• Title/Summary/Keyword: reporter assay

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The Inhibitory Effect on Androgen Receptor-Dependent Prostate Cancer Cell Growth by Anti-Histone Acetyltransferase Activity from Terminalia chebula Retz. Fruit Methanol Extract (가자(Terminalia chebula Retz.) 열매 메탄올 추출물의 Histone Acetyltransferase 활성 저해에 따른 항전립선암 효과)

  • Lee, Yoo-Hyun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.10
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    • pp.1539-1543
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    • 2013
  • The inhibitory effect of histone acetyltransferase from methanol extract of Terminalia chebula Retz. fruit (TCME) was investigated in prostate cancer cell. TCME significantly inhibited histone acetyltransferase (HAT) activity by over 50% at 100 ${\mu}g/mL$ concentration. TCME treatment repressed androgen receptor (AR) mediated transcription, mRNA level of AR target genes, prostate specific antigen (PSA) and NKX-3.1, as well as AR acetylation. Finally, the prostate cancer cell viability was dramatically reduced by TCME treatment at 0~100 ${\mu}g/mL$ concentration. These results indicated that TCME, as a potent HAT inhibitor, could suppress prostate cancer cell growth by AR mediated transcription regulation.

Concatemer-Associated Transgene Expression Patterns in Transgenic Marine Medaka Oryzias dancena Strains

  • Cho, Young Sun;Kim, Dong Soo;Nam, Yoon Kwon
    • Fisheries and Aquatic Sciences
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    • v.18 no.1
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    • pp.73-80
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    • 2015
  • To examine the interrelationship between transgenic insertion patterns and transgene expression profiles in established transgenic fish lines, four stable transgenic marine medaka Oryzias dancena germlines harboring ${\beta}$-actin regulator-driven RFP reporter constructs were selected. The established transgenic strains were characterized with regard to their transgenic genotypes (insertion pattern, concatemer formation, and transgene copy number based on genomic Southern blot hybridization and qPCR assay) and expression characteristics at the mRNA (qRT-PCR), protein (western blot), and phenotypic (fluorescent appearance) levels. From comparative examinations, it was found that transgenic expression at both the transcription and translation levels could be significantly downregulated in transgenic strains, potentially through methylation-mediated transgene silencing that was particularly associated with the formation of a long tail-to-head tandem concatemer in the chromosomal integration site(s). When this occurred, an inverse relationship between the transgene copy number and fluorescence intensity was observed in the resultant transgenic fish. However, with the other transgenic genotype, transgenic individuals with an identical Southern blot hybridization pattern, containing a tandem concatemer(s), had very different expression levels (highly robust vs. low expression strengths), which was possibly related to the differential epigenetic modifications and/or degrees of methylation. The concatemer-dependent downregulation of transgene activity could be induced in transgenic fish, but the overall pattern was strain-specific. Our data suggest that neither a low (or single) transgene copy number nor tandem transgene concatemerization is indicative of strong or silenced transgene expression in transgenic fish carrying a ubiquitous transgene. Hence, a sufficient number of transgenic lineages, with different genotypes, should be considered to ensure the establishment of the best-performance transgenic line(s) for practical applications.

Forskolin-Induced Stimulation of RGS2 mRNA in C6 Astrocytoma Cells

  • Kim Sung-Dae;Cho Jae-Youl;Park Hwa-Jin;Kim Sang-Keun;Rhee Man-Hee
    • Biomedical Science Letters
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    • v.12 no.3
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    • pp.131-137
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    • 2006
  • RGS is a negative regulator of G-protein signaling and can be identified by the presence of a conserved $120{sim}125$ amino acid motif, which is referred to as the RGS box. A number of RGSs are induced in response to a wide variety of stimuli. Increased levels of RGSs lead to significant decreases in GPCR responsiveness. To obtain further evidence of a role of RGS proteins in rat C6 astrocytoma cells, we first determined the expression profile of RGS-specific mRNA in C6 cells using reverse transcription-polymerase chain reaction (RT-PCR) with a poly dT18 primer and transcript-specific primers. We found that RGS2, RGS3, RGS6, RGS9, RGS10, RGS12, and RGS16 were differentially expressed in C6 astrocytoma cells. The highest expression rate was found for RGS3, followed by RGS16, RGS10 and RGS9, whereas the expression level for RGS2 was barely detectable. We next assessed whether forskolin regulated the expression of RGSs expressed in C6 astrocytoma cells. The present study found that forskolin dose-dependently stimulated the expression of RGS2 transcripts. This up-regulation of RGS2 gene was abrogated by H-89, potent and broad-spectrum protein kinase A (PKA) inhibitors. Actinomycin D completely inhibited the up-regulation of RGS2 gene induced by forskolin $(10{\mu}M)$, indicating that the regulation of RGS2 gene is controlled at the transcriptional level. In addition, forskolin did significantly activate transcriptional cAMP response element (CRE) in either HEK 293 cells or C6 cells and did not modulate the $NF-{\kappa}B$ and AP-l activity as measured by luciferase reporter gene assay. Finally, forskolin induced the expression of RGS2 mRNA in C6 astrocytoma cells, which depend on the PKA pathway and CRE transcriptional pathways.

