Expression phenotype changes of EBV-transformed lymphoblastoid cell lines during long-term subculture and its clinical significance

Lee, J.-E.,Nam, H.-Y.,Shim, S.-M.,Bae, G.-R.,Han, B.-G.,Jeon, J.-P. Blackwell Publishing Ltd 2010 Cell proliferation Vol.43 No.4

<P>Abstract</P><P>Objectives: </P><P>The EBV-transformed lymphoblastoid cell line (LCL) is a useful resource for population-based human genetic and pharmacogenetic studies. The principal objective here was to assess expression phenotype changes during long-term subculture of LCLs, and its clinical significance.</P><P>Materials and methods: </P><P>We searched for genes that were differentially expressed in 17 LCLs at late (p161) passage compared to early passage (p4) using microarray assay, then validated them by real-time RT-PCR analysis. In addition, we estimated correlations between expression phenotypes of 20 LCL strains at early passage and 23 quantitative clinical traits from blood donors of particular LCL strains.</P><P>Results: </P><P>Transcript sequences of 16 genes including nuclear factor-&kgr;B (NF-&kgr;B) pathway-related genes (such as <I>PTPN13</I>, <I>HERC5</I> and miR-146a) and carcinogenesis-related genes (such as <I>XAF1</I>, <I>TCL1A</I>, <I>PTPN13</I>, <I>CD38</I> and miR-146a) were differentially expressed (>2-fold change) in at least 15 of the 17 LCL strains. In particular, <I>TC2N</I>, <I>FCRL5</I>, <I>CD180</I>, <I>CD38</I> and miR-146a were downregulated in all 17 of the evaluated LCL strains. In addition, we identified clinical trait-associated expression phenotypes in LCLs.</P><P>Conclusion: </P><P>Our results showed that LCLs acquired expression phenotype changes involving expression of NF-&kgr;B pathway- and carcinogenesis-related genes during long-term subculture. These differentially expressed genes can be considered to be a gene signature of LCL immortalization or EBV-induced carcinogenesis. Clinical trait-associated expression phenotypes should prove useful in the discovery of new candidate genes for particular traits.</P>

Report of the CCQM-K97: measurement of arsenobetaine standard solution and arsenobetaine content in fish tissue (tunafish)

Ma, L D,Wang, J,WEI, C,Kuroiwa, T,Narukawa, T,Ito, N,HIOKI, A,CHIBA, K,Yim, Y H,Lee, K S,Lim, Y R,Turk, G C,Davis, C W,Mester, Z,Yang, L,McCooeye, M,Maxwell, P,Cankur, O,Tokman, N,Coskun, F G BUREAU INTERNATIONAL DES POIDS ET MESURES 2017 METROLOGIA -BERLIN- Vol.54 No.-

<P></P> <P>The CCQM-K97 key comparison was organized by the inorganic analysis working group (IAWG) of CCQM as a follow-up to completed pilot study CCQM-P96 and P96.1 to test the abilities of the national metrology institutes to accurately quantitate the mass fraction of arsenobetaine (AsB) in standard solution and in fish tissue. A pilot study CCQM-P133 was parallelized with this key comparison. National Institute of Metrology (NIM), China and National Metrology Institute of Japan (NMIJ) acted as the coordinating laboratories.</P> <P>Six NMIs participated in CCQM-K97 and two institutes participated in CCQM-P133, and all of them submitted the results. Some NMIs submitted more than one results by different methods. The results were in excellent agreement with each other, and obviously better than those of previous P96 and P96.1. Therefore the calibrant which each NMI used was comparable. It shows that the capabilities of some of the participants have been improved after the previous pilot studies.</P> <H2>Main text</H2> <P> To reach the main text of this paper, click on <A HREF='http://www.bipm.org/utils/common/pdf/final_reports/QM/K97/CCQM-K97.pdf'>Final Report</A>. Note that this text is that which appears in Appendix B of the BIPM key comparison database <A HREF='http://kcdb.bipm.org/'>kcdb.bipm.org/</A>.</P> <P>The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).</P>

High performance photodiodes based on chemically processed Cu doped SnS₂ nanoflakes

