Gα₁₂ gep oncogene deregulation of p53-responsive microRNAs promotes epithelial–mesenchymal transition of hepatocellular carcinoma

Yang, Y M,Lee, W H,Lee, C G,An, J,Kim, E-S,Kim, S H,Lee, S-K,Lee, C H,Dhanasekaran, D N,Moon, A,Hwang, S,Lee, S J,Park, J-W,Kim, K M,Kim, S G Macmillan Publishers Limited 2015 Oncogene Vol.34 No.22

Hepatocellular carcinoma (HCC) has a poor prognosis owing to aggressive phenotype. Gα<SUB>12</SUB> gep oncogene product couples to G-protein-coupled receptors, whose ligand levels are frequently increased in tumor microenvironments. Here, we report Gα<SUB>12</SUB> overexpression in human HCC and the resultant induction of zinc-finger E-box-binding homeobox 1 (ZEB1) as mediated by microRNA deregulation. Gα<SUB>12</SUB> expression was higher in HCC than surrounding non-tumorous tissue. Transfection of Huh7 cell with an activated mutant of Gα<SUB>12</SUB> (Gα<SUB>12</SUB>QL) deregulated microRNA (miRNA or miR)-200b/a/429, -194-2/192 and -194-1/215 clusters in the miRNome. cDNA microarray analyses disclosed the targets affected by Gα<SUB>12</SUB> gene knockout. An integrative network of miRNAs and mRNA changes enabled us to predict ZEB1 as a key molecule governed by Gα<SUB>12</SUB>. Decreases of miR-200a/b, -192 and -215 by Gα<SUB>12</SUB> caused ZEB1 induction. The ability of Gα<SUB>12</SUB> to decrease p53 levels, as a result of activating protein-1 (AP-1)/c-Jun-mediated mouse double minute 2 homolog induction, contributed to transcriptional deregulation of the miRNAs. Gα<SUB>12</SUB>QL induced ZEB1 and other epithelial–mesenchymal transition markers with fibroblastoid phenotype change. Consistently, transfection with miR-200b, -192 or -215 mimic prevented the ability of Gα<SUB>12</SUB>QL to increase tumor cell migration/invasion. In xenograft studies, sustained knockdown of Gα<SUB>12</SUB> decreased the overall growth rate and average volume of tumors derived from SK-Hep1 cell (mesenchymal-typed). In HCC patients, miR-192, -215 and/or -200a were deregulated with microvascular invasion or growth advantage. In the HCC samples with higher Gα<SUB>12</SUB> level, a correlation existed in the comparison of relative changes of Gα<SUB>12</SUB> and ZEB1. In conclusion, Gα<SUB>12</SUB> overexpressed in HCC causes ZEB1 induction by deregulating p53-responsive miRNAs, which may facilitate epithelial–mesenchymal transition and growth of liver tumor. These findings highlight the significance of Gα<SUB>12</SUB> upregulation in liver tumor progression, implicating Gα<SUB>12</SUB> as an attractive therapeutic target.

Characteristic polynomial of a generalized complete product of matrices

Hwang, S.G.,Park, J.W. North Holland [etc.] 2011 Linear algebra and its applications Vol.434 No.5

For a simple graph G, let G@? denote the complement of G relative to the complete graph and let P<SUB>G</SUB>(x)=det(xI-A(G)) where A(G) denotes the adjacency matrix of G. The complete product G@?H of two simple graphs G and H is the graph obtained from G and H by joining every vertex of G to every vertex of H. In [2]P<SUB>G@?H</SUB>(x) is represented in terms of P<SUB>G</SUB>, P<SUB>G@?</SUB>, P<SUB>H</SUB> and P<SUB>H@?</SUB>. In this paper we extend the notion of complete product of simple graphs to that of generalized complete product of matrices and obtain their characteristic polynomials.

