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.

Influence of different NaOH pretreatment concentrations on saccharification and fermentation for bioethanol production from rice straw and rice husk (natural and powder)

Shabina Yeasmin,Chul-Hawn Kim,J-Y Lee,M. I. Sheikh,H-J Park,S-H Kim,G-C Kim,J-W Kim 한국펄프·종이공학회 2011 한국펄프·종이공학회 학술발표논문집 Vol.2011 No.4

The experiment was conducted to evaluate the different NaOH pretreatment concentrations (0.25%, 0.50%, 0.75%, and 1.00%) on enzymatic saccharification (with cellulase, and β-glucosidase) and fermentation (by Saccharomyces cerevisiaeKCCM 11304) for bioethanol production from rice straw and rice husk. Pretreatment of rice straw and rice husk were conducted under both natural and powder state to observe the potentiality of the biomass condition (natural and powder state). In this study, glucose and ethanol production were increased with the increase of NaOH percentage for both rice straw and rice husk (natural and powder state). For rice straw, the highest amount of glucose was obtained in 1.00% NaOH pretreatment (0.81 g g?¹ in a natural, and 0.63 g g?¹ in a powder state pretreatment). Similarly, for rice husk, the highest amount of glucose was obtained in 1.00% NaOH pretreatment (0.47 g g?¹ in a natural, and 0.46 g g?¹ lin a powder state pretreatment). However, 0.75% NaOH pretreatment resulted in glucose yield near about 1.00% NaOH pretreatment for both rice straw and rice husk (natural and powder state). On the other hand, for rice straw, the highest amount of ethanol was obtained in 1.00% NaOH pretreatment (0.36 g g?¹ in a natural, and 0.31 g g?¹ in a powder state pretreatment). In addition, for rice husk, the highest amount of ethanol was also obtained in 1.00% NaOH pretreatment (0.24 g g?¹ in a natural, and 0.23 g g?¹ in a powder state pretreatment). Moreover, 0.75% NaOH pretreatment resulted in ethanol yield near about 1.00% NaOH pretreatment for both rice straw and rice husk (natural and powder state). It was confirmed that higher amount of NaOH use is cost effective. Moreover, higher amount of glucose and ethanol was observed when powder was prepared after pretreatment. So 0.75% NaOH pretreatment in a natural state is supposed to be suitable for enzymatic saccharification and fermentation for bioethanol production.

Injective colorings of sparse graphs

Cranston, D.W.,Kim, S.J.,Yu, G. North-Holland Pub. Co ; Elsevier Science Ltd 2010 Discrete mathematics Vol.310 No.21

Let mad(G) denote the maximum average degree (over all subgraphs) of G and let χ<SUB>i</SUB>(G) denote the injective chromatic number of G. We prove that if mad(G)@?52, then χ<SUB>i</SUB>(G)@?Δ(G)+1; and if mad(G)<4219, then χ<SUB>i</SUB>(G)=Δ(G). Suppose that G is a planar graph with girth g(G) and Δ(G)>=4. We prove that if g(G)>=9, then χ<SUB>i</SUB>(G)@?Δ(G)+1; similarly, if g(G)>=13, then χ<SUB>i</SUB>(G)=Δ(G).

Simulation of single grid-based phase-contrast x-ray imaging (g-PCXI)

Lim, H.W.,Lee, H.W.,Cho, H.S.,Je, U.K.,Park, C.K.,Kim, K.S.,Kim, G.A.,Park, S.Y.,Lee, D.Y.,Park, Y.O.,Woo, T.H.,Lee, S.H.,Chung, W.H.,Kim, J.W.,Kim, J.G. Elsevier BV * North-Holland 2017 Nuclear Instruments & Methods in Physics Research. Vol. No.

<P><B>Abstract</B></P> <P>Single grid-based phase-contrast x-ray imaging (g-PCXI) technique, which was recently proposed by Wen et al. to retrieve absorption, scattering, and phase-gradient images from the raw image of the examined object, seems a practical method for phase-contrast imaging with great simplicity and minimal requirements on the setup alignment. In this work, we developed a useful simulation platform for g-PCXI and performed a simulation to demonstrate its viability. We also established a table-top setup for g-PCXI which consists of a focused-linear grid (200-lines/in strip density), an x-ray tube (100-μm focal spot size), and a flat-panel detector (48-μm pixel size) and performed a preliminary experiment with some samples to show the performance of the simulation platform. We successfully obtained phase-contrast x-ray images of much enhanced contrast from both the simulation and experiment and the simulated contract seemed similar to the experimental contrast, which shows the performance of the developed simulation platform. We expect that the simulation platform will be useful for designing an optimal g-PCXI system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> It is proposed for the single grid-based phase-contrast x-ray imaging (g-PCXI) technique. </LI> <LI> We implemented for a numerical simulation code. </LI> <LI> The preliminary experiment with several samples to compare is performed. </LI> <LI> It is expected to be useful to design an optimal g-PCXI system. </LI> </UL> </P>

