• Title/Summary/Keyword: flow induction

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Cell Cycle Arrest by Sabaek-san is Associated with induction of Cdk Inhibitor p21 in Human Lung Cancer A549 Cells (사백산에 의한 인체 폐암세포의 G1기 성장억제기전에 관한 연구)

  • Kang Byong Ryeung;Oh Chang Sun;Lee Jae Hun;Choi Yung Hyun;Park Dong Il
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.6
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    • pp.1177-1183
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    • 2002
  • We investigated the effects of Sabaek-san (SBS) water extract on the cell proliferation of human lung carcinoma A549 cells. SBS treatment resulted in the inhibition of cell proliferation in a concentration-dependent manner. This anti-proliferative effect of A549 cells by SBS treatment was associated with morphological changes such as membrane shrinking and cell rounding up. DNA flow cytometric histograms showed that population of G1 phase of the cell cycle was increased by SBS treatment in a concentration-dependent manner. SBS treatment induced a marked accumulation of tumor suppressor p53 and a concomitant induction of cyclin-dependent kinase (Cdk) inhibitor p21WAF1/CIP, which appears to be transcriptionally upregulated and is p53 dependent. In addition, SBS treatment resulted in down-regulation of cyclooxygenase-2 (COX-2) as determined by RT-PCR analysis. The present results indicated that SBS-induced inhibition of lung cancer cell proliferation is associated with the blockage of G1/S progression the induction of apoptosis.

Vitexicarpin Induces Apoptosis in Human Prostate Carcinoma PC-3 Cells through G2/M Phase Arrest

  • Meng, Fan-Min;Yang, Jing-Bo;Yang, Chun-Hui;Jiang, Yu;Zhou, Yong-Feng;Yu, Bo;Yang, Hong
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.12
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    • pp.6369-6374
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    • 2012
  • Vitexicarpin (3', 5-dihydroxy-3, 4', 6, 7-tetramethoxyflavone), a polymethoxyflavone isolated from Viticis Fructus (Vitex rotundifolia Linne fil.), has long been used as an anti-inflammatory herb in traditional Chinese medicine. It has also been reported that vitexicarpin can inhibit the growth of various cancer cells. However, there is no report elucidating its effect on human prostate carcinoma cells. The aim of the present study was to examine the apoptotic induction activity of vitexicarpin on PC-3 cells and molecular mechanisms involved. MTT studies showed that vitexicarpin dose-dependently inhibited growth of PC-3 cells with an $IC_{50}{\sim}28.8{\mu}M$. Hoechst 33258 staining further revealed that vitexicarpin induced apoptotic cell death. The effect of vitexicarpin on PC-3 cells apoptosis was tested using prodium iodide (PI)/Annexin V-FITC double staining and flow cytometry. The results indicated that vitexicarpin induction of apoptotic cell death in PC-3 cells was accompanied by cell cycle arrest in the G2/M phase. Furthermore, our study demonstrated that vitexicarpin induction of PC-3 cell apoptosis was associated with upregulation of the proapoptotic protein Bax, and downregulation of antiapoptotic protein Bcl-2, release of Cytochrome c from mitochondria and decrease in mitochondrial membrane potential. Our findings suggested that vitexicarpin may become a potential leading drug in the therapy of prostate carcinoma.

Induction of Apoptosis and Cell Cycle Arrest by Dorema Glabrum Root Extracts in a Gastric Adenocarcinoma (AGS) Cell Line

  • Jafari, Naser;Zargar, Seyed Jalal;Yassa, Narguess;Delnavazi, Mohammad Reza
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.12
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    • pp.5189-5193
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    • 2016
  • Objective: Dorema glabrum Fisch. & C.A. Mey is a perennial plant that has several curative properties. Anti-proliferative activity of seeds of this plant has been demonstrated in a mouse fibrosarcoma cell line. The aim of the present study was to evaluate cytotoxicity of D. glabrum root extracts in a human gastric adenocarcinoma (AGS) cell line and explore mechanisms of apoptosis induction, cell cycle arrest and altered gene expression in cancer cells. Materials and Methods: The MTT assay was used to evaluate IC50 values, EB/AO staining to analyze the mode of cell death, and flow cytometry to assess the cell cycle. Quantitative real-time polymerase chain reaction (qRT-PCR) amplification was performed with apoptosis and cell cycle-related gene primers, for cyclin D1, c-myc, survivin, VEGF, Bcl-2, Bax, and caspase-3 to determine alteration of gene expression. Results: Our results showed that n-hexane and chloroform extracts had greatest toxic effects on gastric cancer cells with IC50 values of $6.4{\mu}g/ml$ and $4.6{\mu}g/ml$, respectively, after 72 h. Cell cycle analysis revealed that the population of treated cells in the G1 phase was increased in comparison to controls. Cellular morphological changes indicated induction of apoptosis. In addition, mRNA expression levels of Bax and caspase-3 were increased, and of bcl-2 survivin, VEGF, c-myc and cyclin D1 were decreased. Conclusion: Our study results suggest that D. glabrum has cytotoxic effects on AGS cells, characterized by enhanced apoptosis, reduced cell viability and arrest of cell cycling.