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Wnt/$\beta$-catenin/Tcf Signaling Induces the Transcription of a Tumor Suppressor Axin2, a Negative Regulator of the Signaling Pathway

  • Jho, Eek-hoon;Tong Zhang;Claire Domon;Joo, Choun-Ki;Freund, Jean-Noel;Frank Costantini
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2001.11a
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    • pp.108-108
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    • 2001
  • Axin2/Conductin/Axil and its ortholog Axin are negative regulators of the Wnt signaling pathway, which promote the phosphorylation and degradation of ${\beta}$-catenin. While Axin is expressed ubiquitously, Axin2 mRNA was seen in a restricted pattern during mouse embryogenesis and organogenesis. Because many sites of Axin2 expression overlapped with those of several Wnt genes, we tested whether Axin2 was induced by Wnt signaling. Endogenous Axin2 mRNA and protein expression could be rapidly induced by activation of the Wnt pathway, and Axin2 reporter constructs, containing a 5.6 kb DNA fragment including the promoter and first intron, were also induced. This genomic region contains eight Tcf/LEF consensus binding sites, five of which are located within longer, highly conserved non-coding sequences. The mutation or deletion of these Tcf/LEF sites greatly diminished induction by ${\beta}$-catenin, and mutation of the Tcf/LEF site T2 abolished protein binding in an electrophoretic mobility-shift assay. These results strongly suggest that Axin2 is a direct target of the Wnt pathway, mediated through Tcf/LEF factors. The 5.6 kb genomic sequence was sufficient to direct the tissue specific expression of d2EGFP in transgenic embryos, consistent with a role for the Tcf/LEF sites and surrounding conserved sequences in the in vivo expression pattern of Axin2. Our results suggest that Axin2 participates in a negative feedback loop, which could serve to limit the duration or intensity of a Wnt-initiated signal.

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ARYL HYDROCARBON- AND ESTROGEN-MEDIATED SIGNALS POSSIBLY CROSS TALK TO REGULATE CYP1A1 GENE EXPRESSION

  • Joung, Ki-Eun;Kim, Yeo-Woon;Min, Kyung-Nan;Sheen, Yhun-Yhong
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2001.11a
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    • pp.112-112
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    • 2001
  • 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental toxin that activates the aryl hydrocarbon receptor (AhR) and disrupts multiple endocrine signaling pathways by enhancing ligand metabolism, altering hormone synthesis, down regulating receptor levels, and interfering with gene transcription. And TCDD-mediated gene transactivation via the AhR has been shown to be dependent upon estrogen receptor (ER) expression in human breast cancer cells. In the present study, we have examined the effect of natural estrogen, phytoestrognes and environmental estrogens on the regulation of CYP1A1 gene expression in MCF-7 human breast cancer cell line. that ER and AhR are co-expressed. pCYP1A1 -luc reporter gene was transiently transfected into MCF-7 cells. These cells were treated with various chemicals and then luciferase assay was carried out. 17be1a-estradiol significantly inhibited TCDD stimulated luciferase activity dose dependently and this inhibition was partially recovered by concomitant treatment of tamoxifen. 17beta-estradiol metabolites, 2-hydroxyestradiol and 16alpha-estriol resulted in less potent inhibitory effect than estradiol and synthetic estrogen, diethylstilbestrol (DES) showed no effect on CYP1A1 gene expression. This study demonstrated that estrogen down-regulated TCDD stimulated CYP1A1 expression via ER mediation. And we have found out that several flavonoids such as genistein, kaempferol, daidzein, naringenin, and alkylphenols such as nonylphenol, 4-octylphenol and resveratrol also inhibited TCDD induced CYP1A1 expression like estrogen.

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Development of Plant Regeneration and Genetic Transformation System from Shoot Apices of Sorghum bicolor (L.) Moench

