• Title/Summary/Keyword: fragmentation mechanism

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Inhibition of Cell Proliferation and Induction of Apoptosis by Ethanolic Extract of Lespedeza cuneata G. Don in Human Colorectal Cancer HT-29 cells (야관문의 에탄올 추출물에 의한 대장암세포의 성장억제 및 세포사멸유도)

  • Zhao, Qian;Kim, Yeah-Un;Han, In-Hwa;Yun, Jung-Mi
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.6
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    • pp.911-917
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    • 2016
  • Lespedeza cuneata G. Don is an edible perennial herb used in traditional Korean medicine. We investigated the anti-proliferative properties and mechanism of L. cuneata extract. The ethanolic extract of L. cuneata dose-and time-dependently inhibited human colorectal cancer cell proliferation. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay was used to test the effect of the extract on proliferation of HT-29 colorectal cancer cells. The extract inhibited HT-29 cell proliferation with an $IC_{50}$ value of $554.26{\pm}8.81{\mu}g/mL$. L. cuneata extract suppressed production of pro-inflammatory cytokines interleukin-6 and tumor necrosis $factor-{\alpha}$. Apoptosis was evaluated by analysis of DNA fragmentation, poly(ADP-ribose) polymerase cleavage, caspase-3 activity, and protein expression of pro-apoptotic (Bax) and anti-apoptotic (Bcl-2). Our results demonstrated that the extract induced DNA fragmentation and characteristic morphological changes associated with apoptosis in HT-29 colorectal cancer cells. The extract also time- and dose-dependently up-regulated expression of the Bax and down-regulated expression of the Bcl-2. Furthermore, the extract dose- and time-dependently enhanced caspase-3 activity. Our findings provide evidence that L. cuneata extract may mediate its anti-proliferative effect via modulation of apoptosis.

Stress-induced biphasic ethylene and ROS biosynthesis are synergistically interacted in cell damage (스트레스에 의한 식물세포 손상에서 Biphasic Reactive Oxygen Species(ROS)와 Ethylene 생합성의 Synergism 효과)

  • Ji, Na-Ri;Park, Ky-Young
    • Journal of Plant Biotechnology
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    • v.38 no.1
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    • pp.22-29
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    • 2011
  • Although reactive oxygen species (ROS) are inevitable by-products of many redox reactions in eukaryotic cells, they play a crucial role as signaling molecules in many cellular processes for development and defense response to abiotic stresses. The biphasic ROS production which was peaked twice in a first transient phase and a second massive phase was occurred after treatment of abiotic stress such as oxidative stress, high salinity. This biphasic generation of ROS was followed by the biphasic production of stress hormone, ethylene. The mechanism of interactions between ROS and ethylene biosynthesis is studied in tobacco (Nicotiana tabaccum L.) plants under the abiotic stresses. The stress-induced ethylene production was significantly inhibited in RbohD-AS and RbohF-AS, in which antisense expression of NADPH oxidase genes was performed. The accumulation of ROS, which was determined by DAB and DCFH-DA staining, was significantly decreased after abiotic stresses in transgenic plants. The suppression of signaling with ethylene and ROS induced more tolerance in response to abiotic stress. The transgenic plants were more tolerant in MS medium supplemented with salinity stress in contrast with wild-type. Stress-induced cell damage determined by DNA fragmentation was decreased at phase II in those transgenic plants. Therefore, the first burst of ROS is more responsible for making a role as a signaling molecule during stress-induced response. These results suggested that ethylene and ROS act in a positive feedback cycle that results in mutual enhancement of ethylene and ROS production during stress-induced cell death.

Anticancer and Immune Effects of Chungpae-tang on the Metastasis of Lung Cancer Cell (청폐탕(淸肺湯)의 실험적 폐전이암에 대한 항암 및 면역효과에 관한 연구)

