Here we show that the histone methyltransferase MLL4 (Kmt2d) is required for stem cell activity and an aggressive form of acute myeloid leukemia (AML) harboring the MLL-AF9 oncogene. MLL4 exerts its function by regulating transcriptional programs associated with the anti-oxidant response. Overall design: The role of Mll4 (Kmt2d) in regulating the transcriptome of primary and transformed hematopoietic stem cells was studied.
DNA-damage-induced differentiation of leukaemic cells as an anti-cancer barrier.
No sample metadata fields
View SamplesGene expression in HeLa cells was profiled using Affymetrix gene expression Human HG-U133_Plus_2 array. Transcript signal was mapped against the chromosome coordinates (probe-by-probe basis) using the HG-U133A_2 Annotations CSV file for hg18 build of the human genome provided by Affymetrix.
Genomic study of replication initiation in human chromosomes reveals the influence of transcription regulation and chromatin structure on origin selection.
Cell line
View SamplesThe innate repair and regeneration potential of skeletal tissues such as the intervertebral disc and articular cartilage is extremely limited, in part due to their avascularity and low cell density. Despite recent advances in MSC-based disc and cartilage regeneration, key challenges remain, including the sensitivity of these cells to in vivo microenvironmental stress such as low oxygen and nutrient levels. The objective of this study was to investigate whether preconditioning with hypoxia and/or transforming growth factor-beta (TGF-) can enhance MSC survival and extracellular matrix production in a low oxygen and nutrient-limited microenvironment. Secondarily, the effects of donor variability on the response of MSCs to preconditioning was examined. MSCs from multiple bovine donors were preconditioned in monolayer in normoxia or hypoxia, with or without TGF-.
Hypoxic Preconditioning Enhances Bone Marrow-Derived Mesenchymal Stem Cell Survival in a Low Oxygen and Nutrient-Limited 3D Microenvironment.
Specimen part
View SamplesMice were immunized with PCC (pigeon cytochrome c).
Lymphoid reservoirs of antigen-specific memory T helper cells.
No sample metadata fields
View SamplesThe mRNA processing body is a cellular structure that regulates the stability of cytoplasmic mRNA. MARF1/LMKB is an RNA-binding protein that is associated with maintenance of mRNA homeostasis and genomic stability. To investigate the function of LMKB in a human B lymphocyte cell line, BJAB cells were treated with either control lentivirus or a lentivirus containing LMKB siRNA.
LMKB/MARF1 localizes to mRNA processing bodies, interacts with Ge-1, and regulates IFI44L gene expression.
Specimen part, Cell line
View SamplesThere is increasing evidence that breast and other cancers originate from and are maintained by a small fraction of stem/progenitor cells with self-renewal properties. Whether such cancer stem/progenitor cells originate from normal stem cells based on initiation of a de novo stem cell program, by reprogramming of a more differentiated cell type by oncogenic insults or both remains unresolved. A major hurdle in addressing these issues is lack of immortal human stem/progenitor cells that can be deliberately manipulated in vitro. We present evidence that normal and human telomerase reverse transcriptase (hTERT)-immortalized human mammary epithelial cells (hMECs) isolated and maintained in DFCI-1 medium retain a fraction with progenitor cell properties. These cells co-express basal, luminal and stem/progenitor cell markers. Clonal derivatives of progenitors co-expressing these markers fall into two distinct types: K5+/K19- (Type I) and K5+/K19+ (Type II). We show that both types of progenitor cells have self-renewal and differentiation ability. Through microarray analysis, we want to identify genes and pathways linked to human mammary epithelial stem/progenitor cell self-renewal and differentiation.
Telomerase-immortalized human mammary stem/progenitor cells with ability to self-renew and differentiate.
Sex, Specimen part
View SamplesMicroRNAs (miRNAs) have been globally profiled in cancers but there tends to be poor agreement between studies including in the same cancers. Additionally, few putative miRNA targets have been validated. To overcome the lack of reproducibility, we profiled miRNAs by next generation sequencing and locked nucleic acid miRNA microarrays, and we verified concordant changes by quantitative RT-PCR. Notably, miR-125b and the miR-99 family members miR-99a, -99b, -100 were down-regulated in all assays in advanced prostate cancer cell lines relative to the parental cell lines from which they were derived. All four miRNAs were also down-regulated in human prostate tumor tissue compared to normal prostate. Transfection of miR-99a, -99b or -100 inhibited the growth of prostate cancer cells and decreased the expression of prostate-specific antigen (PSA), suggesting potential roles as tumor suppressors in this setting. To identify targets of these miRNAs, we combined computational prediction of potential targets with experimental validation by microarray and polyribosomal loading analysis. Three direct targets of the miR-99 family that were validated in this manner were the chromatin remodeling factors SMARCA5 and SMARCD1 and the growth regulatory kinase mTOR. We determined that PSA is post-transcriptionally regulated by the miR-99 family members at least partially by repression of SMARCA5. Together, our findings suggest key functions and targets of miR-99 family members in prostate cancer suppression and prognosis.
miR-99 family of MicroRNAs suppresses the expression of prostate-specific antigen and prostate cancer cell proliferation.
Specimen part, Cell line
View SamplesIre1 conditional null or control mice of 3-months old were injected intraperitoneally with TM or vehicle.
The unfolded protein response transducer IRE1α prevents ER stress-induced hepatic steatosis.
Specimen part
View SamplesWe aimed to identify specific biomarkers of IFN-beta bioactivity in order to compare their gene expression induction by type I IFNs with the MxA, and to investigate their potential role in MS pathogenesis. Gene expression microarrays were performed in PBMC from MS patients who developed neutralizing antibodies (NAB) to IFN-beta. Nine genes followed patterns in gene expression over time similar to the MX1 and were selected for further experiments: IFI6, IFI27, IFI44L, IFIT1, HERC5, LY6E, RSAD2, SIGLEC1, and USP18. In vitro experiments revealed specific induction of selected biomarkers by IFN-beta but not IFN-gamma, and several markers, in particular USP18 and HERC5, were significantly induced at lower IFN-beta concentrations and more selective than the MX1 as biomarkers of IFN-beta bioactivity. In addition, USP18 expression was deficient in MS patients compared with healthy controls (p=0.0004). We propose specific biomarkers that may be considered in addition to the MxA to evaluate IFN-beta bioactivity, and to further explore their implication in MS pathogenesis.
Search for specific biomarkers of IFNβ bioactivity in patients with multiple sclerosis.
Sex, Age, Specimen part, Disease, Disease stage, Treatment, Subject, Time
View SamplesThe lack of mouse models permitting the specific ablation of tissue-resident macrophages and monocyte-derived cells complicates understanding of their contribution to tissue integrity and to immune responses. Here we use a new model permitting diphtheria-toxin (DT)-mediated depletion of those cells and in which dendritic cells are spared. We showed that the myeloid cells of the mouse ear skin dermis are dominated by a population of melanin-laden macrophages, called melanophages, that has been missed in most previous studies. By using gene expression profiling, DT-mediated ablation and parabiosis, we determined their identity including their similarity to other skin macrophages, their origin and their dynamics. Limited information exist on the identity of the skin cells responsible for long-term tattoo persistence. Benefiting of our knowledge on melanophages, we showed that they are responsible for retaining tattoo pigment particles through a dynamic process which characterization has direct implications for improving strategies aiming at removing tattoos.
Unveiling skin macrophage dynamics explains both tattoo persistence and strenuous removal.
Specimen part, Treatment
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