• Title/Summary/Keyword: ctDNA

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Changes in Polyamine Level and Chloroplast DNA Methylation in Chlamydomonas reinhardtii (Chlamydomonas의 Polyamine 함량변화와 엽록체 DNA Methylation)

  • 이순희
    • Journal of Plant Biology
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    • v.37 no.1
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    • pp.101-109
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    • 1994
  • Relationship between polyamine level and DNA methylation in the absence or presence of MGBG(l mM), which is an enzyme-activated reversible inhibitor of SAMDC, has been investigated during gametogenesis of Chlamydomonas. In the absence of MGBG, polyamine levels decreased in Chlamydomonas 137C(+) and 137C(-) during gametogenesis. And polyamine level of 137C(+) was 2-5 times as much as that of 137C(-) and showed a significant decrease unlike that of 137C(-). In vitro, MGBG inhibited ctDNA methylation of 137C(+) by 20-30% but did not inhibited that of 137C(-). Also, MGBG inhibited DNA methylase by 60% in vitro. The results obtained in the present work suggest the possibility that the changes of polyamine level may be associated with ctDNA methylation during gametogenesis of Chlamydomonas.omonas.

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Development and Validation of Real-time PCR to Determine Branchiostegus japonicus and B. albus Species Based on Mitochondrial DNA (Real-time PCR 분석법을 이용한 옥돔과 옥두어의 종 판별법 개발)

  • Chung, In Young;Seo, Yong Bae;Yang, Ji-Young;Kim, Gun-Do
    • Journal of Life Science
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    • v.27 no.11
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    • pp.1331-1339
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    • 2017
  • DNA barcoding is the identification of a species based on the DNA sequence of a fragment of the cytochrome C oxidase subunit I (COI) gene in the mitochondrial genome. It is widely applied to assist with the sustainable development of fishery-product resources and the protection of fish biodiversity. This study attempted to verify horse-head fish (Branchiostegus japonicus) and fake horse-head fish (Branchiostegus albus) species, which are commonly consumed in Korea. For the validation of the two species, a real-time PCR method was developed based on the species' mitochondrial DNA genome. Inter-species variations in mitochondrial DNA were observed in a bioinformatics analysis of the mitochondrial genomic DNA sequences of the two species. Some highly conserved regions and a few other regions were identified in the mitochondrial COI of the species. In order to test whether variations in the sequences were definitive, primers that targeted the varied regions of COI were designed and applied to amplify the DNA using the real-time PCR system. Threshold-cycle (Ct) range results confirmed that the Ct ranges of the real-time PCR were identical to the expected species of origin. Efficiency, specificity and cross-reactivity assays showed statistically significant differences between the average Ct of B. japonicus DNA ($21.85{\pm}3.599$) and the average Ct of B. albus DNA ($33.49{\pm}1.183$) for confirming B. japonicus. The assays also showed statistically significant differences between the average Ct of B. albus DNA ($22.49{\pm}0.908$) and the average Ct of B. japonicus DNA ($33.93{\pm}0.479$) for confirming B. albus. The methodology was validated by using ten commercial samples. The genomic DNA-based molecular technique that used the real-time PCR was a reliable method for the taxonomic classification of animal tissues.

MODULATION OF INSULIN-STIMULATED DNA SYNTHESIS BY CHOLERA TOXIN IN BOVINE MAMMARY FIBROBLASTS

  • Yuh, I.S.;Park, C.K.;Han, J.Y.;Sheffield, L.G.
    • Asian-Australasian Journal of Animal Sciences
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    • v.6 no.4
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    • pp.483-489
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    • 1993
  • Bovine fibroblasts were cultured in Dulbecco's Modified Eagle's Medium and then treated with control, insulin (I, $1{\mu}g/ml$), cholera toxin (CT, 0.1-100 ng/ml) or CT (0.1-100 ng/ml) + I ($1{\mu}g/ml$). Cholera toxin, an activator of adenylate cyclase, significantly decreased insulin induced DNA synthesis (p<0.05). The modulation of DNA synthesis apparently involves events occurring in early stage of cell growth, at least between the first 4 and 8 hour of CT treatment. Insulin induced collagen as well as noncollagen synthesis in cell layer, however, these syntheses were reduced by addition of cholera toxin (p<0.05) but were not completely reduced. It is not clear whether the reduction of insulin-induced cell layer collagen or noncollagen proteins by CT is involved in the inhibitory effect on insulin-induced DNA synthesis. However, we could rule out the hypothesis that insulin-induced DNA synthesis is reduced by CT-induced cellular differentiation.

Role of Liquid Biopsies in Colorectal Cancer (대장암에서 액체 생검의 역할)

  • Kim, Sang Hyun;Keum, Bora
    • Journal of Digestive Cancer Reports
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    • v.8 no.1
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    • pp.56-60
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    • 2020
  • In recent years, liquid biopsy has received immense attention. Liquid biopsy is a minimally invasive method used for obtaining biological fluids including urine, pleural fluid and, mostly, peripheral blood. Liquid biopsy involves various targets including circulating tumors cells (CTCs), circulating cell-free tumor DNA (ctDNA), and microRNA (miRNA). Colorectal cancer (CRC), like other solid tumors, shed tumor cells into the bloodstream. Analysis of these CTCs, as well as ctDNA is the primary objective of the liquid biopsy. Evaluation of CTC or ctDNA offers information about early tumor release, development of tumor metastasis and also about mechanisms involved in tumor resistance to treatment.

