Serine palmitoyltransferase inhibitor myriocin induces growth inhibition of B16F10 melanoma cells through G₂/M phase arrest

Lee, Y.‐,S.,Choi, K.‐,M.,Choi, M.‐,H.,Ji, S.‐,Y.,Lee, S.,Sin, D.‐,M.,Oh, K.‐,W.,Lee, Y.‐,M.,Hong, J.‐,T.,Yun, Y.‐,P.,Yoo, H.‐,S. Blackwell Publishing Ltd 2011 Cell proliferation Vol.44 No.4

<P><B>Abstract</B></P><P><B>Objectives: </B> Melanoma is the most aggressive form of skin cancer, and it resists chemotherapy. Candidate drugs for effective anti‐cancer treatment have been sought from natural resources. Here, we have investigated anti‐proliferative activity of myriocin, serine palmitoyltransferase inhibitor, in the <I>de novo</I> sphingolipid pathway, and its mechanism in B16F10 melanoma cells.</P><P><B>Material and methods: </B> We assessed cell population growth by measuring cell numbers, DNA synthesis, cell cycle progression, and expression of cell cycle regulatory proteins. Ceramide, sphingomyelin, sphingosine and sphingosine‐1‐phosphate levels were analysed by HPLC.</P><P><B>Results: </B> Myriocin inhibited proliferation of melanoma cells and induced cell cycle arrest in the G<SUB>2</SUB>/M phase. Expressions of cdc25C, cyclin B1 and cdc2 were decreased in the cells after exposure to myriocin, while expression of p53 and p21<SUP>waf1/cip1</SUP> was increased. Levels of ceramide, sphingomyelin, sphingosine and sphingosine‐1‐phosphate in myriocin‐treated cells after 24 h were reduced by approximately 86%, 57%, 75% and 38%, respectively, compared to levels in control cells.</P><P><B>Conclusions: </B> Our results suggest that inhibition of sphingolipid synthesis by myriocin in melanoma cells may inhibit expression of cdc25C or activate expression of p53 and p21<SUP>waf1/cip1</SUP>, followed by inhibition of cyclin B1 and cdc2, resulting in G<SUB>2</SUB>/M arrest of the cell cycle and cell population growth inhibition. Thus, modulation of sphingolipid metabolism by myriocin may be a potential target of mechanism‐based therapy for this type of skin cancer.</P>

Effects of Deletion of Ca Supplement (limestone) on Growth and Beef Quality in Hanwoo Finishing Steers

Lee, C. E.,Park, N. K.,Seong, P. N.,Jin, S. H.,Park, B. Y.,Kim, K. I. 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.3