Mohan Kumar, G.,Xiao, Fu,Ilanchezhiyan, P.,Yuldashev, Sh.,Madhan Kumar, A.,Cho, H.D.,Lee, D.J.,Kang, T.W. Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.455 No.-

<P><B>Abstract</B></P> <P>In this work, Cu doped SnS<SUB>2</SUB> nanoflakes were synthesized through a simple hydrothermal method. The influence of Cu doping on the structural, optical and electrical properties of SnS<SUB>2</SUB> were investigated in detail. Optical properties explores the Cu doping in SnS<SUB>2</SUB> crystal lattice to result with a red-shift in absorption spectrum, which benefits visible-light absorption. Photodiodes were further fabricated by spin coating Cu doped SnS<SUB>2</SUB> nanoflakes on p-type silicon (Si). Electrical and photoelectrical parameters of Cu doped SnS<SUB>2</SUB> nanoflakes were determined by studying their impedance and current–voltage (I–V) characteristics, respectively. The diodes were found to exhibit excellent rectifying behavior and good sensitivity on par to pristine photodiodes. Impedance results identified the resistance of device to reduce considerably on Cu doping. The enhanced photoelectrical properties of the heterojunctions has been ascribed to Cu ions, which act as effective dopant and contribute to the varied carrier concentration in SnS<SUB>2</SUB>. Finally the obtained results suggest the potential of Cu-doped SnS<SUB>2</SUB> for application in photodetection and sensors applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cu doped SnS<SUB>2</SUB> nanoflakes were synthesized in hexagonal phase. </LI> <LI> Nature of charge carriers/carrier density was determined using Mott-Schottky plots. </LI> <LI> Photodiode based on Cu doped SnS<SUB>2</SUB> nanoflakes were fabricated on p-Si substrate. </LI> <LI> Photodiode revealed improved photocurrent and responsitivity values under illumination. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Disruption of a regulatory loop between DUSP1 and p53 contributes to hepatocellular carcinoma development and progression

Hao, P.P.,Li, H.,Lee, M.J.,Wang, Y.P.,Kim, J.H.,Yu, G.R.,Lee, S.Y.,Leem, S.H.,Jang, K.Y.,Kim, D.G. Elsevier Science Publishers 2015 Journal of hepatology Vol.62 No.6

Background & Aims: Altered expression of dual specificity phosphatase 1 (DUSP1) is common in tumors including hepatocellular carcinoma (HCC), and is predictive of tumor progression and poor prognosis. However, the tumor suppressive role of DUSP1 has yet to be clearly elucidated. Methods: The molecular mechanisms of tumor suppression that were investigated were induction of apoptosis, cell cycle inhibition, and regulation of p53. Additionally, the antitumor effect of DUSP1 was assessed using a mouse model. Associated signaling pathways in HCC cells and tissues were examined. Results: Downregulation of DUSP1 expression was significantly correlated with poor differentiation (p<0.001) and advanced HCC stage (p=0.023). DUSP1 expression resulted in HCC suppression and longer survival (p=0.0002) in a xenoplant mice model. DUSP1 inhibited p38 MAPK phosphorylation and subsequently suppressed HSP27 activation, resulting in enhanced p53 phosphorylation at sites S15, S20, and S46 in HCC cells. Enhanced p53 activation induced the expression of target genes p21 and p27, which are linked to cell cycle arrest and apoptosis. Thus, DUSP1 was potentially linked to p53 activation via the p38 MAPK/HSP27 pathway. Wild-type but not mutant p53 transcriptionally upregulated DUSP1 via its DNA-binding domain. DUSP1 and p53 might collaborate to suppress tumors in hepatocarcinogenesis via a positive regulatory loop. Conclusions: Our results revealed that disruption of a positive regulatory loop between DUSP1 and p53 promoted HCC development and progression, providing a rationale for a therapeutic agent that restores DUSP1 in HCC.