Up-Regulation of Interleukin-4 Receptor Expression by Interleukin-4 and CD40 Ligation via Tyrosine Kinase-Dependent Pathway

  • Kim, Hyun-Il;So, Eui-Young;Yoon, Suk-Ran;Han, Mi-Young;Lee, Choong-Eun
    • BMB Reports
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    • v.31 no.1
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    • pp.83-88
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    • 1998
  • Recently a B cell surface molecule, CD40, has emerged as a receptor mediating a co-stimulatory signal for B cell proliferation and differentiation. To investigate the mechanism of synergy between interleukin-4 (IL-4) and CD40 ligation in B cell activation, we have examined the effect of CE40 cross-linking on the IL-4 receptor expression in human B cells using anti-CE40 antibody. We observed that IL-4 and anti-CD40 both induce IL-4 receptor gene expression with a rapid kinetics resulting in a noticeable accumulation of IL-4 receptor mRNA within 4 h. While IL-4 caused a dose-dependent induction of surface IL-4 receptor expression, the inclusion of anti-CD40 in the IL-4-treated culture, further up-regulated the IL-4-induced IL-4 receptor expression as analyzed by flow cytometry. Pretreatment of B cells with inhibitors of protein tyrosine kinase (PTK) resulted in a significant inhibition of both the IL-4- and anti-CD40-induced IL-4 receptor mRNA levels, while protein kinase C (PKC) inhibitors had no effects. These results suggest that IL-4 and CD40 ligation generate B cell signals, which via PTK-dependent pathways, lead to the synergistic induction of IL-4 receptor gene expression. The rapid induction of IL-4 receptor gene expression through the tyrosine kinase-mediated signal transduction by B cell activating stimuli, would provide cells capacity for an efficient response to IL-4 in the early phase of IL-4 action, and may in part constitute the molecular basis of the reported anti-CD40 co-stimulatory effect on the IL-4-induced response.

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Comparison of Anti-cancer Potentials of Water Extracts of Bigihwan, Daechilgithang and Mokwhyangbinranghwan in Human Hepatocellular Carcinoma Cells (인체 간암세포에서 비기환(肥氣丸), 대칠기탕(大七氣湯) 및 목향빈랑환(木香檳榔丸) 열수 추출물의 항암 활성 비교)

  • Kim, Min Yeong;Lee, Hyesook;Hong, Su Hyun;Park, Cheol;Choi, Yung Hyun
    • Herbal Formula Science
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    • v.28 no.1
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    • pp.15-27
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    • 2020
  • Objectives : We selected three herb-combined remedies, Bigihwan (BGH), Daechilgitang (DCGT) and Mokwhyangbinranghwan (MHBRH), through Donguibogam text-mining analysis, and evaluated their anti-cancer effects on human hepatocellular carcinoma Hep3B cells. Methods : Cytotoxicity was assessed by an MTT assay. Apoptosis rate, autophagy and ROS level were detected by flow cytometry. The autophagy was also observed by Cyto-ID staining fluorescence microscopy. The expression of autophagy, mitophagy and pexophagy regulatory proteins was detected by Western blot analysis. Results : BGH showed the strongest effect among the three prescriptions in inhibiting Hep3B cell viability, which was associated with the induction of apoptosis and autophagy. Autophagy blockers improved cell viability and reduced apoptosis after BGH and DCGT treatments, indicating that autophagy by these prescriptions enhanced Hep3B cells against their cytotoxicity. However, MHBRH enhanced the reduction of cell viability and apoptosis by autophagy blockers. Induction of autophagy by BGH treatment was associated with mitophagy due to mitochondrial dysfunction than DCGT and MHBRH-treated cells. In addition, induction of apoptosis by BGH treatment was ROS-dependent and showed the possibility of pexophagy involvement. Conclusion : Although further studies need to be conducted to study the efficacy and mechanism of accurate anticancer activity, the present results will serve as important sources of understanding the mechanism of action of herbal remedies prescribed for liver disease as documented in Donguibogam.

