The objective of this study was to reprogram peripheral blood-derived late-endothelial progenitor cells (EPCs) to a pluripotent state under feeder-free and defined culture conditions. Late-EPCs were retrovirally-transduced with OCT4, SOX2, KLF4, c-MYC, and iPSC colonies were derived in feeder-free and defined media conditions. EPC-iPSCs expressed pluripotent markers, were capable of differentiating to cells from all three germ-layers, and retained a normal karyotype. Transcriptome analyses demonstrated that EPC-iPSCs exhibit a global gene expression profile similar to human embryonic stem cells (hESCs). We have generated iPSCs from late-EPCs under feeder-free conditions. Thus, peripheral blood-derived late-outgrowth EPCs represent an alternative cell source for generating iPSCs.
Feeder-independent derivation of induced-pluripotent stem cells from peripheral blood endothelial progenitor cells.
Specimen part, Cell line
View SamplesMonoclonal antibodies (mAbs) targeting the oncogenic receptor tyrosine kinase ERBB2/HER2, such as Trastuzumab, are the standard of care therapy for breast cancers driven by ERBB2 overexpression and activation. However, a substantial proportion of patients exhibits de novo resistance. Here, by comparing matched Trastuzumab-naïve and post-treatment patient samples from a neoadjuvant trial, we link resistance with elevation of H3K27me3, a repressive histone modification catalyzed by Polycomb Repressor Complex 2 (PRC2). In ErbB2+ breast cancer models, PRC2 silences endogenous retroviruses (ERVs) to suppress anti-tumor Type-I interferon (IFN) responses. In patients, elevated H3K27me3 in tumor cells following Trastuzumab treatment correlates with suppression of IFN-driven viral defense gene expression signatures and poor response. Using an immunocompetent model, we provide evidence that EZH2 inhibitors promote IFN-driven immune responses that enhance the efficacy of anti-ErbB2 mAbs, suggesting the potential clinical benefit of epigenomic reprogramming by H3K27me3 depletion in Trastuzumab-resistant disease.
Reduction of Global H3K27me<sup>3</sup> Enhances HER2/ErbB2 Targeted Therapy.
Sex, Specimen part, Treatment
View SamplesThe hippocampus is part of a brain network essential for memory function. Paradoxically, the hippocampus is also the brain structure that is most sensitive to hypoxic-ischemic episodes. Here we show that the expression of genes associated with glycolysis and glutamate metabolism in astrocytes and the coverage of excitatory synapses by astrocytic processes undergo significant decreases in the CA1 field of the monkey hippocampus during postnatal development. Given the established role of astrocytes in the regulation of glutamate concentration in the synaptic cleft, our findings indicate that a developmental decrease in astrocytic processes underlies the selective vulnerability of CA1 during hypoxic-ischemic episodes in adulthood, its decreased susceptibility to febrile seizures with age, as well as contribute to the emergence of selective, adult-like memory function.
Developmental regulation of gene expression and astrocytic processes may explain selective hippocampal vulnerability.
Specimen part
View SamplesDue to their somatic cell origin, human induced pluripotent stem cells (HiPSCs) are assumed to carry a normal diploid genome, and adaptive chromosomal aberrations have not been fully evaluated. Here, we analyzed the chromosomal integrity of 66 HiPSC and 38 human embryonic stem cell (HESC) samples from 18 different studies by global gene expression meta-analysis. We report identification of a substantial number of cell lines carrying full and partial chromosomal aberrations, half of which were validated at the DNA level. Several aberrations resulted from culture adaptation, and others are suspected to originate from the parent somatic cell. Our classification revealed a third type of aneuploidy already evident in early passage HiPSCs, suggesting considerable selective pressure during the reprogramming process. The analysis indicated high incidence of chromosome 12 duplications, resulting in significant enrichment for cell cycle related genes. Such aneuploidy may limit the differentiation capacity and increase the tumorigenicity of HiPSCs.
Identification and classification of chromosomal aberrations in human induced pluripotent stem cells.
