Reactive oxygen species (ROS) are implicated in tumor transformation by modulating proteins involved in differentiation, proliferation and invasion. In order to identify genes that may support melanoma progression or regression after an antioxidant system (AOS) response, we developed and characterized a human melanoma cell model with different levels of ROS by stably overexpressing the antioxidant enzyme catalase in A375 amelanotic melanoma cells, and whole genome gene expression patterns were analyzed by microarrays.
Reprogramming human A375 amelanotic melanoma cells by catalase overexpression: Upregulation of antioxidant genes correlates with regression of melanoma malignancy and with malignant progression when downregulated.
Specimen part, Cell line
View SamplesDevelopment of systems allowing the maintenance of native properties of mesenchymal stromal cells (MSC) is a critical challenge for studying physiological functions of skeletal progenitors, as well as towards cellular therapy and regenerative medicine applications. Conventional stem cell culture in monolayer on plastic dishes (2D) is associated with progressive loss of functionality, likely due to the absence of a biomimetic microenvironment and the selection of adherent populations. Here we demonstrate that 2D MSC expansion can be entirely bypassed by culturing freshly isolated bone marrow cells within the pores of 3D scaffolds in a perfusion-based bioreactor system, followed by enzymatic digestion for cell retrieval. The 3D-perfusion system supported MSC growth while maintaining cells of the hematopoietic lineage, and thus generated a cellular environment mimicking some features of the bone marrow stroma. As compared to 2D-expansion, sorted CD45- cells derived from 3D-perfusion culture after the same time (3 weeks) or a similar extent of proliferation (7-8 doublings) maintained a 4.3-fold higher clonogenicity and exhibited a superior differentiation capacity towards all typical mesenchymal lineages, with similar immunomodulatory function in vitro. Transcriptomic analysis performed on MSC from 5 donors validated the robustness of the process and indicated a reduced inter-donor variability as well as a significant upregulation of multipotency-related gene clusters following 3D-perfusion as compared to 2D expansion. The described system offers a model to study how factors of a 3D engineered niche may regulate MSC function and, by streamlining conventional labor-intensive processes, is prone to automation and scalability within closed bioreactor systems.
Expansion of human mesenchymal stromal cells from fresh bone marrow in a 3D scaffold-based system under direct perfusion.
No sample metadata fields
View SamplesThe transcription factor NF-E2-related factor 2 (Nrf2) induces cytoprotective genes, but has also been linked to the regulation of hepatic energy metabolism. In order to assess the pharmacological potential of hepatic Nrf2 activation in metabolic disease, Nrf2 was activated over 8 weeks in mice on Western diet using two different siRNAs against kelch-like ECH-associated protein 1 (Keap1), the inhibitory protein of Nrf2. Whole genome expression analysis followed by pathway analysis demonstrated that the suppression of Keap1 expression induced genes that are involved in anti-oxidative stress defense and biotransformation, pathways proving the activation of Nrf2 by the siRNAs against Keap1. The expression of neither fatty acid- nor carbohydrate-handling proteins was regulated by the suppression of Keap1. Metabolic profiling of the animals did also not show effects on plasma and hepatic lipids, energy expenditure or glucose tolerance by the activation of Nrf2. The data indicate that hepatic Nrf2 is not a major regulator of intermediary metabolism in mice.
Chronic Activation of Hepatic Nrf2 Has No Major Effect on Fatty Acid and Glucose Metabolism in Adult Mice.
Specimen part, Treatment
View SamplesAge-related frailty may in part be due to a decreased competency in skeletal muscle regeneration. The role of the closely related TGFbeta amily molecules myostatin and GDF11 in regeneration is unclear. The commercially available antibody which in a prior report was used to demonstrate an age-related decrease in GDF11 was found to detect both GDF11 and myostatin, and with this reagent it appears that the combination of GDF11 and myostatin increases with age in serum. Mechanistically, GDF11 and myostatin induce SMAD2/3 phosphorylation, and both inhibit myoblast differentiation and regulate identical downstream signaling. GDF11 injected into adult mice in a model of regeneration induces an increase in smaller fibers and a decrease in satellite cell expansion. There are no signs of benefit from GDF11 to regeneration. Thus, GDF11 appears to be an age-associated myokine that inhibits muscle differentiation, and is thus a target for blockade to treat frailty
GDF11 Increases with Age and Inhibits Skeletal Muscle Regeneration.
Treatment, Time
View SamplesUtilizing glycerol and cardiotoxin (CTX) injections in the tibialis anterior muscles of M. musculus provides models of skeletal muscle damages followed by skeletal muscle regeneration. In particular, glycerol-induced muscle regeneration is known to be associated with ectopic adipogenesis. We characterized genome-wide expression profiles of tibialis anterior muscles from wild-type mice injured by either glycerol or CTX injection. Our goal was to detect gene expression changes during the time course of glycerol-induced and CTX-induced muscle regeneration models, that can lead to ectopic adipocyte accumulation.
Genomic profiling reveals that transient adipogenic activation is a hallmark of mouse models of skeletal muscle regeneration.
