Two nuclear 5'-3' exonucleases XRN2/3 in Arabidopsis thaliana are homologs of the yeast and human Rat1/Xrn2, which are involved in degradation and processing of several classes of nuclear RNAs and in transcription termination of RNA polymerase II. Here we show that knockdown of XRN3 leads to altered expression of several hundred of the Arabidopsis genes and accumulation of new non-coding RNAs. Using strand-specific short read sequencing we reveal a widespread accumulation of intergenic transcripts in xrn3 mutants. These non-coding XAT (xrn3-associated transcripts) RNAs are generated by Pol II read-through transcription and are usually polyadenylated and lack the 5' cap structure. We show that XRN3-mediated changes in expression of a subset of genes are related to XAT transcription and may be enhanced by XAT-mRNA chimeras produced in xrn3 plants while antisense XATs may trigger siRNA production. Our results highlight the important role of the Rat1/Xrn2 5'-3' exoribonucleases in the torpedo mechanism of Pol II transcription termination and show that a global disturbance in this process significantly impacts both gene expression and transcriptome integrity.
Defective XRN3-mediated transcription termination in Arabidopsis affects the expression of protein-coding genes.
Age, Specimen part, Time
View SamplesProspective isolation is critical to understand the cellular and molecular aspects of stem cell heterogeneity. Here we identify the cell surface antigen CD9 as a novel positive marker that provides a simple alternative for hematopoietic stem cell-isolation at high purity Overall design: mRNA profiles of LT and ST HSCs
The tetraspanin CD9 affords high-purity capture of all murine hematopoietic stem cells.
Subject
View SamplesTo discover novel growth factors for hematopoietic stem- and progenitor cells (HSPCs), we have assessed cytokine responses of cord blood (CB)-derived CD34+ cells in a high-content growth factor screen. We identify the immunoregulatory chemokine (C-C motif) ligand 28 (CCL28) as a novel growth factor that directly stimulates proliferation of primitive hematopoietic cells from different ontogenetic origins.
Identification of the chemokine CCL28 as a growth and survival factor for human hematopoietic stem and progenitor cells.
Specimen part
View SamplesBackground: Global gene expression profiling has been widely used in lung cancer research to identify clinically relevant molecular subtypes as well as to predict prognosis and therapy response. So far, the value of these multi-gene signatures in clinical practice is unclear and the biological importance of individual genes is difficult to assess as the published signatures virtually do not overlap.
Biomarker discovery in non-small cell lung cancer: integrating gene expression profiling, meta-analysis, and tissue microarray validation.
Sex, Age
View SamplesTK2 deficiency causes severe mtDNA depeltion in several tissues, including skeletal muscle and heart. TK2 knockout mice grow slower and their skeletal muscles appeared significantly underdeveloped, whereas heart was close to normal size.
Gene expression deregulation in postnatal skeletal muscle of TK2 deficient mice reveals a lower pool of proliferating myogenic progenitor cells.
Age, Specimen part
View SamplesParathyroid hormone (PTH) plays an essential role in regulating calcium and bone homeostasis in the adult, but whether PTH is required at all for regulating fetal-placental mineral homeostasis is uncertain. To address this we treated Pth-null mice in utero with 1 nmol PTH (1-84) or saline and examined placental calcium transfer 90 minutes later. It was found that placental calcium transfer increased in Pth-null fetuses treated with PTH as compared to Pth-null fetuses treated with saline. Subsequently, to determine the effect of PTH treatment on placental gene expression, in a separate experiment, 90 minutes after the fetal injections the placentas were removed for subsequent RNA extraction and microarray analysis.
Parathyroid hormone regulates fetal-placental mineral homeostasis.
Sex, Specimen part, Treatment
View SamplesProthrombin (PT) and osteopontin (OPN) promotes adhesion of different TRAP-positive multinucleated cells isolated from rat long bone (Hu et al. Exp Cell Res. 2008; 314: 638-50). The PT-adhering cell could represent either an immature precursor to the OPN-adherent osteoclast or constitute a distinct multinucleated cell population with a unique role in bone. Herein, phenotypic differences between PT- and OPN- cells were investigated with microarray- expression analysis. Characteristic for PT-cells was expression of innate immune response genes and scavenger receptors whereas OPN-cells expressed typical osteoclast proteins such as collagenases implicated in bone degradation.