Structural analysis of enniatin H, I, and MK1688 and beauvericin by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and their production by Fusarium oxysporum KFCC 11363P

Song, H. -H.,Lee, H. -S.,Lee, G. -P.,Ha, S. -D.,Lee, C. Taylor Francis 2009 Food additives & contaminants. Part A. Chemistry, Vol.26 No.4

<P> The molecular structures of enniatins H, I, and MK1688 and beauvericin were investigated by liquid chromatography-tandem mass spectrometry (LC-MS/MS). MS fragmentation occurred by loss of -CO after opening of the cyclic molecule to carbonyl carbon, and cleavage of the peptide and ester bonds in the molecular structure. Fusarium oxysporum KFCC 11363P was tested for its ability to produce beauvericin and enniatins H, I, and MK1688 on five cereal substrates: rice, barley, maize, wheat, and Indian millet kernels. Furthermore, optimal conditions for the production of the four mycotoxins by the Fusarium isolate were examined on maize at four temperatures (15, 20, 25, and 30°C) and at three moisture contents (10, 20, and 40%). Large amounts of beauvericin and enniatin H were present in maize cultures at 25°C (232.4 and 196.4 µg g-1, respectively). Enniatins I and MK1688 were maximally formed at 20°C (221.5 and 180.2 µg g-1, respectively). The optimal moisture contents for the production of enniatins H (196.4 µg g-1) and MK1688 (165.6 µg g-1), were 40%.</P>

Determination of Band Alignment in the Synergistic Catalyst of Electronic Structure-Modified Graphitic Carbon Nitride-Integrated Ceria Quantum-Dot Heterojunctions for Rapid Degradation of Organic Pollutants

Sreekanth, T. V. M.,Nagajyothi, P. C.,Dillip, G. R.,Lee, Yong Rok American Chemical Society 2017 The Journal of Physical Chemistry Part C Vol.121 No.45

<P>We engineered novel heterojunction ceria (CeO<SUB>2</SUB>) QDs decorated on the surfaces of graphitic carbon nitride (g-C<SUB>3</SUB>N<SUB>4</SUB>) nanosheets by a facile in situ hydrothermal synthetic route. Using core-level/valence-band X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy, and work function measurements of the materials, we constructed the energy band alignment at the heterojunction. The band alignment has a Type-II alignment between organic (g-C<SUB>3</SUB>N<SUB>4</SUB>) and inorganic (CeO<SUB>2</SUB> QDs) semiconductors junction with valence/conduction band offsets (VBO/CBO) of −0.07/–0.31 eV. The calculated band alignment parameters of the heterojunction were compared with the experimental values of g-C<SUB>3</SUB>N<SUB>4</SUB>/CeO<SUB>2</SUB> QD composite and a new energy band diagram was proposed for the electronic structure-modified g-C<SUB>3</SUB>N<SUB>4</SUB>/CeO<SUB>2</SUB> QDs heterojunction. The newly constructed heterojunction is formed by carbon-vacancy-promoted g-C<SUB>3</SUB>N<SUB>4</SUB> coupled to lower defect-mediated (oxygen vacancies) CeO<SUB>2</SUB>, as determined by high-resolution XPS analysis. Moreover, the CeO<SUB>2</SUB> QD distribution on g-C<SUB>3</SUB>N<SUB>4</SUB> sheets using HR-TEM and the lattice parameter variations of g-C<SUB>3</SUB>N<SUB>4</SUB>/CeO<SUB>2</SUB> QDs as compared with those of pristine CeO<SUB>2</SUB> QDs from Rietveld refinement were investigated. To demonstrate the ability of the proposed heterojunction as a catalyst, we tested the catalytic activity of the composite junction for the degradation of Rhodamine B (RhB) in the presence of NaBH<SUB>4</SUB> as an example. The band alignment mechanism is useful for promoting the catalytic activity of the graphitic carbon nitride-based organic semiconductor and will attract researchers’ attention for developing new composite heterojunction catalysts for multifunctional applications.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2017/jpccck.2017.121.issue-45/acs.jpcc.7b08568/production/images/medium/jp-2017-08568k_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp7b08568'>ACS Electronic Supporting Info</A></P>

Ultrasonic-assisted synthesis of ZnTe nanostructures and their structural, electrochemical and photoelectrical properties