Induction of Cell Death by Betulinic Acid through Induction of Apoptosis and Inhibition of Autophagic Flux in Microglia BV-2 Cells

  • Seo, Jeongbin;Jung, Juneyoung;Jang, Dae Sik;Kim, Joungmok;Kim, Jeong Hee
    • Biomolecules & Therapeutics
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    • v.25 no.6
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    • pp.618-624
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    • 2017
  • Betulinic acid (BA), a natural pentacyclic triterpene found in many medicinal plants is known to have various biological activity including tumor suppression and anti-inflammatory effects. In this study, the cell-death induction effect of BA was investigated in BV-2 microglia cells. BA was cytotoxic to BV-2 cells with $IC_{50}$ of approximately $2.0{\mu}M$. Treatment of BA resulted in a dose-dependent chromosomal DNA degradation, suggesting that these cells underwent apoptosis. Flow cytometric analysis further confirmed that BA-treated BV-2 cells showed hypodiploid DNA content. BA treatment triggered apoptosis by decreasing Bcl-2 levels, activation of capase-3 protease and cleavage of PARP. In addition, BA treatment induced the accumulation of p62 and the increase in conversion of LC3-I to LC3-II, which are important autophagic flux monitoring markers. The increase in LC3-II indicates that BA treatment induced autophagosome formation, however, accumulation of p62 represents that the downstream autophagy pathway is blocked. It is demonstrated that BA induced cell death of BV-2 cells by inducing apoptosis and inhibiting autophagic flux. These data may provide important new information towards understanding the mechanisms by which BA induce cell death in microglia BV-2 cells.

Dual Inhibition of PI3K/Akt/mTOR Pathway and Role of Autophagy in Non-Small Cell Lung Cancer Cells

  • Jeong, Eun-Hui;Choi, Hyeong-Sim;Lee, Tae-Gul;Kim, Hye-Ryoun;Kim, Cheol-Hyeon
    • Tuberculosis and Respiratory Diseases
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    • v.72 no.4
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    • pp.343-351
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    • 2012
  • Background: The phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling axis has emerged as a novel target for cancer therapy. Agents that inhibit this pathway are currently under development for lung cancer treatment. In the present study, we have tested whether dual inhibition of PI3K/Akt/mTOR signaling can lead to enahnced antitumor effects. We have also examined the role of autophagy during this process. Methods: We analyzed the combination effect of the mTOR inhibitor, temsirolimus, and the Akt inhibitor, GSK690693, on the survival of NCI-H460 and A549 non-small cell lung cancer cells. Cell proliferation was determined by MTT assay and apoptosis induction was evaluated by flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Autophagy induction was also evaluated by acridine orange staining. Changes of apoptosis or autophagy-related proteins were evaluated by western blot analysis. Results: Combination treatment with temsirolimus and GSK690693 caused synergistically increased cell death in NCI-H460 and A549 cells. This was attributable to increased induction of apoptosis. Caspase 3 activation and poly(ADP-ribose) polymerase cleavage accompanied these findings. Autophagy also increased and inhibition of autophagy resulted in increased cell death, suggesting its cytoprotective role during this process. Conclusion: Taken together, our results suggest that the combination of temsirolimus and GSK690693 could be a novel strategy for lung cancer therapy. Inhibition of autophagy could also be a promising method of enhancing the combination effect of these drugs.

A constant power and optimal power factor drive of doubly fed induction generator (이중여자 유도발전기의 정출력.최적역률 운전)

  • 이우석
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.14 no.4
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    • pp.31-38
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    • 2000
  • Wide operating range and speed control is needed for wind power generating and a Doubly Fed Induction Generator(DFIG) has good adaptivity for that purpose. This paper deals with the speed, power, and power factor control using the Grid connected DFIG in the super-synchronous speed regions, by controlling frequency and voltage fed to the rotor. Power flow of the DFIG and steady-state algebraic equations of the equivalent circuit are analyzed. The wind turbine speed and constant stator power were controlled by the rotor exciting frequency. For a normal operating region, in which the generator ratings were not exceeded, rotor exciting frequency. For a normal operating region, in which the generator ratings were not exceeded, the rotor current was either less than or equal to the rated value. Accordingly, the optimal power factor can be selected relative to the permissible rated current at the rotor coil which controls the magnitude of the injected rotor voltage to the rotor according to a given rotor frequency. Consequently, it is possible to determine the optimal drive of a DFIG for wind power generation application.

