Despite advances in investigating functional aspects of osteoblast (OB) differentiation, especially studies on how bone proteins are deposited and mineralized, there has been little research on the intracellular trafficking of bone proteins during OB differentiation. Collagen synthesis and secretion is markedly upregulated upon Ascorbic Acid (AA) stimulation. Understanding the mechanism by which collagen is mobilized in specialized OB cells is important for both basic cell biology and diseases involving defects in bone secretion and deposition. RabGTPases are major regulators on protein trafficking throughout the cell. In this study, we identified the Rab GTPases that are upregulated during 5-day AA differentiation of OBs using microarray analysis, namely Rab1, Rab3d and Rab27b.
Rab GTPase mediated procollagen trafficking in ascorbic acid stimulated osteoblasts.
Specimen part, Cell line
View SamplesWhether the human tumor virus, Epstein-Barr virus (EBV) promotes breast cancers remains controversial and a potential mechanism has remained elusive. Here we show EBV can infect primary mammary epithelial cells (MECs) that express the attachment receptor, CD21. EBV infection leads to the expansion of early MEC progenitor cells with a stem cell phenotype and enforces a differentiation block. When MECs were implanted as xenografts, EBV infection cooperated with activated Ras and accelerated the formation of breast cancer. Infection in EBV-related tumors was of a latency type II pattern, including expression of latent membrane proteins 1 (LMP1) and 2 (LMP2), similar to nasopharyngeal carcinoma (NPC). A human gene expression signature for EBVness was generated based on the RNA expression profile of the EBV infected primary mammary epithelial cells, tumors. This was signature associated with high grade (40 vs 13.5%) estrogen-receptor-negative status (31.8 vs. 10.5%, p53 mutation (37.5 vs 14.5%) and poor survival. In 11/33 (33%) of tumors positive for EBVness EBV-DNA was found in tumor cells by fluorescent in situ hybridization for the viral LMP1 and BXLF2 genes, while only 4/36 (11%) of EBVness-negative tumors tested positive for EBV DNA. An analysis of the TCGA breast cancer data revealed a correlation of EBVness with presence of the APOBEC mutational signatures consistent with past viral infection. We conclude that a contribution of EBV to breast cancer etiology via a hit-and-run mechanism is plausible, in which EBV infection predisposes mammary epithelial cells to malignant transformation, but is not required for the maintenance of the malignant phenotype.
Epstein-Barr Virus Infection of Mammary Epithelial Cells Promotes Malignant Transformation.
Specimen part, Cell line
View SamplesDilated cardiomyopathy (DCM) is a common cause of heart failure and a leading cause of cardiac transplantation in western countries. The robust predictive expression profile of cardiomyopathic and NF hearts as well as the functional classification can help to identify promising candidates for DCM and may improve the early diagnosis of cardiomyopathy.
Identification of a common gene expression signature in dilated cardiomyopathy across independent microarray studies.
No sample metadata fields
View SamplesGSE2240 contains two different experimental subsets:
Functional profiling of human atrial and ventricular gene expression.
No sample metadata fields
View SamplesCell body and pseudopod RNA are differentially regulated during the migration of the metastatic cancer cells.We wanted to identify the RNA which are upregulated in the pseudopodial (PS) fraction as compared to cell body fraction (CB).
Pseudopodial actin dynamics control epithelial-mesenchymal transition in metastatic cancer cells.
Cell line
View SamplesWe used a whole genome approach to identify major functional gene categories (including xenobiotic transporters and metabolizing enzymes) whose expression depends on gestational age. STUDY DESIGN: We compared gene expression profiles of 1st (45-59 days) and 2nd trimester (109-115 days), and C-section term placentae. RESULTS: In 1st trimester placentae, genes related to cell cycle, DNA, aminoacids and carbohydrate metabolism were significantly overrepresented, while genes related to signal transduction were downregulated. In the organism defense category, we identified genes involved in chemical response, metabolism, and transport. Analysis of signal transduction pathways suggested, and subsequently confirmed independently, that the Wnt pathway was regulated by gestational age. CONCLUSIONS: Our study will serve as a reference database to gain insight into the regulation of gene expression in the developing placentae and, thus, allow comparisons with placentae from complicated pregnancies such as those in women experiencing gestational diabetes, pre-eclampsia and teratogenic sequelae.
Profiling gene expression in human placentae of different gestational ages: an OPRU Network and UW SCOR Study.
No sample metadata fields
View SamplesExon usage analysis in in vitro cultured fibroblast cells. To assay the genome-wide splicing changes during cellular senescence, we performed splicing analysis on young and old normal fibroblasts, and in fibroblasts +/- tert (telomerase protein subunit Tert immortalized).
Progerin and telomere dysfunction collaborate to trigger cellular senescence in normal human fibroblasts.
Specimen part, Disease, Disease stage, Subject
View SamplesCanonical Wnt signalling regulates the self-renewal of most if not all stem cell systems. In the blood system, the role of Wnt signalling has been subject of much debate, with positive and negative roles of Wnt signalling proposed for hematopoietic stem cells (HSC). As we have shown previously, this controversy can be largely explained by the effects of different dosages of Wnt signalling. What remained unclear however, was why high Wnt signals would lead to loss of reconstituting capacity. To better understand this phenomenon, we have taken advantage of a series of hypomorphic mutant Apc alleles resulting in a broad range of Wnt dosages in HSCs, purified those HSCs and performed whole genome gene expression analyses. Gene expression profiling and functional studies show that HSCs with APC mutations lead to high Wnt levels , enhanced differentiation and diminished proliferation, but have no effect on apoptosis, collectively leading to loss of stemness. Thus, we provide mechanistic insight into the role of APC mutations and Wnt signalling in HSC biology. As Wnt signals are explored in various in vivo and ex vivo expansion protocols for HSCs, our findings also have clinical ramifications.
High Levels of Canonical Wnt Signaling Lead to Loss of Stemness and Increased Differentiation in Hematopoietic Stem Cells.
No sample metadata fields
View SamplesDendritic cells (DCs) are crucial for sensing pathogens and triggering immune response. GM-CSF myeloid dendritic cells (GM-DCs) secrete several cytokines including IL-2 upon activation by pathogen associated molecular pattern (PAMP) ligands. DC IL-2 has been shown to be important for innate and adaptive immune responses, however its importance in DC physiology has never been demonstrated. This is due to ambiguity in expression of the CD122 subunit of the IL-2 trimeric receptor complex crucial for signaling. We show here that autocrine IL-2 signaling is functional in GM-DCs in early time window of stimulation with PAMPs. IL-2 signaling selectively activates the JAK/STAT5 pathway by assembling holo-receptor complexs at the cell surface. Autocrine IL-2 signaling inhibits survival of PAMP matured GM-DCs which is crucial for maintaining immune tolerance and preventing autoimmunity. Our findings suggest immune regulation by a novel autocrine signaling pathway that can potentially be exploited in DC immunotherapy.
Dendritic cell derived IL-2 inhibits survival of terminally mature cells via an autocrine signaling pathway.
Specimen part
View SamplesTranscriptome analysis on ING5-knockdown brain tumor stem cell lines
ING5 activity in self-renewal of glioblastoma stem cells via calcium and follicle stimulating hormone pathways.
Specimen part, Cell line
View Samples