  • Lee Dong-Ju;Kim Myung-Dong;Kim Young-Sam;Yoo Yeong-Min;Lee Seon-Goo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.5
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    • pp.1281-1291
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    • 2005
  • Chungpae-tang is suggested to have the antitumor activity on lung cancer. This study was peformed to investigate apoptotic effect in vitro and antitumor effect and immune response after injection of B16-F10 melanoma cells and Chungpae-tang into a tail vein of C57BL/6 mice and administratition of Chungpae-tang in A549 human lung cancer cell line in vivo, respectively. Experimental studies were obtained by measuring the median survival time and cytokine expression through RT-PCR, and ELISA assay. The results were summarized as follows: 5 mg/ml of Chungpae-tang causing DNA fragmentation, caspase-3 enzyme activation, PARP fragmentation, and cytochrome c release, suggested that Chungpae-tang has in vitro apoptotic effect in A549 human lung cancer cell line in the apoptosis-induced experiment. The median survival time of the Chungpae-tang treated group was 21 days and that of control group was 22 days, suggesting that the median survival time between the Chungpae-tang treated group and the control group was not significant. Cytokine expression between the Chungpae-fang treated group and the control group was noticeable, but was not significant in the RT-PCR. In the ELISA assay, IL-2 productivity in the Chungpae-tang treated group was to increase more than that in the normal group (p<0.05) and was no significant between the Chungpae-tang treated group and the control group. $INF-\gamma$ productivity of the control group decreased more than that of the normal group (p<0.05) and that of the Chungpae-tang-treated group increased more than that of the control group (p<0.05). IL-12 productivity of the control group increased more than that of the normal group (p<0.05) and that of the Chungpae-tang-treated group decreased more than that of the control group (p<0.05) and the normal group. IL-4 productivity of the Chungpae-tang-treated group increased more than that of the normal group and the control group (p<0.05). IL-10 productivity of the Chungpae-tang-treated group increased more than that of the normal group and the control group (p<0.05). Accordingly the results show Chungpae-tang could induce apoptosis in A549 human lung cancer cell line and bring to antitumor effect and immune response against injection of B16-F10 melanoma cells into a tail vein of C57BL/6 mice but it needs more research on the precise mechanism of such effects.

Oxidative Stress in C100 Cells Induced by Combined Treatmentof Benzo(a)pyrene and/or 2,3,7,8-Tetrachlorodibenzo-p-dioxin(TCDD)

  • Bae, Mi-Ok;Choi, Kyung-Ho;Lee, Hu-Jang;Kim, Hyun-Woo;Kim, Jun-Sung;Hwang, Soon-Kyung;Park, Jin-Hong;Cho, Hyun-Sun;Cho, Myung-Haing
    • Korean Journal of Veterinary Research
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    • v.44 no.3
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    • pp.379-387
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    • 2004
  • When an organism is exposed to various toxicants chronically, reactive oxygen species(ROS) are accumulated and eventually result in several biological effects from gene expression to cell death. In the present study we investigated the oxidative damage of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin(TCDD) and/or benzo(a)pyrene (B(a)P) in C100 cells. C100 cells treated with TCDD(30 nM) and B(a)P($3{\mu}M$) underwent diverse oxidative stress as determined through thiobarbituric acid-reactive substances(TBARS) formation, DNA fragmentation, DNA single strand break(SSB) assay, immunohistochemical staining of 8-hydroxy-2'-deoxyguanosine(8-OHdG), and mRNA expressions of antioxidant enzymatic genes such as Cu/Zn-SOD gene, GPx(glutathione peroxidase 5) gene, and catalase gene. Lipid peroxidation in C100 cells was determined through measuing the formation of TBARS. For theat, the cells were pretreated with TCDD(30 nM) and/or B(a)P($3{\mu}M$) for 0.5, 1, 2 and 4 days. TBARS formation was increased in TCDD(30 nM) and B(a)P($3{\mu}M$) and mixture($30nM\;TCDD+3{\mu}M\;B(a)P$) and positive control treatment groups comparing to the controls. Mixture treatment induced more DNA fragmentation than the single treatment group at day 6. Also, SSB in all treatment groups was clearly observed when compared with the negative control group. As with the expression of antioxidant enzyme, GPx 5mRNA, B(a)P alone and mixture($30nM\;TCDD+3{\mu}M\;B(a)P$) treatment were higher comparing to those of the negative control and TCDD treatment groups. Our results suggest that exposure of C100 cells to mixture of TCDD and B(a)P leads to significant oxidative damage comparing to the exposures to the individual chemicals. Mechanisms of action are discussed. Additional studies are needed to elucidate the detailed mechanism of mixture-induced toxicity.