Preparation of Bimodal Porous Carbon Supported PtRu Catalysts for Fuel Cells

Hwang, S.,Park, G.-G.,Yim, S.-D.,Park, S.-H.,Yang, T.-H.,Kim, H.,Kim, C.-S. WILEY-VCH Verlag 2010 FUEL CELLS -WEINHEIM- Vol.10 No.2

<P>In this work, we synthesised the bimodal porous carbon supported electro-catalyst as a novel catalyst for fuel cells. For this purpose, the bimodal porous carbons with different pore sizes were prepared by imprinting method. Three kinds of bimodal porous carbons were fabricated by using the silica spheres with diameters of ca. 50, 100 and 300 nm and SBA-15 particle having 200–250 nm diameter and 700–900 nm length as templates. The BET surface areas of the bimoal porous carbons were determined to be 235–294 m<SUP>2</SUP> g<SUP>–1</SUP>, which are similar to that of Vulcan XC72. To evaluate the electro-catalytic activity, the PtRu nanoparticles of ca. 1.9–2.6 nm were loaded on the bimodal porous carbon supports. The PtRu/C100, synthesised by using SBA-15 and 100 nm silica sphere, had the higher electrochemical surface area (ECSA) and the lower on-set potential and showed comparable performance with the commercial catalyst.</P>

Laser 열처리를 이용한 FeMn / NiFe 박막의 자화 반전

최상대(S. D. Choi),진대현(D. H. Jin),김선욱(S. W. Kim),김영식(Y. S. Kim),이기암(K. A. Lee),이상석(S. S. Lee),황도근(D. G. Hwang) 한국자기학회 2004 韓國磁氣學會誌 Vol.14 No.6

We have studied local magnetization reversal and magnetic properties induced by Laser annealing method in the strip-patterned Ta/NiFe/FeMn/Ta and Ta/NiFe/FeMn/NiFe/Ta multilayers fabricated by ion-beam deposition. The films were exposed to the emission of the DPSS (Diode Pumped Solid State, Nd:YAG) laser under 600 G. The laser beam intensity increased up to 440 ㎽. When the laser illuminated the patterned film with the power of above 200 ㎽, the intensity of MR peak located in +87 Oe shrunk. A new MR peak was generated at -63 Oe. When the laser power is 400 ㎽, the location of positive MR peak(Hex) was changed slightly from +87 Oe to +76 Oe, and the MR ratio was decreased from 0.9% to 0.1 %. On the other hand, the new (negative) MR peak shifted from -63 Oe to -80 Oe, with the MR ratio increased up to 0.3%. As the illuminated area expanded, the intensity of opposite MR peak increased and it of negative MR peak decreased. This proved that the local reversal of exchange biasing should be realized by laser annealing.

인버터 고전압 전원공급장치를 이용한 펄스전원공급장치 연구

박성수(S.S. Park),김상희(S.H. Kim),황정연(J.Y. Hwang),남상훈(S.H. Nam),이경태(K.T. Lee),김흥근(H.G. Kim) 전력전자학회 2004 전력전자학술대회 논문집 Vol.- No.-

The klystron-modulator(K&M) system of the Pohang Light Source(PLS) had been supplying high power microwaves for the acceleration of 2.5 GeV electron beams since October 2002. There are 12 sets of K&M systems to accelerate electron beams to 2.5GeV nominal beam energy. One module of the K&M system consists of an 80 MW S-band (2856 MHZ) klystron tube and the matching 200 MW modulator. In order to obtain electron beam of the consequently stability for linac, the pulse-to-pulse beam voltage regulation is less than +/- 0.5 %. To get the reliable stability of the modulator which is less than +/- 0.5 %, a charging section is improved in a modulator which has been operated with inverter power supply.

One-pass antibacterial efficacy of bipolar air ions against aerosolized Staphylococcus epidermidis in a duct flow

Lee, S.G.,Hyun, J.,Hwa Lee, S.,Hwang, J. Pergamon Press ; Elsevier Science Ltd 2014 Journal of aerosol science Vol.69 No.-