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Induction of Differentiation of the Cultured Rat Mammary Epithelial Cells by Triterpene Acids

  • Paik, Kee-Joo;Jeon, Seong-Sill;Chung, Hae-Young;Lee, Kyung-Hee;Kim, Kyu-Won;Chung, Joon-Ki;Kim, Nam-Deuk
    • Archives of Pharmacal Research
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    • v.21 no.4
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    • pp.398-405
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    • 1998
  • We investigated the effects of triterpene acids (TAs), ursolic acid (UA) and oleanolic acid (OA), on the induction of proliferation and differentiation of normal rat mammary epithelial cells (RMEC) or organoids cultured in Matrigel or primary culture system. To elucidate the effects, we tested their differentiation inducing activities with intercellular communication ability, cell cycle patterns, induction of apoptosis, and morphological differentiation in the three dimensional extracellular culture system. To study the changes of RMEC subpopulation in culture, the cultured cells were isolated, immunostained with peanut lectin (PNA) and anti-Thy-1.1 antibody and then analyzed with flow cytometry. Four different subpopulations, such as PNA and Thy-1.1 negative cells (B-), PNA positive cells (PNA+), Thy-1.1 positive cells (Thy-1.1+), PNA and Thy-1.1 positive cells (B+), were obtained and the size of each subpopulation was changed in culture with time in the presence of TAs. Intercellular communication was observed in culture for 7 days in TAs-treated cells, but not in culture for 4 days with scrape-loading dye transfer technique. $G_2$/M phase cells and the number of apoptotic population were increased in TAs-treated groups in cell cycle analyses. S phase fractions were reduced and the change of $G_1$ phase cells was not observed. The colonies with distinct multicelfular structures, such as stellate, ductal, webbed, squamous, lobulo-ductal colonies, were observed in Matrigel culture and the frequencies of each colony were changed in the presence of TAs. These results suggest that UA and OA have differentiation inducing effects on rat mammary epithelial cells in primary or in Matrigel culture.

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Effects of Tanshinone IIA from Salvia Miltiorrhiza Bunge on Induction of Apoptosis and Inhibition of Adipogenesis in 3T3-L1 Cells (단삼 유래 Tanshinone IIA가 3T3-L1 세포의 아포토시스 유도와 지방형성 억제에 미치는 영향)

  • Jeong, Seung-Il;Lee, Jong-Woo;Jang, Seon-Il
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.6
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    • pp.1409-1415
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    • 2009
  • Obesity is especially a serious health problem in industrialized countries, because it is considered to be a risk factor associated with the genesis or development of various metabolic diseases, including cardiovascular disease and type 2 diabetes mellitus. The purpose of this study was to investigate the effects of tanshinone IIA from Salvia miltiorrhiza Bunge on induction of apoptossis and inhibition of adipogenesis in in 3T3-L1 preadipocytes and adipocytes. The results demonstrated that tanshinone IIA decreased cell population growth of 3T3-L1 preadipocytes, assessed with the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] and LDH (lactate dehydrogenase) assay. Flow cytometric analysis of 3T3-L1 preadipocytes exposed to tanshinone IIA showed that apoptotic cells increased in a timeand dose-dependent manner. Treatment with tanshinone IIA decreased the number of normal cells and increased the number of apoptotic cells in a dose-dependent manner. The induction of apoptosis in 3T3-L1 preadipocytes by tanshinone IIA was mediated through the activation of caspase-3 and Bax, and then through the cleavage of PARP and the down-regulation of Bcl-2. Moreover, tanshinone IIA significantly decreased the amount of intracellular triglycerides and GPDH (glycerol-3-phosphate dehydrogenase) activity in 3T3-L1 adipocytes. Our results suggest that tanshinone IIA efficiently induces apoptosis and inhibits adipogenesis in 3T3-L1 preadipocytes and adipocytes.