Keeping imbibed seeds at low temperatures for a certain period, so called seed vernalization (SV) treatment, promotes seed germination and subsequent flowering in various plants. Vernalization-promoting flowering requires GSH. However, the expression patterns analyzed by GeneChip arrays showed that increased GSH biosynthesis partially mimics SV treatment in Arabidopsis thaliana. SV treatment (keeping imbibed seeds at 4C for 24 h) induced a specific pattern of gene expression and promoted subsequent flowering in wild-type plants. A similar pattern was observed at 22C in transgenic plants (35S-GSH1 plants) overexpressing the -glutamylcysteine synthetase gene GSH1, coding an enzyme limiting GSH biosynthesis, under the control of the cauliflower mosaic virus 35S promoter. This pattern was strengthened at 4C but flowering was less responsive to SV treatment. There was a difference in the transcript behaviour of the flowering repressor FLC between wild-type and 35S-GSH1 plants. Unlike other genes responsive to SV treatment, SV-dependent decrease in FLC in wild-type plants was reversed in 35S-GSH1 plants. SV treatment increased GSSG level in wild-type seeds, whereas GSSG level was high in 35S-GSH1 plants, even at a non-vernalizing temperature. Taking into consideration that low temperatures stimulate GSH biosynthesis and bring about oxidative stress, GSSG is considered to trigger low temperature response, but enhanced GSH synthesis was not enough for mimicking SV treatment. To complete it, it essentially required the cellular redox retransition from the oxidized to the reduced state that is observed after the seed vernalization treatment.
Overexpression of GSH1 gene mimics transcriptional response to low temperature during seed vernalization treatment of Arabidopsis.
Specimen part
View SamplesAnalysis to find splicing variants that are differentially expressed in a highly metastatic stomach cancer cell line, MKN45P, versus its parental cell line, MKN45
Identification of a novel protein isoform derived from cancer-related splicing variants using combined analysis of transcriptome and proteome.
Specimen part, Cell line
View SamplesErbB receptor ligands, epidermal growth factor (EGF) and heregulin (HRG), induce dose-dependent transient and sustained intracellular signaling, proliferation and differentiation of MCF-7 breast cancer cells, respectively. In an effort to delineate the ligand-specific cell determination mechanism, we investigated time-course gene expressions induced by EGF and HRG that induce distinct cellular phenotypes in MCF-7 cells. To analyze the effects of ligand dosage and time for the gene expression independently, we developed a statistical method for decomposing the expression profiles into the two effects. Our results indicated that signal transduction pathways devotedly convey quantitative properties of the dose-dependent activation of ErbB receptor to early transcription. The results also implied that moderate changes in the expression levels of numbers of genes, not the predominant regulation of a few specific genes, might cooperatively work at the early stage of the transcription for determining the cell fate. However, the EGF- and HRG-induced distinct signal durations resulted in the ligand-oriented biphasic induction of proteins after 20 min. The selected gene list and HRG-induced prolonged signaling suggested that transcriptional feedback to the intracellular signaling results in a graded to biphasic response in the cell determination process, and that each ErbB receptor is inextricably responsible for the control of amplitude and duration of cellular biochemical reactions.
Quantitative transcriptional control of ErbB receptor signaling undergoes graded to biphasic response for cell differentiation.
Cell line
View SamplesLaser capture microdissection was used to obtain individual LGN layers for DNA microarray of Rhesus array in macaque monkeys that Monocular Visual Deprivation was generated by either opaque dark contact lens or tarsoraphoplasty at birth.
Monocular visual deprivation in macaque monkeys: a profile in the gene expression of lateral geniculate nucleus by laser capture microdissection.