  • Syamala, D.;Devi, Prathibha
    • Journal of Plant Biotechnology
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    • v.6 no.2
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    • pp.77-85
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    • 2004
  • Development of efficient plant regeneration and genetic transformation protocols (using the Particle Inflow micro-projectile Gun and the shoot-tips as target tissue) of Sorghum bicolor (L.) Moench in terms of expression of the reporter gene, $\beta$-glucuronidase(uidA) is reported here. Two Indian cultivars of sorghum were used in the study, viz. M-35-1 and CSV-15. Plant regeneration was achieved from one-week-old seedling shoot-tip explants via multiple-shoot-clumps and also somatic embryos. The multiple-shoot-clumps were produced on MS medium containing BA (0.5, 1.0 or 2.0 mg/$L^{-1}$), with biweekly subculture. Somatic embryos were directly produced on the enlarged dome shaped expansive structures that developed from shoot-tip explants (without any callus formation) when cultured on MS medium supplemented both with BA (0.5, 1.0 or 2.0 mg/$L^{-1}$) and 2,4-D (0.5 mg/$L^{-1}$). Whereas each multiple-shoot-clump was capable of regenerating more than 80 shoots via an intensive differentiation of both axillary and adventitious shoot buds, the somatic embryos were capable of 90% germination, plant conversion and regeneration. The regenerated shoots could be efficiently rooted on MS medium containing 1.0mg/$L^{-1}$ IBA and successfully transplanted to the glasshouse and grown to maturity with a survival rate of 92%. The plant regeneration efficiency of both the genotypes were similar. After the micro-projectile bombardment, expression of uidA gene was determined by scoring blue transformed cell sectors in the bombarded tissue by an in situ enzyme assay. The optimal conditions comprising a helium pressure of 2200 K Pa, the target distance of 11 cm with helium inlet fully opened and the use of osmoticum have been defined to aid our future strategies of genetic engineering in sorghum with genes for tolerance to biotic and abiotic stresses.

Post-Transcriptional Control of Tropoelastin in Aortic Smooth Muscle Cells Affects Aortic Dissection Onset

  • Qi, You-Fei;Shu, Chang;Xiao, Zhan-Xiang;Luo, Ming-Yao;Fang, Kun;Guo, Yuan-Yuan;Zhang, Wen-Bo;Yue, Jie
    • Molecules and Cells
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    • v.41 no.3
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    • pp.198-206
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    • 2018
  • Aortic dissection (AD) is a catastrophic disease with high mortality and morbidity, characterized with fragmentation of elastin and loss of smooth muscle cells. Although AD has been largely attributable to polymorphisms defect in the elastin-coding gene, tropoelastin (TE), other undermined factors also appear to play roles in AD onset. Here, we investigated the effects of post-transcriptional control of TE by microRNAs (miRNAs) on elastin levels in aortic smooth muscle cells (ASMC). We found that miR-144-3p is a miRNA that targets TE mRNA in both human and mouse. Bioinformatics analyses and dual luciferase reporter assay showed that miR-144-3p inhibited protein translation of TE, through binding to the 3'-UTR of the TE mRNA. Interestingly, higher miR-144-3p levels and lower TE were detected in the ASMC obtained from AD patients, compared to those from non-AD controls. In a mouse model for human AD, infusion of adeno-associated viruses (serotype 6) carrying antisense for miR-144-3p (asmiR-144-3p) under CAG promoter significantly reduced the incidence and severity of AD, seemingly through enhancement of TE levels in ASMC. Thus, our data suggest an essential role of miR-144-3p on the pathogenesis of AD.

Mechanism of Action of Nigella sativa on Human Colon Cancer Cells: the Suppression of AP-1 and NF-κB Transcription Factors and the Induction of Cytoprotective Genes

  • Elkady, Ayman I;Hussein, Rania A;El-Assouli, Sufian M
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.17
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    • pp.7943-7957
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    • 2015
  • Background and Aims: Colorectal cancer is one of the leading causes of death in the world. The aim of this study was to investigate the growth-suppression potentiality of a crude saponin extract (CSENS) prepared from medicinal herb, Nigella sativa, on human colon cancer cells, HCT116. Materials and Methods: HCT116 cells were subjected to increasing doses of CSENS for 24, 48 and 72 h, and then harvested and assayed for cell viability by WST-1. Flow cytometry analyses, cell death detection ELISA, fluorescent stains (Hoechst 33342 and acridine orange/ethidium bromide), DNA laddering and comet assays were carried out to confirm the apoptogenic effects of CSENS. Luciferase reporter gene assays, quantitative reverse transcription-polymerase chain reaction and Western blot analyses were performed to assess the impact of CAERS and CFEZO on the expression levels of key regulatory proteins in HCT116 cells. Results: The results demonstrated that CSENS inhibited proliferation and induced apoptosis. Apoptosis was confirmed by flow cytometry analyses, while CSENS-treated cells exhibited morphological hallmarks of apoptosis including cell shrinkage, irregularity in cellular shape, cellular detachment and chromatin condensation. Biochemical signs of apoptosis, such as DNA degradation, were observed by comet assay and gel electrophoresis. The pro-apoptotic effect of CSENS was caspase-3-independent and associated with increase of the Bax/Bcl-2 ratio. CSENS treatment down-regulated transcriptional and DNA-binding activities of NF-${\kappa}B$ and AP-1 proteins, associated with down-regulation of their target oncogenes, c-Myc, cyclin D1 and survivin. On the other hand, CSENS up-regulated transcriptional and DNA-binding activities of Nrf2 and expression of cytoprotective genes. In addition, CSENS modulated the expression levels of ERK1/2 MAPK, p53 and p21. Conclusions: These findings suggest that CSENS may be a valuable agent for treatment of colon cancer.