Specimen part, Cell line
View SamplesDue to their somatic cell origin, human induced pluripotent stem cells (HiPSCs) are assumed to carry a normal diploid genome, and adaptive chromosomal aberrations have not been fully evaluated. Here, we analyzed the chromosomal integrity of 66 HiPSC and 38 human embryonic stem cell (HESC) samples from 18 different studies by global gene expression meta-analysis. We report identification of a substantial number of cell lines carrying full and partial chromosomal aberrations, half of which were validated at the DNA level. Several aberrations resulted from culture adaptation, and others are suspected to originate from the parent somatic cell. Our classification revealed a third type of aneuploidy already evident in early passage HiPSCs, suggesting considerable selective pressure during the reprogramming process. The analysis indicated high incidence of chromosome 12 duplications, resulting in significant enrichment for cell cycle related genes. Such aneuploidy may limit the differentiation capacity and increase the tumorigenicity of HiPSCs.
Identification and classification of chromosomal aberrations in human induced pluripotent stem cells.
Specimen part, Cell line
View SamplesDue to their somatic cell origin, human induced pluripotent stem cells (HiPSCs) are assumed to carry a normal diploid genome, and adaptive chromosomal aberrations have not been fully evaluated. Here, we analyzed the chromosomal integrity of 66 HiPSC and 38 human embryonic stem cell (HESC) samples from 18 different studies by global gene expression meta-analysis. We report identification of a substantial number of cell lines carrying full and partial chromosomal aberrations, half of which were validated at the DNA level. Several aberrations resulted from culture adaptation, and others are suspected to originate from the parent somatic cell. Our classification revealed a third type of aneuploidy already evident in early passage HiPSCs, suggesting considerable selective pressure during the reprogramming process. The analysis indicated high incidence of chromosome 12 duplications, resulting in significant enrichment for cell cycle related genes. Such aneuploidy may limit the differentiation capacity and increase the tumorigenicity of HiPSCs.
Identification and classification of chromosomal aberrations in human induced pluripotent stem cells.
Specimen part, Cell line
View SamplesLimbal vs. corneal epithelial basal cell gene expression patterns were identified and compared
Transcriptional profiling of enriched populations of stem cells versus transient amplifying cells. A comparison of limbal and corneal epithelial basal cells.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Transcription factor TLX1 controls retinoic acid signaling to ensure spleen development.
Specimen part
View SamplesThe molecular mechanisms underlying asplenia, a condition often associated with overwhelming infections remain largely unknown. During spleen development, the transcription factor TLX1 controls morphogenesis and organ expansion, and loss of it causes spleen agenesis. However, the downstream signaling pathways that are deregulated in the absence of TLX1 are mostly unknown. Herein, we demonstrate that loss of Tlx1 in the splenic mesenchyme causes increased retinoic acid (RA) signaling. Increased RA activity causes premature differentiation of the splenic mesenchyme and reduced vasculogenesis of the splenic anlage. Moreover, excess or deficiency in RA signaling, as observed in Cyp26b1 or Rdh10 mutants respectively, also results in spleen growth arrest. Genome-wide analysis revealed that TLX1 binds RA-associated genes through the AP-1 site and cooperates with the AP-1 family transcription factors to regulate transcription. Pharmacological inhibition of RA signaling partially rescues the spleen defect. These findings establish the critical role of TLX1 in controlling RA metabolism, and provide novel mechanistic insights into the molecular determinants underlying congenital asplenia.
Transcription factor TLX1 controls retinoic acid signaling to ensure spleen development.
Specimen part
View SamplesMonocytes play a critical role during infection with Mycobacterium tuberculosis (Mtb). They are recruited to the lung where they participate in the contention of infection. Alternatively, inflammatory monocytes may help in prolonging inflammation or serve as niches for Mtb infection. Also, monocyte response to infection may vary depending on the particularities of the clinical isolate of Mtb from which they are infected. In this pilot study, using microarrays we have examined the global mRNA profiles of circulating human monocytes from healthy individuals and patients with active tuberculosis (TB).
Infection of Monocytes From Tuberculosis Patients With Two Virulent Clinical Isolates of <i>Mycobacterium tuberculosis</i> Induces Alterations in Myeloid Effector Functions.
Specimen part, Disease, Disease stage
View Samples