Isolation and phenotypic characterization of a multinucleated tartrate-resistant acid phosphatase-positive bone marrow macrophage.
Specimen part
View SamplesMicroarray based mRNA profiling was used to charactarize and compare the gene expression in cells grown as monolayer or spheroids.
Loss of cancer drug activity in colon cancer HCT-116 cells during spheroid formation in a new 3-D spheroid cell culture system.
Cell line
View SamplesA sensitive assay to identify biomarkers that can accurately diagnose the onset of breast cancer using non-invasively collected clinical specimens is ideal for early detection. In this study, we have conducted a prospective sample collection and retrospective blinded validation (PRoBE design) to evaluate the performance and translational utilities of salivary transcriptomic and proteomic biomarkers for the non-invasive detection of breast cancer. The Affymetrix HG U133 Plus 2.0 Array and 2D-DIGE were used to profile transcriptomes and proteomes in saliva supernatants respectively. Significant variations of salivary transcriptomic and proteomic profiles were observed between breast cancer patients and healthy controls. Eleven transcriptomic biomarker candidates and two proteomic biomarker candidates were selected for a preclinical validation using an independent sample set. Transcriptomic biomarkers were validated by RT-qPCR and proteomic biomarkers were validated by quantitative protein immunoblot. Eight mRNA biomarkers and one protein biomarker have been validated for breast cancer detection, yielding ROC-plot AUC values between 0.665 and 0.959. This report provides proof of concept of salivary biomarkers for the non-invasive detection of breast cancer. The salivary biomarkers discriminatory power paves the way for a PRoBE-design definitive validation study.
Discovery and preclinical validation of salivary transcriptomic and proteomic biomarkers for the non-invasive detection of breast cancer.
Disease
View SamplesAutologous chondrocyte transplantation (ACT) is a routine technique to regenerate focal cartilage lesions. However, patients with osteoarthritis (OA) are lacking an appropriate long-lasting treatment alternative, partly since it is not known if chondrocytes from OA patients have the same chondrogenic differentiation potential as chondrocytes from donors not affected by OA. Articular chondrocytes from patients with OA undergoing total knee replacement (Mankin Score >3, Ahlbck Score >2) and from patients undergoing ACT, here referred to as normal donors (ND), were isolated applying protocols used for ACT. Their chondrogenic differentiation potential was evaluated both in high-density pellet and scaffold (Hyaff-11) cultures by histological proteoglycan assessment (Bern Score) and immunohistochemistry for collagen types I and II. Chondrocytes cultured in monolayer and scaffolds were subjected to gene expression profiling using genome-wide oligonucleotide microarrays. Expression data were verified by using quantitative RT-PCR. Chondrocytes from ND and OA donors demonstrated accumulation of comparable amounts of cartilage matrix components, including sulphated proteoglycans and collagen types I and II. The mRNA expression of cartilage markers (COL2A1, COMP, aggrecan, CRTL1, SOX9) and genes involved in matrix synthesis (biglycan, COL9A2, COL11A1, TIMP4, CILP2) was highly induced in 3D cultures of chondrocytes from both donor groups. Genes associated with hypertrophic or OA cartilage (COL10A1, RUNX2, periostin, ALP, PTHR1, MMP13, COL1A1, COL3A1) were not significantly regulated between the two groups of donors. The expression of 661 genes, including COMP, FN1, and SOX9, were differentially regulated between OA and ND chondrocytes cultured in monolayer. During scaffold culture, the differences diminished between the OA and ND chondrocytes, and only 184 genes were differentially regulated. Only few genes were differentially expressed between OA and ND chondrocytes in Hyaff-11 culture. The risk of differentiation into hypertrophic cartilage does not seem to be increased for OA chondrocytes. Our findings suggest that the chondrogenic capacity is not significantly affected by OA and OA chondrocytes fulfill the requirements for matrix-associated ACT.
Chondrogenic differentiation potential of osteoarthritic chondrocytes and their possible use in matrix-associated autologous chondrocyte transplantation.
Specimen part
View Samples