TI-I-174, a Synthetic Chalcone Derivative, Suppresses Nitric Oxide Production in Murine Macrophages via Heme Oxygenase-1 Induction and Inhibition of AP-1

  • Kim, Mi Jin;Kadayat, Taraman;Kim, Da Eun;Lee, Eung-Seok;Park, Pil-Hoon
    • Biomolecules & Therapeutics
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    • v.22 no.5
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    • pp.390-399
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    • 2014
  • Chalcones (1,3-diaryl-2-propen-1-ones), a flavonoid subfamily, are widely known for their anti-inflammatory properties. Propenone moiety in chalcones is known to play an important role in generating biological responses by chalcones. In the present study, we synthesized chalcone derivatives structurally modified in propenone moiety and examined inhibitory effect on nitric oxide (NO) production and its potential mechanisms. Among the chalcone derivatives used for this study, TI-I-174 (3-(2-Hydroxyphenyl)-1-(thiophen-3-yl)prop-2-en-1-one) most potently inhibited lipopolysaccharide (LPS)-stimulated nitrite production in RAW 264.7 macrophages. TI-I-174 treatment also markedly inhibited inducible nitric oxide synthase (iNOS) expression. However, TI-I-174 did not significantly affect production of IL-6, cyclooxygenase-2 (COX-2) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), implying that TI-I-174 inhibits production of inflammatory mediators in a selective manner. Treatment of macrophages with TI-I-174 significantly inhibited transcriptional activity of activator protein-1 (AP-1) as determined by luciferase reporter gene assay, whereas nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activity was not affected by TI-I-1744. In addition, TI-I-174 significantly inhibited activation of c-Jun-N-Terminal kinase (JNK) without affecting ERK1/2 and p38MAPK, indicating that down-regulation of iNOS gene expression by TI-I-174 is mainly attributed by blockade of JNK/AP-1 activation. We also demonstrated that TI-I-174 treatment led to an increase in heme oxygenase-1 (HO-1) expression both at mRNA and protein level. Transfection of siRNA targeting HO-1 reversed TI-I-174-mediated inhibition of nitrite production. Taken together, these results indicate that TI-I-174 suppresses NO production in LPS-stimulated RAW 264.7 macrophages via induction of HO-1 and blockade of AP-1 activation.

The Evaluation of the Effect of Herbal Extract on Osteoarthritis: In Vitro and In Vivo Study

  • Kim, Jaeyong;Yang, Siyoung;Choi, Chul-yung
    • Preventive Nutrition and Food Science
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    • v.21 no.4
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    • pp.310-316
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    • 2016
  • In this study, the anti-osteoarthritis effects of Cynanchum wilfordii, Phlomis umbrosa, and Angelica gigas extract (CPAE), observed and confirmed in previously clinical studies were further investigated by in vitro and in vivo studies. Anabolic biomarkers related to healthy cartilage maintenance, such as aggrecan, type II collagen ${\alpha}$-1 (Col2a1), sex determining region Y-box-9 (Sox-9), and catabolic biomarkers related to osteoarthritis, such as cyclooxygenase-2 (Cox-2), matrix metalloproteinase-13 (Mmp13), and nuclear factor kappa-light-chain-enhancer of activated B cells ($Nf{\kappa}b$), were evaluated by quantitative reverse transcriptase polymerase chain reaction and reporter gene assay. In vitro study results showed significant changes in both anabolic and catabolic biomarkers. For anabolic factors, significant changes in the level of aggrecan (P<0.05), Col2a1 (P<0.05), and Sox-9 (P<0.01) activation were shown after treatment of cartilage cells with CPAE (50 ng/mL) with similar efficacy compared to insulin growth factor, the positive control (100 ng/mL). For catabolic factors, significant changes in the inhibition activity of Cox-2 (P<0.05), Mmp13 (P<0.01), and $Nf{\kappa}b$ (P<0.05) were shown for CPAE (50 ng/mL) with similar efficacy compared to Celecoxib, the positive control ($10{\mu}M$). In the in vivo carrageenan-induced paw edema model study results showed that CPAE-treated groups (100 mg/kg) and Celecoxib-treated groups (60 mg/kg) showed comparably significant efficacy of inhibition by 37.1% and 52.1%, respectively. Furthermore, CPAE (200 mg/kg) showed similar effect to Celecoxib (60 mg/kg) with an inhibition rate of 54.3%. This result confirms that CPAE effectively inhibited the inflammation-induced osteoarthritis symptoms.