• Title/Summary/Keyword: Cytotoxic protein

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IRF-1-mediated IFN-γ enhancement of TRAIL-induced apoptosis (TRAIL 유도 세포사멸에 있어서 IFN-γ의한 증가 기전 연구: IRF-1과의 관련성)

  • Park, Sang-Youel;Seol, Jae-Won;Lee, You-Jin;Kang, Seog-Jin;Kim, In-shik;Kang, Hyung-sub;Chae, Joon-seok;Cho, Jong-Hoo
    • Korean Journal of Veterinary Research
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    • v.44 no.2
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    • pp.195-200
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    • 2004
  • Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF family and potent inducer of apoptosis. TRAIL has been shown to effectively limit tumor growth in vivo without detectable cytotoxic side effects. Interferon (IFN)-${\gamma}$ often modulates the anti-cancer activities of TNF family members including TRAIL. We previously reported that IFN-${\gamma}$ enhanced TRAIL-induced Apoptosis in HeLa cells without the unknown mechanism. In this study, we investigated whether IRF-1 involves in IFN-${\gamma}$-enhanced TRAIL-induced apoptosis. We exposed HeLa cells to IFN-${\gamma}$ for 12 hours and then treated with recombinant TRAIL protein. No apoptosis was induced in cells pretreated with IFN-${\gamma}$, and TRAIL only induced 30% apoptosis after 3 hours treatment. In HeLa cells pretreated with IFN-${\gamma}$, TRAIL induced cell death to more than 75% at 3 hours, showed that IFN-${\gamma}$-pretreatment enhanced HeLa cell death to TRAIL-induced apoptosis. To investigate the functional role of IRF-1 in IFN-${\gamma}$-enhanced TRAIL-induced apoptosis, IRF-1 was overexpressed by using an adenoviral vector AdIRF-1. IRF-1 overexpression increased apoptotic cell death and significantly enhanced apoptotic cell death induced by TRAIL when infected cells were treated with TRAIL. Our findings show that IFN-${\gamma}$ enhances TRAIL-induced apoptosis by IRF-1 in HeLa cells.

Cantharidin Overcomes Imatinib Resistance by Depleting BCR-ABL in Chronic Myeloid Leukemia

  • Sun, Xiaoyan;Cai, Xueting;Yang, Jie;Chen, Jiao;Guo, Caixia;Cao, Peng
    • Molecules and Cells
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    • v.39 no.12
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    • pp.869-876
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    • 2016
  • Cantharidin (CTD) is an active compound isolated from the traditional Chinese medicine blister beetle and displayed anticancer properties against various types of cancer cells. However, little is known about its effect on human chronic myeloid leukemia (CML) cells, including imatinib-resistant CML cells. The objective of this study was to investigate whether CTD could overcome imatinib resistance in imatinib-resistant CML cells and to explore the possible underlying mechanisms associated with the effect. Our results showed that CTD strongly inhibited the growth of both imatinib-sensitive and imatinib-resistant CML cells. CTD induced cell cycle arrest at mitotic phase and triggered DNA damage in CML cells. The ATM/ATR inhibitor CGK733 abrogated CTD-induced mitotic arrest but promoted the cytotoxic effects of CTD. In addition, we demonstrated that CTD downregulated the expression of the BCR-ABL protein and suppressed its downstream signal transduction. Real-time quantitative PCR revealed that CTD inhibited BCR-ABL at transcriptional level. Knockdown of BCR-ABL increased the cell-killing effects of CTD in K562 cells. These findings indicated that CTD overcomes imatinib resistance through depletion of BCR-ABL. Taken together, CTD is an important new candidate agent for CML therapy.

