cells have been shown to be due to the induction of programmed cell death such as apoptosis. Yeast cells are among the experimental models used extensively for the study of oxidative stress and apoptosis in living organisms because yeast, such as S. cerevisiae, retains many of the core eukaryotic cellular processes, including the hallmarks of eukaryotic apoptosis. An important contribution of our previous work has been the clarification of the critical defensive role of the antioxidant mitochondrial enzyme manganese superoxide dismutase (MnSOD) against apoptosis, confirmed to be the attenuation of aspirin-induced superoxide radical accumulation in the yeast mitochondria (Farrugia et al. (2013) FEMS Yeast Res 13, 755-768). To study the possible differential expression of gene transcripts in relation to the induction of apoptosis by aspirin, we used gene expression profiling by means of GeneChip Microarray Technology (Affymetrix). The yeast strains considered for this study included (1) the wild type strain S. cerevisiae EG103, which contains both MnSOD and cytosolic copper, zinc superoxide dismutase (CuZnSOD) and (2) the redox-compromised MnSOD-deficient S. cerevisiae EG110 strain. [This work was financed by the Malta Council for Science and Technology through the R&I Technology Development Programme (Project R&I-2015-001)].
Aspirin impairs acetyl-coenzyme A metabolism in redox-compromised yeast cells.
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View SamplesKAP1 (TRIM28) is a transcriptional regulator in embryonic development that controls stem cell self-renewal, chromatin organization and the DNA damage response, acting as an essential co-repressor for KRAB family zinc finger proteins (KRAB-ZNF). To gain insight into the function of this large gene family, we developed an antibody that recognizes the conserved zinc fingers linker region (ZnFL) in multiple KRAB-ZNF. Here we report that the expression of many KRAB-ZNF along with active SUMOlyated KAP1 is elevated widely in human breast cancers. KAP1 silencing in breast cancer cells reduced proliferation and inhibited the growth and metastasis of tumor xenografts. Conversely, KAP1 overexpression stimulated cell proliferation and tumor growth. In cells where KAP1 was silenced, we identified multiple downregulated genes linked to tumor progression and metastasis, including EREG/epiregulin, PTGS2/COX2, MMP1, MMP2 and CD44, along with downregulation of multiple KRAB-ZNF proteins. KAP1-dependent stabilization of KRAB-ZNF required direct interactions with KAP1. Together, our results show that KAP1-mediated stimulation of multiple KRAB-ZNF contributes to the growth and metastasis of breast cancer.
KAP1 promotes proliferation and metastatic progression of breast cancer cells.
Cell line
View SamplesApproximately 30% of women diagnosed with ERa breast cancer relapse with metastatic disease following adjuvant treatment with endocrine therapies. The connection between acquisition of drug resistance and invasive potential is poorly understood. In this study, we demonstrate that the type II keratin topological associating domain (TAD) undergoes epigenetic reprogramming in cells that develop resistance to aromatase inhibitors (AI), leading to keratin 80 (KRT80) upregulation. In agreement, an increased number of KRT80-positive cells are observed at relapse in vivo while KRT80 expression associates with poor outcome using several clinical endpoints. KRT80 expression is driven by de novo enhancer activation by sterol regulatory element-binding protein 1 (SREBP1). KRT80 upregulation directly promotes cytoskeletal rearrangements at the leading edge, increased focal adhesion maturation and cellular stiffening, which collectively promote cancer cell invasion. Shear-wave elasticity imaging of tumors from prospectively recruited patients shows that KRT80 levels correlate with stiffer tumors in vivo. Collectively, our data uncover an unpredicted and potentially targetable direct link between epigenetic and cytoskeletal reprogramming promoting cell invasion in response to chronic AI treatment. Overall design: Total RNA profiling of MCF7 breast adenocarcinoma cell line and MCF7 overexpressing KRT80. Experiments were carried out in four replicates in both cell lines.
SREBP1 drives Keratin-80-dependent cytoskeletal changes and invasive behavior in endocrine-resistant ERα breast cancer.
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View SamplesLong-term dynamic compression enhanced the mechanical properties of MSC-seeded constructs only when loading was initiated after 21 days of chondrogenic differentiation. This study examined the molecular differences of chondrogenic MSCs compared to undifferentiated MSCs (TGF-beta vs no TGF-beta) and the effects of dynamic loading on MSC chondrogenesis (loading vs free-swelling).
Long-term dynamic loading improves the mechanical properties of chondrogenic mesenchymal stem cell-laden hydrogel.