Pseudomonas aeruginosa Exotoxin A Induces Apoptosis in Chemoresistant YD-9 Human Oral Squamous Carcinoma Cell Line Via Accumulation of p53 and Activation of Caspases (항암제에 저항성을 가지는 YD-9 human oral squamous carcinoma cell line에서 Pseudomonas aeruginosa exotoxin A의 p53 단백질 누적과 caspase를 활성화 경로를 통해 유도된 세포자멸사)

  • Kim, Gyoo-Cheon;Gil, Young-Gi
    • Journal of Life Science
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    • v.19 no.8
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    • pp.1047-1054
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    • 2009
  • Oral squamous carcinoma (OSC) cells present resistance to chemotherapeutic agents-mediated apoptosis in the late stages of malignancy. Advances in the understanding of bacterial toxins have produced new strategies for the treatment of cancers. It was demonstrated here that Pseudomonas aeruginosa exotoxin A (PEA) significantly decreased the viability of chemoresistant YD-9 cells in the apoptosis mechanism. Apoptotic manifestations were evident through changes in nuclear morphology and generation of DNA fragmentation. PEA treatment induced caspase-3, -6 and -9 cleavage, and activation. These events preceded proteolysis of the caspase substrates poly (ADP-ribose) polymerase (PARP), DNA fragmentation factor 45 (DFF45), and lamin A in YD-9 cells. The reduction of mitochondrial membrane potential, release of cytochrome c and SmacjDlABLO from mitochondria to cytosol, andtranslocation of AlF into nucleus were shown. While p53, p21 and $14-3-3{\gamma}$ were upregulated, cyclin Band cdc2 were downregulated by PEA treatment. Taken together, PEA induces apoptosis in chemoresistant YD-9 cells via activation of caspases, mitochondrial events and regulation of cell cycle genes.

Route Optimization Scheme using Routing Protocol in Nested Mobile Networks (중첩된 이동 네트워크환경에서 동적 라우팅 프로토콜을 이용한 경로 최적화 기법)

  • Kim, Eui-Kook;Lee, Jong-Hyup
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.11
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    • pp.1966-1975
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    • 2008
  • NEMO Basic Support Protocol standardized in IETF provides the seamless communication environment to all nodes within the mobile network regardless of the network movement while the network is moving. According to the standard, when the mobile network moves outside of its home network the network can make use of the binding update message or dynamic routing protocol in order to register the mobility information into the Home Agent(HA). But because these two methods don't consider the route optimization, all packets destined to Mobile Network Nodes(MNNs) attached into the Mobile Router(MR) have to go through HAs of MRs so that they bring on the transmission delay and the waste of the bandwidth. This situation is to be worse and causes the packet fragmentation problem if MRs within the mobile network are nested. Even though there have been some researches about the route optimization to recover the problems, they have problems in the packet transmission performance side. In this paper, we propose a new scheme to improve the network performance by using a dynamic routing protocol and minimizing the number of HAs on the end-to-end path. Various performance evaluations show that the proposed mechanism gives better performance in view of the packet transmission compared to the existing schemes.

Induction of apoptosis using the mixture of fucoidan and Crepidiastrum denticulatum extract in HepG2 liver cancer cells (후코이단/이고들빼기 혼합물에 의한 HepG2 간암세포의 apoptosis 유도)

  • Se-Eun Park;Dabin Choi;Kyo-nyeo Oh;Hanjoong Kim;Hyungbum Park;Ki-Man Kim
    • Food Science and Preservation
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    • v.31 no.2
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    • pp.276-286
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    • 2024
  • In the present study, we investigated whether a mixture of fucoidan and Crepidiastrum denticulatum extract (FCE) had the potential to improve the therapeutic efficacy of cancer treatment. The results demonstrated that FCE significantly reduced cell viability and induced the release of LDH (lactate dehydrogenase) and DNA fragmentation in HepG2 cells in a dose-dependent manner. In addition, FCE treatment also increased the protein expression level of p53, the release of cytochrome c, and the loss of mitochondrial membrane potential. Moreover, FCE dose-dependently increased protein expression levels of Bax, and cleaved caspase-3 and -9. However, FCE decreased the protein expression level of Bcl-2. These results suggest that FCE inhibits cell proliferation and induces apoptosis via the mitochondrial-mediated intrinsic pathway. The present study demonstrates that FCE can be used as an anti-cancer agent for liver cancer based on apoptosis mechanism.