Antitumor compounds from fruiting bodies of cultivated fungus of Paecilomyces japonica

  • Nama Ryu;Lim, Soon-Sung;Jung, Sang-Hoon;Cho, Sae-Yun;Shin, Kuk-Hyun
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1998.11a
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    • pp.185-185
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    • 1998
  • As part of our continuing attempts to evaluate biologically active compounds from fruiting bodies of cultivated fungus of Paecilomyces japonicus Yasuda, we conducted series of experiments on various fractions and compounds isolated by systematic fractionations. Our main efforts were concentrated on searching for compounds showing antitumor activities, which were tested on mice carrying Sarcoma-180 ascitic tumor. The antitumor activity was assessed by the life spans after these mice were administered Lp. with test compounds for consecutive 20 days. One of two pure compounds, which we have isolated to date, demonstrated significant prolongation of life span. ( Mean Survival Time: 30.3 days compared to that of control: 23.6 days). Structural analysis showed that this compound corresponds to D-mannitol. On the other hand, Ergosterol, another isolated pure compound didn't show efficient antitumor activity. We also obtained water-soluble fractions containing protein-bound polysaccharides and n-butantol fractions, which showed strong antitumor activities, 35.4(150%) and 32.1(136.0%) days of MST, respectively. In SRB assay, however, the test materials didn't show any toxic effects, but the level of acid phosphatase increased significantly when they were applied in cultured macrophage in vitro. Therefore, we concluded that antitumour activities might be attributed to immunostimulating rather than cytotoxic effects. Further experiments are underway to purify and structurally characterize new antitumour compounds from the active fractions.

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Anti-inflammatory Effects of the Methanol Extract of Polytrichum Commune via NF-κB Inactivation in RAW 264.7 Macrophage Cells

  • Cho, Woong;Park, Seung-Jae;Shin, Ji-Sun;Noh, Young-Su;Cho, Eu-Jin;Nam, Jung-Hwan;Lee, Kyung-Tae
    • Biomolecules & Therapeutics
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    • v.16 no.4
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    • pp.385-393
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    • 2008
  • As an attempt to search for bioactive natural products exerting anti-inflammatory activity, we evaluated the effects of the methanol extract of Polytrichum commune Hedw (PCM) (Polytrichaceae) on lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin $E_2$ ($PGE_2$) and pro-inflammatory cytokines release in murine macrophage cell line RAW 264.7. PCM potently inhibits the production of NO, $PGE_2$, tumor necrosis factor (TNF)-$\alpha$ and interleukin (IL)-6. Consistent with these results, PCM also concentration-dependently inhibited LPS-induced inducible NO synthase (iNOS) and cyclooxygase (COX)-2 at the protein levels, and iNOS, COX-2, TNF-$\alpha$ and IL-6 at the mRNA levels without an appreciable cytotoxic effect on RAW 264.7 macrophag cells. Furthermore, PCM inhibited LPS-induced nuclear factor-kappa B (NF-$\kappa$B) activation as determined by NF-$\kappa$B reporter gene assay, and this inhibition was associated with a decrease in the nuclear translocation of p65 and p50 NF-$\kappa$B. Taken together, these results suggest that PCM may play an anti-inflammatory role in LPS-stimulated RAW 264.7 macrophages through the inhibitory regulation of iNOS, COX-2, TNF-$\alpha$ and IL-6 via NF-$\kappa$B inactivation.

Antitumor Activity of $\alpha$-Lactalbumin on the Tumor Cells ($\alpha$-Lactalbumin의 암세포 증식 저해효과에 관한 연구)

  • 이수원;신영하;황보식
    • Food Science of Animal Resources
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    • v.22 no.1
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    • pp.72-76
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    • 2002
  • Bovine serum albumin(BSA), $\alpha$-lactalbumin($\alpha$-LA), $\beta$-lactoglobulin($\beta$-LG) and bovine immunoglobulin G (IgG) were investigated the cytotoxicity on tumor cell lines. $\alpha$-LA was showned a tendency of dose dependaent on cytotoxicity using WiDr. The growth of WiDr was inhibited 82% by 1mg/ml of $\alpha$-LA. However, IgG, BSA and $\beta$-LG were not shown the cytotoxicity on WiDr. When $\alpha$-LA was purified by using high pressure liquid chromatography(HPLC), the main component($\alpha$-LA) was eluted at 33.057 min and extremely small quantities eluted at 32.310 min. The cytotoxicity of main component (eluted at 33.057 min peak) was lower than commercial $\alpha$-LA. And the cytotoxic activity of hydrolyzed $\alpha$-LA and $\alpha$-LA treated with EDTA were lower than commercial $\alpha$-LA on tumor cells.

