Cytoprotective Role of the Flavonoid Quercetin in Mammalian Cells

Guang Zhi Dong,Chang Youn Kim,Wang Sik Cho,Yong Ju Shin,Kyung Ho Lee 한국유전학회 2006 Genes & Genomics Vol.28 No.3

β-Lapachone suppresses radiation-induced activation of nuclear factor-κB

Guang-Zhi Dong,Eun-Taex Oh,Hyemi Lee,Moon-Taek Park,Chang Won Song,박헌주 생화학분자생물학회 2010 Experimental and molecular medicine Vol.42 No.5

Anticancer effects of β-lapachone (β-lap) are due to generation of ROS and metabolic catastrophes as a result of NAD(P)H:quinone oxidoreductase (NQO1)-mediated futile cycling between the oxidized and reduced forms of β-lap. It has been shown that NQO1 is also essential for the TNF-induced activation of NF-κB and that β-lap suppresses the TNF-induced NF-κB activation. We investigated whether or not NQO1 is involved and β-lap suppresses the radiation-induced NF-κB activation using A549 human lung cancer cells and NQO1-knock down A549 cells (shNQO1 A549cells). Irradiation with 4 Gy markedly increased the DNA binding activity of NF-κB in A549 cells, but not in the shNQO1 A549 cells, thus demonstrating that NQO1plays a pivotal role in irradiation-induced NF-κB activation. Treatment with 10 μM β-lap for 4 h almost completely abrogated the radiation-induced increase in NF-κB activation and the transcription of NF-κB target genes such as bcl2, gadd45β and cyclinD1. Moreover, β-lap markedly suppressed the activation of IκB kinase γ (IKKγ) and the subsequent phosphorylation of IκBα, thereby inhibiting NF-κB activation. It is concluded that β-lap suppresses the radiation-induced activation of NF-κB by interrupting the involvement of NQO1 in the activation of NF-κB, thereby inhibiting the transcription of survival signals. The radiosensitization caused by β-lap may, in part, be attributed to β-lap-induced suppression of NF-κB activation.

Diarylheptanoids suppress proliferation of pancreatic cancer PANC-1 cells through modulating shh-Gli-FoxM1 pathway

Guang-zhi Dong,Ji Hye Jeong,Yu-ih Lee,이소윤,조혜원,전라옥,이화진,류재하 대한약학회 2017 Archives of Pharmacal Research Vol.40 No.4

Pancreatic cancer is one of the leading causes ofcancer, and it has the lowest 5-year survival rates. It isnecessary to develop more potent anti-pancreatic cancerdrugs to overcome the fast metastasis and resistance tosurgery, radiotherapy, chemotherapy, and combinations ofthese. We have identified several diarylheptanoids as antipancreaticcancer agents from Alpinia officinarum (lessergalangal) and Alnus japonica. These diarylheptanoidssuppressed cell proliferation and induced the cellcycle arrest of pancreatic cancer cells (PANC-1). Amongthem, the most potent compounds 1 and 7 inhibited theshh-Gli-FoxM1 pathway and their target gene expression inPANC-1 cells. Furthermore, they suppressed the expressionof the cell cycle associated genes that were rescued bythe overexpression of exogenous FoxM1. Taken together,(E)-7-(4-hydroxy-3-methoxyphenyl)-1-phenylhept-4-en-3-one (1) from Alpinia officinarum (lesser galangal) andplatyphyllenone (7) from Alnus japonica inhibit PANC-1cell proliferation by suppressing the shh-Gli-FoxM1 pathway,and they can be potential candidates for anti-pancreaticcancer drug development.

뼈모세포 초기부착에 영향을 미치는 나노수준 거칠기 칼슐포스페이트 박막 개발#

Guang Zhi Dong,고재승,Hyun-Man Kim 대한구강해부학회 2005 대한구강해부학회지 Vol.29 No.1

Surface roughness is well known to affect cellular activity. This study presents a method to fabricate nano-scale surface roughness on the surfaces of polymer, metal, glass with calcium phosphate thin film. Metastable calcium and phosphate ion solution was slowly heated to obtain calcium phosphate thin fibn. Then fresh calcium and phosphate ion solution was added to fabricate nano-scale roughness over tlùs initially forrned thin film. Various surfaces of nano- scale roughness lower than 800 nm of Ra v외ue was obtained. Initial cell adhesion was characterized over the fabricated surfaces using MC3T3-El osteoblastic cellline. Spreading of osteoblastic cell decreased according to the increase of surface roughness. Less stress fibers developed in the cells attaching to the rougher surface. Less focal contacts visualized by staining vinculin was found in the cells of irútial adhesion. All these features of the initial cell adhesion represents that less adhesion signals are generated from the rougher surface. Further study is required to evaluate the effect of these low adhesion signals on the overall cellular activitv.