표면항원 및 유전자분석에 의한 V. vulnificus균의 계통분류학적 연구(Ⅰ) : 지방산 조성 및 RAPD PCR에 의한 V. vulnificus균의 계통분류학적 연구

윤영희,김기상,신영학,이점규,오경수,유정식,이상원,이근용 국립보건연구원 1998 국립보건원보 Vol.35 No.-

The gep oncogenes, Gα₁₂ and Gα₁₃, upregulate the transforming growth factor-β1 gene

Lee, S J,Yang, J W,Cho, I J,Kim, W D,Cho, M K,Lee, C H,Kim, S G Macmillan Publishers Limited 2009 Oncogene Vol.28 No.9

Transforming growth factor-β1 (TGFβ1) plays a role in neoplastic transformation and transdifferentiation. Gα<SUB>12</SUB> and Gα<SUB>13</SUB>, referred to as the gep oncogenes, stimulate mitogenic pathways. Nonetheless, no information is available regarding their roles in the regulation of the TGFβ1 gene and the molecules linking them to gene transcription. Knockdown or knockout experiments using murine embryonic fibroblasts and hepatic stellate cells indicated that a Gα<SUB>12</SUB> and Gα<SUB>13</SUB> deficiency reduced constitutive, auto-stimulatory or thrombin-inducible TGFβ1 gene expression. In contrast, transfection of activated mutants of Gα<SUB>12</SUB> and Gα<SUB>13</SUB> enabled the knockout cells to promote TGFβ1 induction. A promoter deletion analysis suggested that activating protein 1 (AP-1) plays a role in TGFβ1 gene transactivation, which was corroborated by the observation that a deficiency of the G-proteins decreased the AP-1 activity, whereas their activation enhanced it. Moreover, mutation of the AP-1-binding site abrogated the ability of Gα<SUB>12</SUB> and Gα<SUB>13</SUB> to induce the TGFβ1 gene. Transfection of a dominant-negative mutant of Rho or Rac, but not Cdc42, prevented gene transactivation and decreased AP-1 activity downstream of Gα<SUB>12</SUB> and Gα<SUB>13</SUB>. In summary, Gα<SUB>12</SUB> and Gα<SUB>13</SUB> regulate the expression of the TGFβ1 gene through an increase in Rho/Rac-dependent AP-1 activity, implying that the G-protein-coupled receptor (GPCR)-Gα<SUB>12</SUB> pathway is involved in the TGFβ1-mediated transdifferentiation process.Oncogene (2009) 28, 1230–1240; doi:10.1038/onc.2008.488; published online 19 January 2009

Fe-Co-W 소결체와 탄소강의 레이저 용융부 결함형성에 미치는 공정변수의 영향

김성욱(S. W. Kim),윤병현(B. H. Yoon),정우광(W. G. Jung),이창희(C. H. Lee) 한국레이저가공학회 2004 한국레이저가공학회지 Vol.7 No.3

This study was performed to clarification of the formation of weld discontinuities in the dissimilar laser fusion zone. Welding parameters were beam power of 1300, 1430, 1560, and 1700 W and travel speed of 1, 1.3, and 1.7 m/min. Most cavities in the fusion zone were observed near the tip. Cavities in the fusion zone observed to be formed and grown from pores in the tip. More cavities were formed as the beam position moves to the tip side. Small cavities were decreased but large cavities were increased when the energy input increased. W content in the fusion zone was increased with heat input and as the beam position close to the tip. In the fusion zone, W content in the dendrite boundary was increased with heat input. Considering the propagation path and fracture morphology, cracks were solidification cracking, and were initiated and propagated along the dendrite boundaries. The formation of cracks might be related with the W rich μ phase which was formed in the grain boundaries and dendrite boundaries.