이 연구는 소 비육후기에 칼슘제(석회석)를 첨가하지 않은 사료의 급여가 성장율, 근내지방도 및 혈청 1,25-dihydroxy vitamin D_3(1,25(OH)_2D_3) 함량에 미치는 영향을 구명하기 위하여 수행되었다. 거세 한우 24두(20~24개월령)를 12두씩 대조구(석회석 2.5% 함유 농후사료)와 칼슘제 무첨가구(석회석 0%)로 배치하여 223일 동안 사료(농후사료 및 오차드그라스 건초)와 물을 무제한 급여하였고, 사양시험이 완료된 후 도축하여 육질을 평가하였다. 혈청 Ca^2+, Ca 및 P 함량에는 처리 간 차이가 없었으나 (P>0.05), 1,25(OH)_2D_3 함량은 시험 시작후 2 또는 6개월째 모두 칼슘제 무첨가구가 대조구보다 (각각 78.3 vs 51.7 또는 80.3 vs 51.1pg/mL) 높았다 (P<0.01). 칼슘제를 첨가하지 않은 사료를 급여한 비육우가 대조구보다 농후사료 섭취량은 증가하고 건초 섭취량은 감소하는 경향을 보였다. 일당증체량은 대조구보다 칼슘제 무첨가구에서 높았다(P<0.01). 등심단면적(82.8 vs 77.2㎠), 근내지방도(5.1 vs 2.2) 및 지방 함량(10.2 vs 6.7%)이 칼슘제 무첨가구가 대조구보다 높았고 (P<0.05), 수분 함량 (67.6 vs 70.4%)은 낮았다 (P<0.05). 등심 육색, pH 및 보수력에서는 처리 간 차이가 없었으나 전단력에서는 칼슘제 무첨가구에서 (2.9 vs 3.2 kg/1.27-㎝ diameter core), 약간 낮게 (P = 0.08) 나타났다. 관능평가에서는 칼슘제 무첨가구가 대조구보다 연도 (4.9 vs 4.5) 및 향미 (4.9 vs 4.6)가 약간 개선되었으나 (P<0.05) 다즙성에서는 처리간 차이가 없었다 (P<0.05) 다즙성에서는 처리간 차이가 없었다 (P<0.05). 본 연구결과는 비육후기에 칼슘제(석회석)를 첨가하지 않은 사료의 급여는 에너지 섭취의 증가 또는 1,25(OH)_2D_3의 합성 촉진을 통하여, 근내지방합성이 증가되어 성장율 및 근내지방도를 개선한다는 것을 제시하였다. A study was conducted to determine the effects of feeding a diet containing no Ca supplement (limestone) during the late finishing period on growth, marbling and serum 1,25-dihydroxy vitamin D_3 level in Korean native cattle. Twenty-four steers (20~24 mo of age) were divided into two groups of 12 each: one group assigned to a control diet (concentrates containing 2.5% limestone) and the other to a diet containing no calcium supplement. They were allowed to have free access to diets (concentrates and orchard grass hay) and water during the entire feeding period (223 d). Serum Ca^2-, Ca and P concentrations were not influenced by diets, but serum 1,25-dihydroxy vitamin D_3 concentrations determined 2 or 6 mo after the beginning of feeding the experimental diets were higher (P<0.01) in steers fed the diet without Ca supplement than in those fed the control diet (78.3 vs 51.7 and 80.3 vs 51.1 pg/mL, respectively). Steers fed the diet without Ca supplement tended to have a higher intake of concentrates, but a lower intake of hay, compared to those fed the control diet. Average daily gain was higher (P<0.05) in steers fed the diet without Ca supplement than in those fed the control diet. Feeding the diet without Ca supplement remarkably (P<0.01) increased the marbling score (5.1 vs 2.2) and the muscle (M. longissimus dorsi) fat content (10.2 vs 6.7%) with a concomitant decrease in moisture content (67.6 vs 70.4%), compared to feeding the compared to feeding the control diet. Ribeye area was increased (77.2 vs 82.8 ㎤) with the diet without Ca supplement, compared to the control diet (P<0.05). Meat color, pH and water-holding capacity in longissimus muscle were not different between the two groups. The Warner-Brazler Shear (WBS) force of the longissimus muscle was slightly (P=0.08) lower in steers fed the diet without Ca supplement than in steers fed the control diet (2.9 vs 3.2 ㎏/1.27-㎝ diameter core). Sensory evaluation showed that feeding the diet without Ca supplement slightly (P<0.05) improved tenderness (4.9 vs 4.5) and flavor (4.9 vs 4.6), compared to feeding the control diet, but juiciness was not affected by diets. Results showed that deletion of Ca supplement fro finishing diets is beneficial, increasing growth and marbling partly through an increased energy intake and induced 1,25-dihydroxy vitamin D_3 synthesis that may increase intracellular Ca^2+ concentration and in turn fat synthesis.

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>

Comparison of 90‐day case‐fatality after ischemic stroke between two different stroke outcome registries using propensity score matching analysis

Yu, K‐,H.,Hong, K‐,S.,Lee, B‐,C.,Oh, M‐,S.,Cho, Y‐,J.,Koo, J‐,S.,Park, J‐,M.,Bae, H‐,J.,Han, M‐,K.,Ju, Y‐,S.,Kang, D‐,W.,Appelros, P. Blackwell Publishing Ltd 2011 Acta neurologica Scandinavica Vol.123 No.5

<P>Yu K‐H, Hong K‐S, Lee B‐C, Oh M‐S, Cho Y‐J, Koo J‐S, Park J‐M, Bae H‐J, Han M‐K, Ju Y‐S, Kang D‐W, Appelros P, Norrving B, Terent A. Comparison of 90‐day case‐fatality after ischemic stroke between two different stroke outcome registries using propensity score matching analysis. 
Acta Neurol Scand: 2011: 123: 325–331. 
© 2010 John Wiley & Sons A/S.</P><P><B>Background – </B> It has not been clarified whether the disparity in ischemic stroke outcome between populations is caused by ethnic and geographic differences or by variations in case mix. Propensity score matching (PSM) analysis can overcome some analytical problems but is rarely used in stroke outcome research. This study was to compare the ischemic stroke case‐fatality between two PSM cohorts of Sweden and Korea.</P><P><B>Methods – </B> Prognostic variables related to baseline characteristics and stroke care were included in our PSM model. Then, we selected 7675 Swedish and 1220 Korean patients with ischemic stroke from each stroke registers and performed one‐to‐one matching based on propensity scores of each patient.</P><P><B>Results – </B> After PSM, all measured variables were well balanced in 1163 matched subjects, and the 90‐day case‐fatality was identical 6.2% (HR 0.997, 95%CI 0.905–1.099) in Sweden and Korea.</P><P><B>Conclusions – </B> No difference is found in the 90‐day case‐fatality in propensity score‐matched Swedish and Korean patients with ischemic stroke.</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>

<i>In vitro</i> inhibitory effects of Wen‐pi‐tang‐Hab‐Wu‐ling‐san on human cytochrome P450 isoforms

Lee, H. W.,Kim, D. W.,Phapale, P. B.,Lim, M. ‐,S.,Park, J.,Seo, J. J.,Park, K. M.,Park, Y. ‐,K.,Yoon, Y. ‐,R. Blackwell Publishing Ltd 2011 Journal of clinical pharmacy and therapeutics Vol.36 No.4