Fifth Generation Communication Performance of Poly(ether ketone ketone)/Modified Montmorillonite Substrate

Guang Kui Zhou,Xiao Dong Zhi,Deng Ming Pan,Tim Hsu,Jen-taut Yeh 한국고분자학회 2022 Macromolecular Research Vol.30 No.2

Quaternary ammonium salt modified montmorillonite (QASMMT) nanoplatelets were well dispersed in poly(ether ketone ketone) (PEKK) polymers to make pleasing fifth generation (5G) substrates. Substantially smaller dielectric properties and linear thermal expansion coefficient (LCTE) were found for each PEKKa xQASMMTy film series filled with small and appropriate QASMMT loadings. The dielectric constant (εr) and dielectric loss (tan δ) values acquired for each PEKKa xQASMMTy film series reduced to a lowest value as QASMMT loadings approached 3wt%. Satisfactory εr (2.59, 2.71, and 2.80 at 1 MHz), tan δ (0.0032, 0.0038, and 0.0042 at 1 MHz) and LCTE (~36.8×10-6/℃, 38.8×10-6/℃ and 40.5×10-6/℃) for 5G communication were acquired for PEKKa 97QASMMT3 films filled with only 3wt% optimum loading of QASMMT nano-platelets. In the meantime, the onset degradation temperatures acquired for each PEKKa xQASMMTy film series increased substantially with increasing QASMMT loadings. All free volume properties, such as, the radius of the free-volume-cavity or free-volume-cavity numbers per unit volume evaluated for every PEKKa xQASMMTy film sequence enlarged to a largest value, as QASMMT loadings approached an appropriate value of 3wt%. Substantial smaller εr and tan δ were acquired for PEKKa and PEKKa xQASMMTy with larger free volume properties. Possible reasons accounting for these substantially diminished dielectric and LCTE properties of PEKKa xQASMMTy films are proposed.

The potential molecular effects of bursal septpeptide II on immune induction and antitumor activity

Guang Fang Zhou,Qing Tao Liu,Bin Zhou,Ya Feng Qiu,Xiao Dong Liu,Zhi Yong Ma,Xiu Li Feng,Rui Bing Cao,Pu Yan Chen 대한수의학회 2015 Journal of Veterinary Science Vol.16 No.3

The bursa of Fabricius (BF) is the acknowledged central humoral immune organ in birds. Bursal septpeptide II (BSP-II) is animmunomodulatory bioactive peptide isolated from BF. To understand the effects of BSP-II on immune induction, gene expression profilesof hybridoma cells treated with BSP-II were evaluated. Pathway analysis showed that regulated genes were involved in cytokine-cytokinereceptor interactions, T cell receptor signaling pathway, and pathway in cancer. It was observed that BSP-II reduced tumor cells proliferationand stimulated p53 expression. These results indicate potential mechanisms underlying the effects of the humoral immune system on immuneinduction, including antitumor activities. Our study has provided a novel insight into immunotherapeutic strategies for treating human tumors.

Efficacy and Safety of Autologous Fibroblast (FB) Seeded Biodegradable Scaffold for Rabbit Penile Girth Enlargement

( Yi Guang Wu ),( Zhe Jin ),( Zhong Cheng Xin ),( Wei Dong Song ),( Jing Peng ),( Zhi Chao Zhang ),( Bing Gao ),( Ze Long Kim ) 한국조직공학·재생의학회 2007 조직공학과 재생의학 Vol.4 No.4

The purpose of this experiment is to construct an in vitro model of rabbit penis enlargement using tissue engineering method, and to investigate the efficacy and safety of autologous fibroblast cell seeded to biodegradable scaffold and also to provide a new perspective of clinical application. We observed the growth of GFP transgenic fibroblast cell from SD mouse after transplantation with the biodegradable scaffold by fluorescence microscope. At the second hand, 160 male New Zealand rabbits were divided into four groups; Group A for control; Group B for acellular matrix implanted; Group C for scaffold implanted only; Group D for autologous cultured fibroblast seeded scaffold. Rabbit scrotal skin (4×4 mm) was detached under general anesthesia, and fibroblast (FB) was cultured and proliferated for 2weeks. Cultured cells were seeded into the scaffold and inserted on the between buck`s and dartos fascia of rabbit penis. To assess the efficacy and safety of the cells, we observed for 4months. The FB of rabbit were successfully cultured and confirmed by immunohistochemistry method. In the results of group D, dermal cell seeding group, the penile girth was significantly increased to 22.3% compared to other groups (Group A 0.3%, Group B 12.7%, Group C 14.6% and Group D 22.3%). We checked the results in 2~4 months later. We observed that moderate penile girth increase was gained using the biodegradable scaffold without other side-effects. Therefore, we carefully suggest a new guidance for penile augmentation by the tissue engineering method.