While heating, ventilating, and air-conditioning (HVAC) systems can provide healthy and comfortable indoor environments, virtually any part of an HVAC system can support active microbial growth if sufficient nutrients are present. In this study, we introduced a methodology to enhance the one-pass antibacterial performance of air ions against aerosolized bacteria in a ventilation duct flow. Staphylococcus epidermidis (S. epidermidis) was aerosolized, mixed with the duct flow, and exposed to air ions generated by carbon fiber ionizers installed inside the duct. The S. epidermidis was then sampled at the exit of the duct and incubated to evaluate their cultivability as functions of the ion exposure time, ion concentration, and ion polarity. When the ionizers produced bipolar air ions for 2s, a high antibacterial efficiency of 85% was obtained when four ionizers were positioned both at the top and bottom walls of the duct in a configuration in which there were three changes in ion polarity (one positive ionizer, one negative ionizer, one positive ionizer, and one negative ionizer in series along the flow direction). When the ion exposure time was decreased to 0.2s, an antibacterial efficiency of 50% was realized by applying a configuration with seven changes in ion polarity. By using a scanning electron microscope (SEM), cell contraction of S. epidermidis caused by the bipolar ion treatment was observed.

Preparation of [bis(amido)-phosphine] and [amido-phosphine sulfide or oxide] hafnium and zirconium complexes for olefin polymerization

Lee, C.S.,Park, J.H.,Hwang, E.Y.,Park, G.H.,Go, M.J.,Lee, J.,Lee, B.Y. Elsevier Sequoia 2014 Journal of organometallic chemistry Vol.772 No.-

New phosphine-based bidentate ligands, 2-Me-8-Ph<SUB>2</SUB>P(X)C<SUB>9</SUB>H<SUB>8</SUB>NH (3, X = O; 4, X = S) and N-R-2-Ph<SUB>2</SUB>P(X)C<SUB>6</SUB>H<SUB>4</SUB>NH (5, R = Et, X = O; 6, R = Me, X = S; 7, R = Et, X = S) were prepared via ortho-lithiation of 1,2,3,4-tetrahydroquinaldine (2-Me-C<SUB>9</SUB>H<SUB>9</SUB>NH) and aniline derivatives (N-R-C<SUB>6</SUB>H<SUB>5</SUB>NH). Reaction of the ortho-lithiated compounds with 0.5 equiv of PhP(OPh)<SUB>2</SUB> afforded the bis(amido)-phosphine ligands (2-Me-C<SUB>9</SUB>H<SUB>8</SUB>NH-8-yl)<SUB>2</SUB>PPh (8) and (N-R-C<SUB>6</SUB>H<SUB>4</SUB>NH-2-yl)<SUB>2</SUB>PPh (9, R = Me; 10, R = Et). Using these ligands, [amido-phosphine oxide]Hf(CH<SUB>2</SUB>Ph)<SUB>3</SUB>, [amido-phosphine sulfide]Hf(CH<SUB>2</SUB>Ph)<SUB>3</SUB>, [bis(amido)-phosphine]MX<SUB>2</SUB> (M = Hf, Zr; X = CH<SUB>2</SUB>Ph, Cl, Me), and [amido-phosphine-amine]MCl<SUB>3</SUB> complexes were prepared. The molecular structures of [amido-phosphine sulfide]Hf(CH<SUB>2</SUB>Ph)<SUB>3</SUB> (13) (prepared using 6), [bis(amido)-phosphine]ZrMe<SUB>2</SUB> (22) (prepared using 8), and [amido-phosphine-amine]MCl<SUB>3</SUB> (23, M = Hf; 24, M = Zr; prepared using 9) were confirmed by X-ray crystallography. Most of the prepared complexes exhibited negligible or low activity for ethylene/1-octene copolymerization. The [amido-phosphine sulfide]Hf(CH<SUB>2</SUB>Ph)<SUB>3</SUB> complex (13) exhibited relatively high copolymerization activity (19 x 10<SUP>6</SUP> g/mol-Hf h); however, this activity was unsatisfactory compared to that of the related [amido-phosphine]Hf(CH<SUB>2</SUB>Ph)<SUB>3</SUB> complexes (up to 48 x 10<SUP>6</SUP> g/mol-Hf h).