<P><B>Summary</B></P><P><B>What is known and Objective: </B> Although Wen‐pi‐tang‐Hab‐Wu‐ling‐san (WHW), an oriental herbal medicine, has been prescribed for the treatment of chronic renal failure (CRF) in Korean clinics, no studies regarding WHW–drug interactions had been reported. The purpose of this study was to evaluate the possibility that WHW inhibits the catalytic activities of major cytochrome P450 (CYP) isoforms.</P><P><B>Methods: </B> The abilities of various WHW extracts to inhibit phenacetin O‐de‐ethylation (CYP1A2), tolbutamide 4‐methylhydroxylation (CYP2C9), omeprazole 4′‐hydroxylation (CYP2C19), dextromethorphan O‐demethylation (CYP2D6), chlorzoxazone 6‐hydroxylation (CYP2E1) and midazolam 1‐hydroxylation (CYP3A4) were assessed using human liver microsomes.</P><P><B>Results and Discussion: </B> WHW extract at concentrations up to 100 μ<SMALL>m</SMALL> showed negligible inhibition of the six CYP isoforms tested (CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A4), with apparent IC<SUB>50</SUB> values (concentration of the inhibitor causing 50% inhibition of the original enzyme activity) of 817.5, 601.6, 521.7, 310.2, 342.8 and 487.0 μg/mL, respectively.</P><P><B>What is new and Conclusion: </B> Our <I>in vitro</I> findings suggest that WHW extract at concentrations corresponding to a clinically recommended dosage range has no notable inhibitory effects on CYP isoforms. Therefore, we believe that WHW extract may be free of drug–herb interactions when co‐administered with other medicines. However, <I>in vivo</I> human studies are needed to confirm these results.</P>

Foxp3 is a key downstream regulator of p53-mediated cellular senescence

Kim, J-E,Shin, J-S,Moon, J-H,Hong, S-W,Jung, D-J,Kim, J H,Hwang, I-Y,Shin, Y J,Gong, E-Y,Lee, D H,Kim, S-M,Lee, E Y,Kim, Y S,Kim, D,Hur, D,Kim, T W,Kim, K-p,Jin, D-H,Lee, W-J Macmillan Publishers Limited 2017 Oncogene Vol.36 No.2

<P>The downstream events and target genes of p53 in the process of senescence are not fully understood. Here, we report a novel function of the forkhead transcription factor Foxp3, which is a key player in mediating T-cell inhibitory functions, in p53-mediated cellular senescence. The overexpression of Foxp3 in mouse embryonic fibroblasts (MEFs) accelerates senescence, whereas Foxp3 knockdown leads to escape from p53-mediated senescence in p53-expressing MEFs. Consistent with these results, Foxp3 expression resulted in the induction of senescence in epithelial cancer cells, including MCF7 and HCT116 cells. Foxp3 overexpression also increased the intracellular levels of reactive oxygen species (ROS). The ROS inhibitor N-acetyl-L-cysteine rescued cells from Foxp3-expression-induced senescence. Furthermore, the elevated ROS levels that accompanied Foxp3 overexpression were paralleled by an increase in p21 expression. Knockdown of p21 in Foxp3-expressing MEFs abrogated the Foxp3-dependent increase in ROS levels, indicating that Foxp3 acts through the induction of p21 and the subsequent ROS elevation to trigger senescence. Collectively, these results suggest that Foxp3 is a downstream target of p53 that is sufficient to induce p21 expression, ROS production and p53-mediated senescence.</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>

Identification of a novel <i>FAM83H</i> mutation and microhardness of an affected molar in autosomal dominant hypocalcified amelogenesis imperfecta

Hyun, H.-K.,Lee, S.-K.,Lee, K.-E.,Kang, H.-Y.,Kim, E.-J.,Choung, P.-H.,Kim, J.-W. Blackwell Publishing Ltd 2009 International endodontic journal Vol.42 No.11

<P>Abstract</P><P>Aim </P><P>To determine the underlying molecular genetic aetiology of a family with the hypocalcified form of amelogenesis imperfecta and to investigate the hardness of the enamel and dentine of a known <I>FAM83H</I> mutation.</P><P>Methodology </P><P>Mutational screening of the <I>FAM83H</I> on the basis of candidate gene approach was performed. All exons and exon–intron boundaries was amplified and sequenced. A microhardness test was performed to measure the Vickers microhardness value.</P><P>Results </P><P>A novel nonsense mutation (c.1354C>T, p.Q452X) was identified in the last exon of <I>FAM83H</I>, which resulted in soft, uncalcified enamel. The affected enamel was extremely soft (about 17% of the normal control), but the underlying dentine was as hard as the normal control.</P><P>Conclusions </P><P>Mutational analysis revealed a novel mutation in <I>FAM83H</I> gene. Hardness of dentine was not affected by the mutation, whilst the enamel was extremely soft.</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.