The Effects of Anti-Alzheimer on CT105-induced PC 12 Cells by Corynoxeine Isolated from Uncariae Ramulus et Uncus (pCT105로 원격 유도된 PC12 세포에서 조구등으로부터 분리한 corynoxeine의 항치매 효과)

  • Kang Hyung Won;Kim Sang Tae;Lyu Yeoung Su
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.4
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    • pp.1111-1119
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    • 2004
  • In this study, we investigated that the effects of corynoxeine on the apoptosis by inducible CT105 in PC 12 cells and neuronpathogenic agent as CT105 confirmed with apoptosis, DNA fragmentation, neurite outgrowth and immunocytochemistry analysis This study examines whether corynoxeine have an anti-alzhmeimer agent by inhibition of apoptosis by CT105 and induces neurite outgrowth. Cytotoxicity was assessed in PC12 cell cultures by DNA fragmentation and measuring lactate dehydrogenase (LDH) in the culture media. The treatment of corynoxeine in exposure of cultures to CT105 and provided complete protection against cytotoxicity. CT105-induced cytotoxicity was blocked by apoptotsis, repaired by DNA fragmentation, neurite outgrowth and exposure to CT105 expression and regenerated with neurite outgrowth and immunocytochemistry by corynoxeine. These results indicate that in neuronal cell cultures, damage of T105, repaired excitotoxicity by corynoxeine and CT105-induced cytotoxicity is blocked primarily by the activation of anti-apoptosis.

Interaction of ct-DNA with 2,4-Dihydroxy Salophen

  • Azani, Mohammad-Reza;Hassanpour, Azin;Bordbar, Abdol-Khalegh;Mirkhani, Valiollah
    • Bulletin of the Korean Chemical Society
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    • v.30 no.9
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    • pp.1973-1977
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    • 2009
  • In the present study, at first, 2,4-Dihydroxy Salophen (2,4-DHS), has been synthesized by combination of 1, 2-diaminobenzene and 2,4-dihydroxybenzaldehyde in a solvent system. This ligand containing meta-quinone functional groups were characterized using UV-Vis and IR spectroscopies. Subsequently, the interaction between native calf thymus deoxyribonucleic acid (ct-DNA) and 2,4-DHS, was investigated in 10 mM Tris/HCl buffer solution, pH 7.2, using UV-visible absorption and fluorescence spectroscopies, thermal denaturation technique and viscosity measurements. From spectrophotometric titration experiments, the binding constant of 2,4-DHS with ct-DNA was found to be (1.1 ${\pm}\;0.2)\;{\times}\;10^4\;M^{-1}.$ The fluorescence study represents the quenching effect of 2,4-DHS on bound ethidium bromide to DNA. The quenching process obeys linear Stern-Volmer equation in extended range of 2,4-DHS concentration. Thermal denaturation experiments represent the increasing of melting temperature of DNA (about 3.5 ${^{\circ}C}$) due to binding of 2,4-DHS. These results are consistent with a binding mode dominated by interactions with the groove of ct-DNA.

Circulating Cell-free Tumor Nucleic Acids in Gastric Cancer (위암에서의 순환종양핵산)

  • Lee, Hyun-Ji;Lee, Sun Min
    • The Korean journal of helicobacter and upper gastrointestinal research
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    • v.18 no.3
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    • pp.168-173
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    • 2018
  • Gastric cancer is still the leading cause of cancer deaths, especially in Asian countries. Recently, many studies have analyzed cell-free nucleic acids (cfNAs) circulating in the blood, for the early diagnosis of cancer and monitoring its progression. Circulating tumor nucleic acids (ctNAs) originate in a tumor and contain tumor-related genetic or epigenetic alterations. This review defines the nomenclatures of each form of cfNAs and describes the characteristics of circulating tumor DNA (ctDNA) and microRNA (miRNA), two major forms of ctNAs studied in gastric cancer research to date. We compare available studies on ctDNA, and explain trends observed in studies of miRNAs in gastric cancers. As these new blood-based biomarkers have attracted increasing attention, we have discussed several important points to be considered before the clinical translation of ctNA detection. We have also discussed the current status of research in this field, and clinical applications of specific ctNAs as tumor markers for gastric cancer diagnosis.