Specimen part, Disease
View SamplesSmall intestinal bacterial overgrowth (SIBO) has been implicated in symptoms associated with functional gastrointestinal disorders (FGIDs), though mechanisms remain poorly defined and treatment involves non-specific antibiotics. Here we show that SIBO based on duodenal aspirate. culture reflects an overgrowth of anaerobes, does not correspond with patient symptoms, and may be a result of dietary preferences. Small intestinal microbial composition, on the other hand, is significantly altered in symptomatic patients and does not correspond with aspirate culture results. In a pilot interventional study we found that switching from a high fiber diet to a low fiber, high simple sugar diet triggered FGID-related symptoms and decreased small-intestinal microbial diversity and small-intestinal permeability. Our findings demonstrate that characterizing small intestinal microbiomes in patients with gastrointestinal symptoms may allow a more targeted antibacterial or a diet-based approach to treatment. Overall design: A host duodenal RNA sequencing study in conjuction with a microbial analysis of small bowel aspirates following dietary intervention to reduce fiber intake for 1 week. Aspirates were collected during research endoscopy and submtttied for for 16S microbial identification (european
Small intestinal microbial dysbiosis underlies symptoms associated with functional gastrointestinal disorders.
Sex, Age, Specimen part, Disease stage, Subject, Time
View SamplesSpatial localization is a key determinant of cellular fate and behavior, but spatial RNA assays traditionally rely on staining for a limited number of RNA species. In contrast, single-cell RNA-seq allows for deep profiling of cellular gene expression, but established methods separate cells from their native spatial context. Here we present Seurat, a computational strategy to infer cellular localization by integrating single-cell RNA-seq data with in situ RNA patterns. We applied Seurat to spatially map 851 single cells from dissociated zebrafish (Danio rerio) embryos, inferring a transcriptome-wide map of spatial patterning. We confirmed Seurat’s accuracy using several experimental approaches, and used it to identify a set of archetypal expression patterns and spatial markers. Additionally, Seurat correctly localizes rare subpopulations, accurately mapping both spatially restricted and scattered groups. Seurat will be applicable to mapping cellular localization within complex patterned tissues in diverse systems. Overall design: We generated single-cell RNA-seq profiles from dissociated cells from developing zebrafish embryos (late blastula stage - 50% epiboly)
Spatial reconstruction of single-cell gene expression data.
Subject
View SamplesSMART-seq2 was performed on single cells isolated from visually staged zebrafish embryos. Overall design: Samples were all sequenced in one batch. Some were generated with a 5'' UMI-tagged method, and others are full-length SMART-seq2.
Single-cell reconstruction of developmental trajectories during zebrafish embryogenesis.
Subject
View SamplesWild-type zebrafish embryos were mechanically dissociated and profiled using Drop-seq Overall design: Drop-seq was performed on 28 groups of 20-40 visually staged, mechanically dissociated embryos. Samples were combined and sequenced in batches DS2-DS5.
Single-cell reconstruction of developmental trajectories during zebrafish embryogenesis.
Subject
View SamplesWild-type and MZoep zebrafish embryos were mechanically dissociated and profiled using 10x Genomics pipeline. Overall design: 10x scRNA-seq was performed on visually staged, mechanically dissociated embryos. Samples were combined and sequenced in one batch.
Single-cell reconstruction of developmental trajectories during zebrafish embryogenesis.
Subject
View SamplesDendritic cells (DC) arise from a diverse group of hematopoietic progenitors and have marked phenotypic and functional heterogeneity. We have found previously that activation of protein kinase C beta 2 (PRKCB2) by cytokines or phorbol esters drives normal human CD34(+) hematopoietic progenitors and myeloid leukemic blasts (KG1, K562 cell lines, and primary patient blasts) to differentiate into DC, but the genetic program triggered by PRKCB2 activation that results in DC differentiation is only beginning to be characterized. Of the cPKC isoforms, only PRKCB2 was consistently activated by DC differentiation-inducing stimuli in normal and leukemic progenitors. To examine early changes in gene expression following PRKCB2 activation, we employed the following cell lines: (1) the CD34(+) human acute myeloid leukemia derived cell line KG1, which undergoes DC differentiation following phorbol ester treatment; (2) KG1a, a spontaneously arising differentiation-resistant daughter cell line of KG1 that has lost PRKCB2 expression; (3) clones established from KG1a that stably express exogenous PRKCB2-GFP fusion proteins and are once again able to undergo DC differentiation (KG1a-PRKCB2-GFP Clone E9 and Clone E11). We examined changes in gene expression in these cells following treatment with the phorbol ester PMA (phorbol 12-myristate 13-acetate) for 2 hours. Since KG1 and KG1a differ in PRKCB2 expression but have similar expression of the other protein kinase C isoforms, this protocol will allow for the identification of genes regulated by PRKCB2 activation.
Tumor-induced STAT3 signaling in myeloid cells impairs dendritic cell generation by decreasing PKCβII abundance.
Sex, Age, Specimen part, Cell line, Treatment
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