Ilanchezhiyan, P.,Mohan Kumar, G.,Xiao, Fu,Poongothai, S.,Madhan Kumar, A.,Siva, C.,Yuldashev, Sh.U.,Lee, D.J.,Kwon, Y.H.,Kang, T.W. Elsevier 2017 Ultrasonics sonochemistry Vol.39 No.-

<P><B>Abstract</B></P> <P>Colloidal zinc telluride (ZnTe) nanostructures were successfully processed through a simple and facile ultrasonic (sonochemical) treatment for photoelectronic applications. The particle-like morphological features, phase and nature of valence state of various metal ions existing in ZnTe were examined using electron and X-ray photoelectron spectroscopic tools. Raman spectroscopic measurements revealed the dominance of exciton-phonon coupling and occurrence of TeO<SUB>2</SUB> traces in ZnTe through the corresponding vibrations. Optical bandgap of the ZnTe suspension was estimated to be around 2.15eV, authenticating the direct allowed transitions. The <I>p</I>-type electrical conductivity and charge carrier density of ZnTe were additionally estimated from the Bode, Nyquist and Mott-Schottky type impedance plots. The photoelectrical properties of ZnTe were investigated by fabricating <I>p</I>-ZnTe/<I>n</I>-Si heterostructures and studying their corresponding current-voltage characteristics under dark and white light illumination. The diodes revealed excellent rectifying behaviour with significant increase in reverse current under illumination. The stability of the devices were also affirmed through the time-dependent photoresponse characteristics, which actually suggested the improved and effective separation of photo generated electron hole pairs across the integrated heterojunctions. The obtained results also augment the potential of sonochemically processed ZnTe for application in photo detection and sensor related functions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nanostructured ZnTe were ultrasonically processed for photoelectronics. </LI> <LI> Raman, XPS and electron microscopic tools affirmed their physico-chemical traits. </LI> <LI> Electrical properties were studied using Nyquist and Mott-Schottky plots. </LI> <LI> <I>I</I>-<I>V</I> studies augment the improved photo response in p-ZnTe/n-Si heterojunctions. </LI> </UL> </P>

MicroRNA signatures associated with immortalization of EBV‐transformed lymphoblastoid cell lines and their clinical traits

Lee, J.‐,E.,Hong, E.‐,J.,Nam, H.‐,Y.,Kim, J.‐,W.,Han, B.‐,G.,Jeon, J.‐,P. Blackwell Publishing Ltd 2011 Cell proliferation Vol.44 No.1

<P><B>Abstract</B></P><P><B>Objective: </B> MicroRNAs (miRNAs) are negative regulators of gene expression that play important roles in cell processes such as proliferation, development and differentiation. Recently, it has been reported that miRNAs are related to development of carcinogenesis. The aim of this study was to identify miRNAs associated with terminal immortalization of Epstein–Barr virus (EBV)‐transformed lymphoblastoid cell line (LCL) and associated clinical traits.</P><P><B>Material and Methods: </B> Hence, we performed miRNA microarray approach with early‐ (p6) and late‐passage (p161) LCLs.</P><P><B>Results and Conclusion: </B> Microarray data showed that nine miRNAs (miR‐20b*, miR‐28‐5p, miR‐99a, miR‐125b, miR‐151‐3p, miR‐151:9.1, miR‐216a, miR‐223* and miR‐1296) were differentially expressed in most LCLs during long‐term culture. In particular, miR‐125b was up‐regulated in all the tested late‐passage LCLs. miR‐99a, miR‐125b, miR‐216a and miR‐1296 were putative negative regulators of <I>RASGRP3</I>, <I>GPR160</I>, <I>PRKCH</I> and <I>XAF1</I>, respectively, which were found to be differentially expressed in LCLs during long‐term culture in a previous study. Linear regression analysis showed that miR‐200a and miR‐296‐3p correlated with triglyceride and HbA1C levels, respectively, suggesting that miRNA signatures of LCLs could provide information on the donor’s health. In conclusion, our study suggests that expression changes of specific miRNAs may be required for terminal immortalization of LCLs. Thus, differentially expressed miRNAs would be a potential marker for completion of cell immortalization during EBV‐mediated tumorigenesis.</P>

