Quercetin is a flavonol modifying numerous cell processes with potent antiproliferative effects on cancer cell-lines. The aim of this study was to explore by gene-array analysis the effect of quercetin on cancer-related gene expression in HepG2 cells, followed by verification with RT-PCR and analysis of the expected phenotypic changes (migration, cell cycle, cell proliferation). Quercetin induces significant changes on cell-adhesion related genes, leading to reduced migratory capacity and disorganization of the actin cytoskeleton. Several genes related to DNA functions, cellular metabolism and signal-transducer activities were also modified, while an early effect on Gprotein related cascades possibly via protease-activated receptor 2 and phospholipase C-1 was identified. Cyclin-D associated events in G1 and ubiquitin-dependent degradation of cyclin-D1 were also affected, resulting in cell-cycle arrest without activation of apoptosis pathways. In conclusion quercetin (3M) exerts its cellular effects by modifying numerous genes related to mechanisms involved in cancer initiation and promotion.
Quercetin accumulates in nuclear structures and triggers specific gene expression in epithelial cells.
Cell line
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Specificity and heterogeneity of terahertz radiation effect on gene expression in mouse mesenchymal stem cells.
Specimen part
View SamplesWe report that terahertz (THz) irradiation of mouse mesenchymal stem cells with a pulsed broadband (centered at 10 THz) source, or a single-frequency, 2.52 THz, (SF) laser source, both with weak average power (<1mW/cm2), results in specific heterogenic changes in gene expression. The insignificant differential expression of heat shock and stress related genes as well as our temperature measurements imply a non-thermal response. The microarray survey and RT-PCR experiments demonstrate that at different irradiation conditions distinct groups of genes are activated. Stem cells irradiated for 12 hours with the broadband THz source exhibit an accelerated differentiation toward adipose phenotype, while the 2-hour (broadband or SF) irradiation affects genes transcriptionally active in pluripotent stem cells. Phenotypic and gene expression differences suggest that the THz effect depends on irradiation parameters such as duration and type of THz source, and on the level of stem cell differentiation. Computer simulations of the core promoters of two pluripotency markers reveal association between gene upregulation and propensity for DNA breathing. We propose that THz radiation has potential for non-contact control of cellular gene expression.
Specificity and heterogeneity of terahertz radiation effect on gene expression in mouse mesenchymal stem cells.
Specimen part
View SamplesWe report that terahertz (THz) irradiation of mouse mesenchymal stem cells with a pulsed broadband (centered at 10 THz) source, or a single-frequency, 2.52 THz, (SF) laser source, both with weak average power (<1mW/cm2), results in specific heterogenic changes in gene expression. The insignificant differential expression of heat shock and stress related genes as well as our temperature measurements imply a non-thermal response. The microarray survey and RT-PCR experiments demonstrate that at different irradiation conditions distinct groups of genes are activated. Stem cells irradiated for 12 hours with the broadband THz source exhibit an accelerated differentiation toward adipose phenotype, while the 2-hour (broadband or SF) irradiation affects genes transcriptionally active in pluripotent stem cells. Phenotypic and gene expression differences suggest that the THz effect depends on irradiation parameters such as duration and type of THz source, and on the level of stem cell differentiation. Computer simulations of the core promoters of two pluripotency markers reveal association between gene upregulation and propensity for DNA breathing. We propose that THz radiation has potential for non-contact control of cellular gene expression.
Specificity and heterogeneity of terahertz radiation effect on gene expression in mouse mesenchymal stem cells.
Specimen part
View SamplesWe report that terahertz (THz) irradiation of mouse mesenchymal stem cells with a pulsed broadband (centered at 10 THz) source, or a single-frequency, 2.52 THz, (SF) laser source, both with weak average power (<1mW/cm2), results in specific heterogenic changes in gene expression. The insignificant differential expression of heat shock and stress related genes as well as our temperature measurements imply a non-thermal response. The microarray survey and RT-PCR experiments demonstrate that at different irradiation conditions distinct groups of genes are activated. Stem cells irradiated for 12 hours with the broadband THz source exhibit an accelerated differentiation toward adipose phenotype, while the 2-hour (broadband or SF) irradiation affects genes transcriptionally active in pluripotent stem cells. Phenotypic and gene expression differences suggest that the THz effect depends on irradiation parameters such as duration and type of THz source, and on the level of stem cell differentiation. Computer simulations of the core promoters of two pluripotency markers reveal association between gene upregulation and propensity for DNA breathing. We propose that THz radiation has potential for non-contact control of cellular gene expression.
Specificity and heterogeneity of terahertz radiation effect on gene expression in mouse mesenchymal stem cells.
Specimen part
View SamplesWe report that extended exposure to broad-spectrum terahertz radiation results in specific changes in cellular functions that are closely related to DNA-directed gene transcription. Our gene chip survey of gene expression shows that whereas 89% of the protein coding genes in mouse stem cells do not respond to the applied teraherz radiation, certain genes are activated, while other are repressed. RT-PCR experiments with selected gene probes corresponding to transcripts in the three groups of genes detail the gene specific effect. The response was not only gene specific but also irradiation conditions dependent. Our findings suggest that the applied terahertz irradiation accelerates cell differentiation toward adipose phenotype by activating the transcription factor peroxisome proliferator-activated receptor gamma (PPARG). Finally, our molecular dynamics computer simulations indicate that the local breathing dynamics of the PPARG promoter DNA coincides with the gene specific response to the THz radiation. We propose that THz radiation is a potential tool for cellular reprogramming.
Mammalian stem cells reprogramming in response to terahertz radiation.
Specimen part, Treatment
View SamplesAPRIL (TNFSF13) is a ligand of the TNF superfamily which binds to two receptors, BCMA and TACI. We have found that APRIL and its receptor BCMA are specifically enhanced in hepatocellular carcinoma, as compared to non-cancerous liver tissue. We further identified that HepG2 cells present the same ligand/receptor pattern as human hepatocellular carcinomas. We investigated the role of APRIL in HepG2 gene expression in a time course study.
APRIL binding to BCMA activates a JNK2-FOXO3-GADD45 pathway and induces a G2/M cell growth arrest in liver cells.
Specimen part, Cell line
View SamplesThis experiment tests the hypothesis that interleukin-1 promotes SMC phenotypic modulation to a distinct inflammatory state relative to the growth factor PDGF-DD.
Interleukin-1β modulates smooth muscle cell phenotype to a distinct inflammatory state relative to PDGF-DD via NF-κB-dependent mechanisms.
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View SamplesMurine Cytomegalovirus (MCMV) infection leads to early activation of various immune cells, including B and T lymphocytes, before the actual initiation of antigen-specific adaptive immunity. This activation is partly driven by innate cytokines, including type I interferon (IFN), which are induced early after infection. The objective of this study was to address the role of type I IFN in shaping early/innate B and T cell responses to a primary acute viral infection.
Plasmacytoid, conventional, and monocyte-derived dendritic cells undergo a profound and convergent genetic reprogramming during their maturation.
Specimen part
View SamplesHsp70 inhibition affects many signaling pathways. We established how these effects are translated into changes in gene expression.
Cancer cell responses to Hsp70 inhibitor JG-98: Comparison with Hsp90 inhibitors and finding synergistic drug combinations.
Cell line
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