Sex, Age, Specimen part
View SamplesThe Polycomb group (PcG) proteins form chromatin-modifying complexes that are essential for embryonic development and stem cell renewal and are commonly deregulated in cancer. Here, we identify their target genes using genome-wide location analysis in human embryonic fibroblasts. We find that Polycomb-Repressive Complex 1 (PRC1), PRC2, and tri-methylated histone H3K27 co-occupy >1000 silenced genes with a strong functional bias for embryonic development and cell fate decisions. We functionally identify 40 genes derepressed in human embryonic fibroblasts depleted of the PRC2 components (EZH2, EED, SUZ12) and the PRC1 component, BMI-1. Interestingly, several markers of osteogenesis, adipogenesis, and chrondrogenesis are among these genes, consistent with the mesenchymal origin of fibroblasts. Using a neuronal model of differentiation, we delineate two different mechanisms for regulating PcG target genes. For genes activated during differentiation, PcGs are displaced. However, for genes repressed during differentiation, we paradoxically find that they are already bound by the PcGs in nondifferentiated cells despite being actively transcribed. Our results are consistent with the hypothesis that PcGs are part of a preprogrammed memory system established during embryogenesis marking certain key genes for repressive signals during subsequent developmental and differentiation processes.
Genome-wide mapping of Polycomb target genes unravels their roles in cell fate transitions.
No sample metadata fields
View SamplesTranscriptome profiling using RNA-seq of MV+, a mouse lens epithelium cell line expressing Pax6 and RAG renal adenocarcinoma cell line which does not express Pax6. Overall design: Total RNA was collected and a Illumina sequencing libraries prepared from three biological replicates of cultured MV+ and RAG cells.
Polymer Simulations of Heteromorphic Chromatin Predict the 3D Folding of Complex Genomic Loci.
Cell line, Subject
View SamplesPolycomb group (PcG) proteins form multiprotein complexes, called Polycomb repressive complexes (PRCs). PRC2 contains the PcG proteins EZH2, SUZ12, and EED and represses transcription through methylation of lysine (K) 27 of histone H3 (H3). Suz12 is essential for PRC2 activity and its inactivation results in early lethality of mouse embryos.
The polycomb group protein Suz12 is required for embryonic stem cell differentiation.
Specimen part
View SamplesUnderstanding the molecular underpinnings of chemoresistance is vital to design therapies to restore chemosensitivity. In particular, metadherin (MTDH) has been demonstrated to have a critical role in chemoresistance. Over-expression of MTDH has recently been implicated in poor clinical outcome in breast cancer, neroblastoma, hepatocellular carcinoma and prostate cancer. In this present study, we focused on the therapeutic benefit of MTDH depletion to restore sensitivity to cell death mediated by a combinatorial therapy of tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL), which promotes death of cancerous cells of the human reproductive tract, and histone deacetylase (HDAC) inhibitors, which have been shown to increase sensitivity of cancer cells to TRAIL-induced apoptosis. Our data indicate that depletion of MTDH in endometrial cancer cells results in sensitization of cells that were previously resistant to cell death mediated by combinatorial treatment with TRAIL and HDAC inhibitor LBH589. MTDH was found to be involved in G2/M checkpoint regulation in response to LBH589 alone or LBH589 in combination with TRAIL, suggesting that MTDH functions at the cell cycle checkpoint to accomplish resistance.Using microarray technology, we identified 57 downstream target genes of MTDH, including Calbindin 1 and Galectin 1, which may contribute to MTDH-mediated resistance to combinatorial TRAIL and HDAC inhibitor targeted therapy. Inhibition of PDK1,AKT phosphorylation and increase Bim expression and XIAP degradation may result in sensitivity to cell death induction in MTDH depleted Hec50co cells by TRAIL and LBH 589 combination treatment. These findings indicate that depletion of MTDH is a potentially novel avenue for effective cancer therapy.
Knockdown of MTDH sensitizes endometrial cancer cells to cell death induction by death receptor ligand TRAIL and HDAC inhibitor LBH589 co-treatment.
Disease, Disease stage, Cell line
View SamplesUnderstanding the molecular underpinnings of chemoresistance is vital to design therapies to restore chemosensitivity. In particular, metadherin (MTDH) has been demonstrated to have a critical role in chemoresistance. Over-expression of MTDH has recently been implicated in poor clinical outcome in breast cancer, neroblastoma, hepatocellular carcinoma and prostate cancer. In this present study, we focused on the therapeutic benefit of MTDH depletion to restore sensitivity to cell death mediated by a combinatorial therapy of tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL), which promotes death of cancerous cells of the human reproductive tract, and histone deacetylase (HDAC) inhibitors, which have been shown to increase sensitivity of cancer cells to TRAIL-induced apoptosis. Our data indicate that depletion of MTDH in endometrial cancer cells results in sensitization of cells that were previously resistant to cell death mediated by combinatorial treatment with TRAIL and HDAC inhibitor LBH589. MTDH was found to be involved in G2/M checkpoint regulation in response to LBH589 alone or LBH589 in combination with TRAIL, suggesting that MTDH functions at the cell cycle checkpoint to accomplish resistance.Using microarray technology, we identified 57 downstream target genes of MTDH, including Calbindin 1 and Galectin 1, which may contribute to MTDH-mediated resistance to combinatorial TRAIL and HDAC inhibitor targeted therapy. Inhibition of PDK1,AKT phosphorylation and increase Bim expression and XIAP degradation may result in sensitivity to cell death induction in MTDH depleted Hec50co cells by TRAIL and LBH 589 combination treatment. These findings indicate that depletion of MTDH is a potentially novel avenue for effective cancer therapy.
Knockdown of MTDH sensitizes endometrial cancer cells to cell death induction by death receptor ligand TRAIL and HDAC inhibitor LBH589 co-treatment.
Specimen part, Cell line
View Samples