Inflammatory lipid sphingosine-1-phosphate upregulates C-reactive protein via C/EBPβ and potentiates breast cancer progression

Kim, E-S,Cha, Y,Ham, M,Jung, J,Kim, S G,Hwang, S,Kleemann, R,Moon, A Macmillan Publishers Limited 2014 Oncogene Vol.33 No.27

A crucial role of the inflammatory lipid sphingosine-1-phosphate (S1P) in breast cancer aggressiveness has been reported. Recent clinical studies have suggested that C-reactive protein (CRP) has a role in breast cancer development. However, limited information is available on the molecular basis for the expression of CRP and its functional significance in breast cell invasion. The present study aimed to elucidate the molecular link between S1P and CRP during the invasive process of breast epithelial cells. This is the first report showing that transcription of CRP was markedly activated by S1P in breast cells. Our data suggest that not only S1P treatment but also the endogenously produced S1P may upregulate CRP in breast carcinoma cells. Transcription factors CCAAT/enhancer-binding protein beta and c-fos were required for S1P-induced CRP expression. Coupling of S1P<SUB>3</SUB> to heterotrimeric G<SUB>αq</SUB> triggered the expression of CRP, utilizing signaling pathways involving reactive oxygen species (ROS), Ca<SUP>2+</SUP> and extracellular signal-related kinases (ERKs). S1P-induced CRP expression was crucial for the transcriptional activation of matrix metalloproteinase-9 through ERKs, ROS and c-fos, leading to breast cell invasion. Using a xenograft mice tumor model, we demonstrated that S1P induced CRP expression both in vitro and in vivo. Taken together, our findings have revealed a molecular basis for S1P-induced transcriptional activation of CRP and its functional significance in the acquisition of the invasive phenotype of human breast epithelial cells under inflammatory conditions. Our findings may provide useful information on the identification of useful therapeutic targets for inflammatory breast cancer.

부교감 신경 자극에 의한 심방세동 시뮬레이션 모델

이현승(H.S. Lee),권순성(S.S. Kwon),박진서(J.S. Park),지윤철(Y.C. Jee),황민기(M.G. Hwang),박희남(H.N. Pak),심은보(E.B. Shim) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

To represent atrial fibrillation (AF) we use the bi-domain model coupled with the Courtmanche model of human atrial cell and simulate the 3D electric waves on left atrial surface. S1-S2 stimulation protocol is applied to induce AF in the model. We obtained patient-specific geometries of left atrium (LA) from CT data and constructed three-dimensional (3D) simulation models. The purpose of this study is to investigate the effect of nerve activity on electric wave propagation in AF. In the cell model, we add acetycoline-activated potassium current to reflect the nerve effect of ganglionated plexus. Parasympathetic actions are formulated based on the experimental results of acetylcholine effects in patch-clamp studies. Computed results show that ach-activated potassium current by parasympathetic stimuls induces maintained AF waves than control condition.

Progress in the development of heating systems towards long pulse operation for KSTAR

Kwak, J.G.,Bae, Y.D.,Chang, D.H.,Chang, D.S.,Hong, B.G.,Hwang, C.K.,In, S.R.,Jeong, S.H.,Jin, J.T.,Jung, K.S.,Kim, B.R.,Kim, J.,Kim, S.K.,Kim, T.S.,Lee, D.W.,Lee, K.W.,Oh, B.H.,Seo, C.S.,Seo, M.S.,Yoo International Atomic Energy Agency 2007 Nuclear fusion Vol.47 No.5

<P>Construction of the Korea superconducting tokamak advanced research (KSTAR) tokamak is in its final phase. For the long-pulse KSTAR discharges, the ion cyclotron range of frequencies (ICRF) and neutral beam injection (NBI) heating systems are expected to play important roles through a selective heating of ions and electrons, control of the plasma pressure and current profiles, a core fuelling and beam diagnostics for the KSTAR. In addition, the ICRF system is expected to be used for possible discharge cleaning and assisting in the tokamak startup. In this paper, the recent progress in the development of the ICRF and the NBI heating systems is described. The four-strap ICRF antenna has been successfully tested for a voltage up to 41 kV for a pulse length of 300 s (to 46 kV for 20 s) in a test chamber. A prototype KSTAR NBI system has been developed. At present, the system has successfully produced a 1 MW beam power for 200 s and a 3.5 MW output beam power for 4 s.</P>