Enhanced Production of hCTLA4Ig by Suppressing Cell Death in Transgenic Rice Cell Suspension Cultures (형질전환 벼 현탁세포 배양에서 세포 사멸 억제를 통한 hCTLA4Ig 생산성 증대)

  • Kim, Myong-Sik;Nam, Hyung-Jin;Kim, Min-Sub;Kwon, Jun-Young;Kim, Dong-Il
    • KSBB Journal
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    • v.28 no.4
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    • pp.260-268
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    • 2013
  • Transgenic plant cell cultures are an attractive expression system for the production of industrial and pharmaceutical proteins because of their advantages in safety and low production cost. Human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) was produced and secreted when sugar was depleted in culture medium by transgenic rice cell lines (Oryza sativa L.) using RAmy3D promoter. Due to the production of the target protein by sugar depletion, concomitant occurrence of cell death is inevitable. For that reason, inhibition of cell death for enhancing productivity was necessary for the production period without energy sources. Supplementation of 0.1 mM sodium nitroprusside improved cell viability by 1.4-fold and maximum hCTLA4Ig production by 1.3-fold compared to those of control. Addition of 1 and 10 mM glutathione, N-acetylcysteine (NAC), and nicotinamide inhibited apoptotic-like programmed cell death by decreasing the activity of reactive oxygen species. Production hCTLA4Ig was enhanced 1.4-, 1.25-, and 1.15-fold with 10 mM NAC, 1 mM NAC, and 1 mM glutathione, respectively. In addition, it was found that the supplementation of NAC enhanced the cell viability.

Anti-Inflammatory Effect of Aqueous Extract of Scolopendrae Corpus in RAW 264.7 Cells (마우스 대식세포주인 RAW 264.7 세포에서 오공(蜈蚣)의 항염증 효과)

  • Jo, Il-Joo;Choi, Mee-Ok;Park, Min-Cheol;Song, Ho-Joon;Park, Sung-Joo
    • The Korea Journal of Herbology
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    • v.26 no.3
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    • pp.23-29
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    • 2011
  • Objective : The purpose of this study was to investigate the anti-inflammatory effects of aqueous extract from Scolopendrae Corpus (SC) on lipopolysaccharide (LPS)-induced inflammatory response. Methods : To evaluate the anti-inflammatory effects of SC, we examined the inflammatory mediators such as nitric oxide (NO) and pro-inflammatory cytokines (TNF-a, inteleukin (IL)-$1{\beta}$ and IL-6) on RAW 264.7 cells. We also examined molecular mechanisms such as mitogen-activated protein kinases (MAPKs) and inhibitory kappa B a ($I{\kappa}$-Ba) using western blot. Furthermore, we also investigated the effect of SC on LPS-induced endotoxin shock. Results : Extract from SC itself had not any cytotoxic effect in RAW 264.7 cells. Aqueous extract from SC inhibited LPS-induced NO production and iNOS expression. SC pre-treatment also inhibited IL-$1{\beta}$, IL-6 production in RAW 264.7 cells. To investigate inhibitory effects of SC on inflammatory mediators, activation of MAPKs was examined. SC inhibited the phosphorylation of p38 kinases (p38), c-Jun $NH_2$-terminal kinase (JNK) and also the degradation of $I{\kappa}$-$B{\alpha}$ in RAW 264.7 cells stimulated with LPS. Furthermore, SC administration reduced LPS-induced endotoxin shock. Conclusion : SC down-regulated LPS-induced production of inflammatory mediators through inhibition of activation of p38, JNK and degradation of $I{\kappa}$-$B{\alpha}$. Taken together, our results suggest that SC may be a beneficial drug against inflammatory diseases such as sepsis.