Study of Interaction of Native DNA with Iron(III)-(2,4-Dihydroxysalophen)chloride (천연 DNA와 2,4-디히드록시살로펜-염화철(III)과 의 상호작용 연구)

  • Azani, Mohammad-Reza;Hassanpour, Azin;Bordbar, Abdol-Khalegh
    • Journal of the Korean Chemical Society
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    • v.54 no.5
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    • pp.573-578
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    • 2010
  • In this study, iron(III)-2,4-dihydroxysalophen chloride (Fe(2,4-DHSalophen)Cl), has been synthesized by combination of 2,4-dihydroxysalophen (2,4-DHSalophen) with $FeCl_2$ in a solvent system. This complex combination was characterized using UV-vis and IR spectroscopies. Subsequently, the interaction between native calf thymus deoxyribonucleic acid (ct-DNA) and Fe(2,4-DHSalophen)Cl, was investigated in 10 mM Tris/HCl buffer solution, pH 7.2, using UV-visible absorption and fluorescence spectroscopies, thermal denaturation technique and viscosity measurements. From spectrophotometric titration experiments, the binding constant of Fe(2,4-DHSalophen)Cl with ct-DNA was found to be $(1.6{\pm}0.2){\times}10^3\;M^{-1}$. The fluorescence study represents the quenching effect of Fe(2,4-DHSalophen)Cl on bound ethidium bromide to DNA. The quenching process obeys linear Stern-Volmer equation in extended range of Fe(2,4-DHSalophen)Cl concentration. Thermal denaturation experiments represent the increasing melting temperature of DNA (about $4.3^{\circ}C$) due to binding of Fe(2,4-DHSalophen)Cl. These results are consistent with a binding mode dominated by interactions with the groove of ct-DNA.

DNA-Binding and Thermodynamic Parameters, Structure and Cytotoxicity of Newly Designed Platinum(II) and Palladium(II) Anti-Tumor Complexes

  • Mansouri-Torshizi, Hassan;Saeidifar, Maryam;Khosravi, Fatemeh;Divsalar, Adeleh;Saboury, Ali.Akbar;Ghasemi, Zahra Yekke
    • Bulletin of the Korean Chemical Society
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    • v.32 no.3
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    • pp.947-955
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    • 2011
  • The complexes [Pd(bpy)(Hex-dtc)]$NO_3$ and [Pt(bpy)(Hex-dtc)]$NO_3$ (bpy is 2,2'-bipyridine and Hex-dtc is hexyldithiocarbamato ligands) were synthesized and characterized by elemental analysis and spectroscopic studies. The cytotoxicity assay of the complexes has been performed on chronic myelogenous leukemia cell line, K562, at micromolar concentration. Both complexes showed cytotoxic activity far better than that of cisplatin under the same experimental conditions. The binding parameters of the complexes with calf thymus DNA (CT-DNA) was investigated using UV-visible and fluorescence techniques. They show the ability of cooperatively intercalating in CT-DNA. Gel filtration studies demonstrated that platinum complex could cleave the DNA. In the interaction studies between the Pd(II) and Pt(II) complexes with CT-DNA, several binding and thermodynamic parameters have been determined, which may provide deeper insights into the mechanism of action of these types of complexes with nucleic acids.

Characterization and Tissues Distribution of Vinculin, Agouti-relating Protein and Melanocortin 4 Receptor Genes in Rainbow Trout, Oncorhynchus mykiss

  • Yoon, Jong-Man
    • Development and Reproduction
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    • v.14 no.4
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    • pp.261-268
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    • 2010
  • As in the O. mykiss electrophoretic profiles of RNA, the signals of each RNA sample from 9 individual tissues such as liver, muscle, brain, heart, pituitary gland, kidney, intestine, spleen and gill similar to positive control were obtained. The tissue distributions of the complimentary DNA (cDNA) of O. mykiss four genes were analyzed using quantitative real-time PCR with primer sets for tissue expression analysis. In this rainbow trout species, author obtained bands of various sizes, ranged from 700 bp to 1,400 bp. A dissociation curve was made at the end of each run to make sure that there was no non-specific amplification. Supplementarily, the Ct of each DNA was compared. The Ct values of vinculin with rainbow trout tissues were determined in a manner similar to those for agouti-related protein (AgRP) and melanocortin receptors (MC4R I and MC4R II). Further, obtained Cts for standard curve of each DNA were affected by specific product (vinculin, AgRP and MC4R II genes). After several experiments with four individual genes of rainbow trout, author estimated a variation ratio of the mean Ct value of the DNA extracted using the comparative CTt method was 37.27, and the standard deviation was 5.33. The correlation coefficient between the Ct values and the concentration of cDNA was -0.98, -0.99, -0.91 and -0.86, respectively (vinculin, AgRP, MC4R I and MC4R II genes). Since this correlation showed high linearity, the straight line obtained was used as a standard for the O. mykiss tissues reared in aquarium. A PCR efficiency of 100% is ideally achieved when the slopes are close to the theoretical value of -3.31. According to quantification method, the results of quantification are strongly affected by the DNA fragmentation. The size of most DNA fragments obtained from various tissues of rainbow trout used in the experiment was approximately 100 bp. According to the four slopes, an efficiency of nearly 100% was estimated for four genes detection methods. Additionally, further analysis with more individuals and primers will be required to fully establish optimization in rainbow trout.