Enhanced localization for team robot navigation using compass sensor and USN

Kyoung-Dong Kim,Yoon-Gu Kim,Jinung An,Zhi-Guang Xu,Suk-Gyu Lee 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10

This paper presents an enhanced localization for team robot navigation in an unknown environment. Localization information from encoder is subject to noise resulting from friction between road surface and wheels, or the error in motor itself, in the environment. In addition, the measured error is accumulative as a robot navigates. The mobility in disaster situations is more serious because of the unstable environment. In order to solve these problems, we proposed a localization and navigation system which is comprised of an 802.15.4a protocol based communication module to measure the distance between team robots and a compass sensor to get the heading angle of every robot. The proposed method is based on a modified Kalman Filter which is adapted in our system to improve the quality of 802.15.4a protocol and compass sensor for reducing the error in measurement process. From the experimental results, we will verify better performance of the proposed system for more practical localization and navigation in the disaster sites through the team robot cooperation.

Analysis on Vegetation Restoration and Drifting-Sand Control on Sandy Degraded Grassland in Yanchi

Xia Ling,Zhi Dong,Guang Yang 한국초지조사료학회 2009 한국초지조사료학회 학술대회논문집 Vol.2009 No.08

In this paper, by investigating soil, field vegetation, and surface wind erosion status, combining in2 door analysis, the effect of vegetation recovery on sandy degraded grassland in Yanchi is studied. The results show t㏊t : after the process of protective growth, grazing rest and reseeding, the plant species and vegetation coverage are increased, and biomasses are enhanced about 66. 3214, at the same time, the effect of the measure of combining protective growth, grazing rest and reseeding is better t㏊n t㏊t of single protective growth and grazing rest, the formers biomass is 1. 54 times more t㏊n the latter. With the fixing of drifting - sand and the recovering of vegetation in demonstration area, the content s of physical clay minerals, organic matter, total N, available P and available K are all increased compared with those on drifting - sand. The thickness of wind erosion in drifting - sand control area is reduced, and the thickness is different in different vegetation recovering area, in which Artemisia sphaerocephala planting area suffers slight wind erosion; Caragana korshinskii forest present s slightly accumulating status, the accumulating thickness in Tamarix and Salix psammophila forest is the most.

Cisplatin enhances the anticancer effect of &bgr;-lapachone by upregulating NQO1

Terai, Kaoru,Dong, Guang-Zhi,Oh, Eun-Taex,Park, Moon-Taek,Gu, Yeunhwa,Song, Chang Won,Park, Heon Joo Lippincott Williams Wilkins, Inc. 2009 ANTICANCER DRUGS Vol.20 No.10

NAD(P)H:quinone oxidoreductase (NQO1) has been reported to play an important role in cell death caused by &bgr;-lapachone (&bgr;-lap), 3,4-dihydro-22,2-dimethyl-2H-naphthol[1,22b]pyran-5,6-dione. This study investigated whether cisplatin (cis-diamminedichloroplatinum) sensitizes cancer cells to &bgr;-lap by upregulating NQO1. The cytotoxicity of cisplatin and &bgr;-lap alone or in combination against FSaII fibrosarcoma cells of C3H mice in vitro was determined with a clonogenic survival assay and assessment of &ggr;-H2AX foci formation, a hallmark of DNA double-strand breaks. The cellular sensitivity to &bgr;-lap progressively increased during the 24 h after cisplatin treatment. The expression and enzymatic activity of NQO1 also increased during the 24 h after cisplatin treatment, and dicoumarol, an inhibitor of NQO1, was found to nullify the cisplatin-induced increase in &bgr;-lap sensitivity. The role of NQO1 in the cell death caused by &bgr;-lap alone or in combination with cisplatin was further elucidated using NQO1-positive and NQO1-negative MDA-MB-231 human breast cancer cells. Cisplatin increased the sensitivity of the NQO1-positive but not the NQO1-negative MDA-MB-231 cells to &bgr;-lap treatment. Combined treatment with cisplatin and &bgr;-lap suppressed the growth of FSaII tumors in the legs of C3H mice in a manner greater than additive. It is concluded that cisplatin markedly increases the sensitivity of cancer to &bgr;-lap in vitro and in vivo by upregulating NQO1.