No sample metadata fields
View SamplesAberrant activation of signaling pathways controlled in normal epithelial cells by the epidermal growth factor receptor (EGFR) has been linked to cetuximab (a monoclonal antibody against EGFR) resistance in head and neck squamous cell carcinoma (HNSCC). To infer relevant and specific pathway activation downstream of EGFR from gene expression in HNSCC, we generated gene expression signatures using immortalized keratinocytes (HaCaT) subjected to either ligand stimulation or pharmacological inhibition of the signaling intermediaries PI-3-Kinase and MEK or transfected with EGFR, RELA/p65, or HRASVal12. The gene expression patterns that distinguished the various HaCaT variants and conditions were inferred using the Markov chain Monte Carlo (MCMC) matrix factorization algorithm Coordinated Gene Activity in Pattern Sets (CoGAPS). This approach inferred gene expression signatures with greater relevance to cell signaling pathway activation than the expression signatures inferred with standard linear models. Furthermore, the pathway signature generated using HaCaT-HRASVal12 further associated with the cetuximab treatment response in isogenic cetuximab-sensitive (UMSCC1) and -resistant (1CC8) cell lines. Our data suggest that the CoGAPS algorithm can generate gene expression signatures that are pertinent to downstream effects of receptor signaling pathway activation and potentially be useful in modeling resistance mechanisms to targeted therapies.
Gene expression signatures modulated by epidermal growth factor receptor activation and their relationship to cetuximab resistance in head and neck squamous cell carcinoma.
Cell line, Treatment
View SamplesTransition from proliferation to quiescence brings about extensive changes in cellular behavior and structure. However, genes critical for establishing and/or for maintaining quiescence are largely unknown. The fission yeast S. pombe is found as an excellent model for studying this problem, because it becomes quiescent under nitrogen starvation. Here we characterize 610 temperature-sensitive (ts) mutants, and identify 33 genes required for entry into and the maintenance of quiescence. These genes cover a broad range of cellular functions in the cytoplasm, membrane and the nucleus, encoding proteins for stress-responsive and cell cycle kinase signaling pathway, actin-bound and osmo-controlling endosome formation, RNA transcription, splicing and ribosome biogenesis, chromatin silencing, biosynthesis of lipid and ATP, cell wall and membrane morphogenesis, protein trafficking and vesicle fusion. We specifically highlight Fcp1, CTD phosphatase of RNA polymerase II, which differentially affects transcription of genes involved in quiescence and proliferation. We propose that the transcriptional role of Fcp1 is central to differentiate quiescence from proliferation.
Genetic control of cellular quiescence in S. pombe.
No sample metadata fields
View SamplesIn previous studies, human dental pulp stem cells (hDPSCs) were mainly isolated from adults. In this manuscript, we tried characterization of hDPSCs isolated from an earlier developmental stage to evaluate potential usage of these cells for tissue regenerative therapy. hDPSCs isolated at the crown-completed stage showed a higher proliferation rate than those isolated at the later stage. When the cells from either group were cultured in medium promoting differentiation towards cells of the osteo/odontoblastic lineage, both became alkaline phosphatase positive, produced calcified matrix, and were also capable of forming dentin-like matrix on scaffolds in vivo. However, during long-term passage, these cells underwent a change in morphology and lost their differentiation ability. The results of a DNA array experiment showed that the expression of a number of genes, such as WNT16, was markedly changed with increasing number of passages, which might have caused the loss of their characteristics as hDPSCs.
Characterization of dental pulp stem cells of human tooth germs.
No sample metadata fields
View SamplesAccumulated evidences suggest physiological relevance between the transcription factor NRF3 (NFE2L3) and cancers. However NRF3 target genes in cancer cells remain poorly understood.
Multiple regulatory mechanisms of the biological function of NRF3 (NFE2L3) control cancer cell proliferation.
Specimen part, Cell line
View SamplesTo identify downstream transcription factors induced by retinoic acid, we stimulated SFZ cells with 10 M retinoic acid for 24 hours and performed microarray analysis.
Sox4 is involved in osteoarthritic cartilage deterioration through induction of ADAMTS4 and ADAMTS5.
Specimen part, Treatment
View SamplesDNA methylation has been considered to play an important role during myogenic differentiation. In terminal differentiation of myoblasts, chronological alteration of DNA methylation status was poorly understood. Using Infinium HumanMethylation450 BeadChips, we validated genome wide DNA methylation profiles of human myoblast differentiation models. To investigate correlation between DNA methylation and gene expression, we also assessed gene expression of myoblasts with GeneChip Human Genome U133 Plus 2.0 array.
DNA methylation analysis of human myoblasts during in vitro myogenic differentiation: de novo methylation of promoters of muscle-related genes and its involvement in transcriptional down-regulation.
Sex, Age, Race
View Samples