Genomic Insights and Its Comparative Analysis with Yersinia enterocolitica Reveals the Potential Virulence Determinants and Further Pathogenicity for Foodborne Outbreaks

  • Gnanasekaran, Gopalsamy;Na, Eun Jung;Chung, Han Young;Kim, Suyeon;Kim, You-Tae;Kwak, Woori;Kim, Heebal;Ryu, Sangryeol;Choi, Sang Ho;Lee, Ju-Hoon
    • Journal of Microbiology and Biotechnology
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    • v.27 no.2
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    • pp.262-270
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    • 2017
  • Yersinia enterocolitica is a well-known foodborne pathogen causing gastrointestinal infections worldwide. The strain Y. enterocolitica FORC_002 was isolated from the gill of flatfish (plaice) and its genome was sequenced. The genomic DNA consists of 4,837,317 bp with a GC content of 47.1%, and is predicted to contain 4,221 open reading frames, 81 tRNA genes, and 26 rRNA genes. Interestingly, genomic analysis revealed pathogenesis and host immune evasion-associated genes encoding guanylate cyclase (Yst), invasin (Ail and Inv), outer membrane protein (Yops), autotransporter adhesin A (YadA), RTX-like toxins, and a type III secretion system. In particular, guanylate cyclase is a heat-stable enterotoxin causing Yersinia-associated diarrhea, and RTX-like toxins are responsible for attachment to integrin on the target cell for cytotoxic action. This genome can be used to identify virulence factors that can be applied for the development of novel biomarkers for the rapid detection of this pathogen in foods.

Structures of antimicrobial peptides HP (2-20) and interactions between HP(2-20) and membrain studied by NMR spectroscopy

  • Lee, Kwang-Hwan;Lee, Dong-Gun;Park, Yoonkyung;Hahm, Kyung-Soo;Kim, Yangmee
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.68-68
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    • 2003
  • HP(2-20) (AKKVFKRLEKLEKLFSKIQNDK) derived from the N-terminus of Helicobacter pylori Ribosomal Protein L1 shows potent antimicrobial activity against bacterial, fungi and cancer cells without cytotoxic effect. In order to investigate the relationships between antimicrobial activity and the structures, several analogues have been designed and synthesized. The structures of these peptides in SDS micelles have been investigated using NMR spectroscopy and they revealed that analogue 3 has the longest, well-defined alpha-helix from Val5 to Trp19. NOESY experiments performed on HP and its analogues in nondeuterated SDS micelles show that protons in the indole ring of Trp16 are in close contact with methylene protons of SDS micelles. In order to probe the position of HP and its analogues relative to the SDS micelles, spin-labeled stearate was added. Large effects are observed for the chemical shifts and the intensities of Phe5, Glu9, Phe12, and Trp16 within the helix region by 16-doxylstearate. This result implies that 16-doxylstearate is located in the center of the micelles and the hydrophobic phase of the amphiphilic ${\alpha}$-helix is located in contact with the acyl chains of the micelles. Also, Lys3 and Lys4 at N-terminus and Lys20 at C-terminus may produce an optimal arrangement for electrostatic interactions between the sulfate head groups of the SDS and the positively charged lysyl N$\sub$3/$\^$+/. Interactions between the indole ring of Trp and the membrane, as well as the amphiphilic ${\alpha}$-helical structure of HP induced by Trp at the C-terminus may allow HP to span the lipid bilayer. These structural features are crucial for their potent antibiotic activities.

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Immuno-Modulatory Activities of Polysaccharides Separated from Jubak in Macrophage Cells (주박(酒粕)에서 분리된 다당류의 대식세포 면역조절 활성)

  • Park, Woo-Young;Sung, Nak-Yun;Byun, Eui-Hong;Oh, Kwang-Hoon;Byun, Myung-Woo;Yoo, Yung Choon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.7
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    • pp.1079-1083
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    • 2015
  • Activating macrophage cells play an important role in the host immune defense system. In this paper, immuno-modulatory activities of polysaccharides separated from Jubak (JPS) in macrophage cells were investigated. Immuno-modulatory activities were estimated based on cell proliferation, nitric oxide (NO) and cytokine production, degree of mitogen-activated protein kinases (MAPKs), and nuclear factor (NF)-${\kappa}B$ phosphorylation in RAW264.7 macrophage cells. JPS (62.5 to $250{\mu}g/mL$) did not induce a cytotoxic event. Additionally, NO and proinflammatory cytokines (tumor necrosis factor-${\alpha}$ and interleukin-6) production significantly increased in a dose-dependent manner. Similarly, phosphorylation of MAPKs and NF-${\kappa}B$ increased upon JPS treatment. Therefore, our results suggest that polysaccharides separated from Jubak can induce macrophage activation through MAPK and NF-${\kappa}B$ signaling and induction of Th1 polarization.