Modified Panax ginseng extract regulates autophagy by AMPK signaling in A549 human lung cancer cells

Yoo, H.-S.,Kim, J. M.,Jo, E.,Cho, C.-K.,Lee, S.-Y.,Kang, H. S.,Lee, M.-G.,Yang, P.-Y.,Jang, I.-S. Spandidos Publications 2017 Oncology reports Vol.37 No.6

<P>Panax ginseng has been used worldwide as a traditional medicine for the treatment of cancer and other diseases. The antiproliferative activity of ginseng has been increased after enzymatic processing of ginseng saponin, which may result in the accumulation of minor saponins, such as Rh2, Rg3, compound K and protopanaxatriol type (PPT) in modified regular ginseng extract (MRGX). In the present study, the anticancer activity and the associated mechanisms of MRGX were investigated using A549 human lung cancer cells. To elucidate the mechanisms underlying the effects of MRGX, we performed a microarray analysis of gene expression in the A549 cells. Molecular mechanisms that were associated with the anticancer activity of MRGX were studied, with a special focus on the autophagy-related multiple signaling pathways in lung cancer cells. Microarray analyses elucidated autophagy-related genes affected by MRGX. Administration of MRGX at 100 mu g/ml induced punctate cytoplasmic expression of LC3, Beclin-1 and ATG5 and increased expression of endogenous LC3-II whereas 50 mu g/ml did not inhibit the proliferation of A549 cells. Compared to the control cells, in cells treated with MRGX at 100 mu g/ml, the level of p-Akt was increased, while that of mTOR-4EBP1 was decreased. Downregulation of mTOR and 4EBP1 in the MRGX-treated cells was found not to be a p-Ulk (S757)-dependent pathway, but a p-Ulk (S317)-dependent autophagic pathway, using AMPK. These data suggest that MRGX regulates AMPK and induces autophagy in lung cancer cells.</P>

Isostructural metal-insulator transition in VO₂

Lee, D.,Chung, B.,Shi, Y.,Kim, G.-Y.,Campbell, N.,Xue, F.,Song, K.,Choi, S.-Y.,Podkaminer, J. P.,Kim, T. H.,Ryan, P. J.,Kim, J.-W.,Paudel, T. R.,Kang, J.-H.,Spinuzzi, J. W.,Tenne, D. A.,Tsymbal, E. Y. American Association for the Advancement of Scienc 2018 Science Vol.362 No.6418

<P><B>Separating structure and electrons in VO<SUB>2</SUB></B></P><P>Above 341 kelvin—not far from room temperature—bulk vanadium dioxide (VO<SUB>2</SUB>) is a metal. But as soon as the material is cooled below 341 kelvin, VO<SUB>2</SUB> turns into an insulator and, at the same time, changes its crystal structure from rutile to monoclinic. Lee <I>et al.</I> studied the peculiar behavior of a heterostructure consisting of a layer of VO<SUB>2</SUB> placed underneath a layer of the same material that has a bit less oxygen. In the VO<SUB>2</SUB> layer, the structural transition occurred at a higher temperature than the metal-insulator transition. In between those two temperatures, VO<SUB>2</SUB> was a metal with a monoclinic structure—a combination that does not occur in the absence of the adjoining oxygen-poor layer.</P><P><I>Science</I>, this issue p. 1037</P><P>The metal-insulator transition in correlated materials is usually coupled to a symmetry-lowering structural phase transition. This coupling not only complicates the understanding of the basic mechanism of this phenomenon but also limits the speed and endurance of prospective electronic devices. We demonstrate an isostructural, purely electronically driven metal-insulator transition in epitaxial heterostructures of an archetypal correlated material, vanadium dioxide. A combination of thin-film synthesis, structural and electrical characterizations, and theoretical modeling reveals that an interface interaction suppresses the electronic correlations without changing the crystal structure in this otherwise correlated insulator. This interaction stabilizes a nonequilibrium metallic phase and leads to an isostructural metal-insulator transition. This discovery will provide insights into phase transitions of correlated materials and may aid the design of device functionalities.</P>