Gamma Irradiation Induces a Caspase-dependent Apoptotic Mechanism in Human Prostate Cancer PC-3 Cells (인간 남성호르몬 비의존형 전립선 PC-3 암세포에서 감마선의 Caspase-의존성 세포자멸사 유도 효과)

  • Chang, Jeong-Hyun;Kim, Dong-Hyun;Jeon, Gye-Rok;Kwon, Heun-Young
    • Journal of Life Science
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    • v.18 no.8
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    • pp.1042-1048
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    • 2008
  • Prostate cancer is the most predominant cancer in men and related death rate increases every year. Till date, there is no effective therapy for androgen independent prostate cancer. To investigate the mechanism for cell growth inhibition or apoptosis in human androgen independent prostate cancer PC-3 cells after gamma irradiation. The aim of this study was to examine the potential of gamma irradiation to induce apoptosis in PC-3 cells and to assess the mechanism of gamma irradiation-induced apoptosis. Five different assays were employed in this study: cell proliferation assay, morphological assessments of apoptotic cells, DNA fragmentation analysis, quantification of apoptosis by annexin V (AV) and propidium iodide (PI) staning, and western blot analysis. Cell viability was inversely related to radiation dose. DAPI-positive cells were detected 48 hr after 40 Gy radiation exposure. And nuclear morphological changes of cells were observed by gamma irradiation. DNA ladder patterns in the cells exposed to gamma-radiation were appeared at 24 hr. Also, gamma irradiation induces apoptosis of PC-3 cells via Caspase3, Bax and PARP-dependent fashion.

Design and Implementation of Autonomic De-fragmentation for File System Aging (파일 시스템 노화를 해소하기 위한 자동적인 단편화 해결 시스템의 설계와 구현)

  • Lee, Jun-Seok;Park, Hyun-Chan;Yoo, Chuck
    • The KIPS Transactions:PartA
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    • v.16A no.2
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    • pp.101-112
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    • 2009
  • Existing techniques for defragmentation of the file system need intensive disk operation for some periods at specific time such as disk defragmentation program. In this paper, for solving this problem, we design and implement the automatic and continuous defragmentation free system by distributing the disk operation. We propose the Automatic Layout Scoring(ALS) mechanism for measuring defragmentation degree and suggest the Lazy Copy mechanism that copies the defragmented data at idle time for scattering the disk operation. We search the defragmented file by Automatic Layout Scoring mechanism and then find for empty spaces for that searched file. After lazy copy of searched fils to empty space for preventing that file from being lost, the algorithm solves the defragmentation problem by updating the I-node of that file. We implement these algorithms in Linux and evaluate them for small and defragmented file to get the layout scoring. We outperform the Linux EXT2 file system by $2.4%{\sim}10.4%$ in layout scoring evaluation. And the performance of read and write for various file size is better than the EXT2 by $1%{\sim}8.5%$ for write performance and by $1.2%{\sim}7.5%$ for read performance. We suggest this system for solving the problem of defragmentation automatically without disturbing the I/O task and manual management.

Fulvestrant Does Not Have Antagonistic Effect on 17β-estradiol's Anti-proliferative Action in Cultured Chinese Hamster Ovarian Cell Line (17β-Estradiol의 CHO 세포 항 증식작용에 대한 fulvestrant의 효과)

  • Kim, Hyun Hee;Park, Hyeong Cheol;Min, Gyesik
    • Journal of Life Science
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    • v.24 no.2
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    • pp.173-180
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    • 2014
  • Estrogen can promote or inhibit cellular proliferation depending on tissue cell types and physiological condition and acts through the signal transduction pathways mediated primarily by estrogen receptors. This study examined the effects of fulvestrant (Ful), a well-known antagonist for the estrogen receptor, on the action of $17{\beta}$-estradiol (E2) with respect to the proliferation and apoptosis of Chinese hamster ovarian (CHO) cells. We used different concentrations of E2, Ful, and E2 plus Ful during different treatment durations. Treatment with 15-40 ${\mu}M$ E2 significantly inhibited proliferation in a time-dependent manner, although it had no influence in concentrations up to 1 ${\mu}M$. Interestingly, Ful at 10-40 ${\mu}M$ also inhibited cellular proliferation in both a concentration- and time-dependent manner. In addition, Ful enhanced rather than decreased the inhibitory effect on cellular proliferation by E2 in combined treatment for 10 days. Thus, Ful does not appear to have an antagonistic effect on estrogen's anti-proliferative action in CHO cells. In TUNEL assays to confirm DNA fragmentation by E2 and/or Ful, CHO cells treated with 20 ${\mu}M$ E2 showed a TUNEL-positive reaction in most DAPI-stained nuclei, and cells treated with either 40 ${\mu}M$ Ful or 40 ${\mu}M$ Ful plus 20 ${\mu}M$ E2 also exhibited a TUNEL-positive reaction but at a lower rate compared to the E2-treated cells. These results indicate that Ful does not have an antagonistic effect on estrogen's anti-proliferative action in CHO cells, suggesting that the anti-proliferative and apoptosis-related mechanism(s) through DNA fragmentation by E2 and Ful may be mediated by different signal transduction pathways.