Introduction of virtual open chamber for testing a weather modification technique in Korea

J-W Cha,K-H Chang,M-J Lee,J-Y Jeong,J-W Jung,H-Y Yang,K-L Kim,Y-C Kim,C-H Kim,K-H Nam,M-K Suk,C-K Jung,H-Y Go,J-H Chae,G-W Lee,Y-H Cho,S-H Jung,H-M Park,Y-A Oh,J-Y Jung,B-G Kim,Y-J Kim,M-H Choi,S-D Ki 한국기상학회 2009 한국기상학회 학술대회 논문집 Vol.2009 No.4

Cytogenetic heterogeneity and their serial dynamic changes during acquisition of cytogenetic aberrations in cultured mesenchymal stem cells

Kim, J.A.,Im, K.O.,Park, S.N.,Kwon, J.S.,Kim, S.Y.,Oh, K.,Lee, D.S.,Kim, M.K.,Kim, S.W.,Jang, M.,Lee, G.,Oh, Y.M.,Lee, S.D.,Lee, D.S. Elsevier Science Publishers 2015 Mutation research Vol.777 No.-

To minimize the risk of tumorigenesis in mesenchymal stem cells (MSCs), G-banding analysis is widely used to detect chromosomal aberrations in MSCs. However, a critical limitation of G-banding is that it only reflects the status of metaphase cells, which can represent as few as 0.01% of tested cells. During routine cytogenetic testing in MSCs, we often detect chromosomal aberrations in minor cell populations. Therefore, we aimed to investigate whether such a minority of cells can expand over time or if they ultimately disappear during MSC passaging. We passaged MSCs serially while monitoring quantitative changes for each aberrant clone among heterogeneous MSCs. To investigate the cytogenetic status of interphase cells, which represent the main population, we also performed interphase FISH analysis, in combination with G-banding and telomere length determination. In human adipose tissue-derived MSCs, 4 types of chromosomal aberrations were found during culturing, and in umbilical cord MSCs, 2 types of chromosomal aberrations were observed. Sequential dynamic changes among heterogeneous aberrant clones during passaging were similar to the dynamic changes observed in cancer stem cells during disease progression. Throughout all passages, the quantitative G-banding results were inconsistent with those of the interphase FISH analysis. Interphase FISH revealed hidden aberrations in stem cell populations with normal karyotypes by G-banding analysis. We found that telomere length gradually decreased during passaging until the point at which cytogenetic aberrations appeared. The present study demonstrates that rare aberrant clones at earlier passages can become predominant clones during later passages. Considering the risk of tumorigenesis due to aberrant MSCs, we believe that our results will help to establish proper safety guidelines for MSC use. In particular, we believe it is critical to test for chromosomal aberrations using both G-banding and FISH to ensure the safety of human stem cells that are manufactured in vitro for clinical applications.

DHCP 기반 임베디드 RFID R/W 시스템 개발

황기현(G. H. Hwang),장원태(W. T Jang),심현준(H. J. Sim),김상일(S. I. Kim),이대석(D. S. Lee) 한국멀티미디어학회 2006 한국멀티미디어학회 학술발표논문집 Vol.2006 No.1

본 논문에서는 Tag 신호를 IEEE 802.11 통신 프로토콜을 통해서 데이터 및 영상처리가 가능한 PXA255 ARM 칩을 내장한 임베디드 RFID Reader/Writer 시스템과 전송된 Tag 신호를 이용하여 D/B를 검색한 후 이를 IEEE 802.11 통신 프로토콜 통해서 임베디드 시스템에 전송하는 임베다드 RFID R/W 미들웨어를 개발하였다. 개발한 임베디드 형태의 RFID R/W 시스템은 PXA255 ARM칩을 중심으로 13.56Mhz의 RFID Reader/Writer 서버와 데이터 통신을 위한 무선랜 및 TIT-LCD로 구성되어 있다. 임베디드 RFID R/W 시스템은 Tag 신호를 시리얼단자로 통해 입력받으면 이를 무선랜을 이용하여 서버로 데이터를 전송하고 다시 서버로부터 처리된 결과 이미지 데이터를 받아서 TFT-LCD화면에 표시한다. 임베디드 RFID R/W 미들웨어는 RFID R/W 취득한 Tag 신호를 임베디드 시스템에 전송하고, 임베디드 시스템은 클라이언트 소켓 프로그램을 작동시켜 IEEE 802.11 통신 프로토콜을 통해 윈도우 서버에 접속한 후 Tag 신호를 전송한다.