• Title/Summary/Keyword: synergistic inhibition

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Enhanced Macrophage Antitumor Effects of Protein A in Combination with $IFN-{\Upsilon}$

  • Pyo, Sun-Kneung;Rhee, Dong-Kwon
    • Archives of Pharmacal Research
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    • v.22 no.3
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    • pp.267-273
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    • 1999
  • In this study we examined the potential for the synergistic augmentation of the antitumor activity of inflammatory mouse peritoneal macrophages by stimulation with protein A combined with $IFN-\gamma$. The moderate augmentative effect induced by preincubation with protein A was demonstrated to be concentration-dependent, whereas IFN-, had a very low activating effect. Following preincubation with both protein A and $IFN-\gamma$, a marked enhancement of macrophage activity was noted. In addition, based on the utilization of neutralizing antibody to TNF-$\alpha$ or the inhibition of NO Production, TNF-$\alpha$ and NO were proven to be involved as mediators during the activation of tumoricidal macrophages by protein A in combination with $IFN-\gamma$. We also demonstrated that supernatants from macrophages treated with protein A plus $IFN-\gamma$ contained both TNF-$\alpha$ and NO at markedly increased levels. Thus, tumor cell lysis in the combined system was mediated via TNF-$\alpha$ or NO. These results demonstrate the synergistic effects on mouse pertioneal macrophage function of protein A in combination with $IFN-\gamma$ and suggest that combinations of such agents may serve as the basis for future in vivo immunotherapy.

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Synergistic Enhancement of Paclitaxel-Induced Inhibition of Cell Growth by Metformin in Melanoma Cells

  • Ko, Gihyun;Kim, Taehyung;Ko, Eunjeong;Park, Deokbae;Lee, Youngki
    • Development and Reproduction
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    • v.23 no.2
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    • pp.119-128
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    • 2019
  • Melanoma is one of the most aggressive and treatment-resistant malignancies. Antidiabetic drug metformin has been reported to inhibit cell proliferation and metastasis in many cancers, including melanoma. Metformin suppresses the mammalian target of rapamycin (mTOR) and our previous study showed that it also inhibits the activity of extracellular signal-regulated kinase (ERK). Paclitaxel is currently prescribed for treatment of melanoma. However, paclitaxel induced the activation of ERK/mitogen-activated protein kinase (MAPK) pathway, a cell signaling pathway implicated in cell survival and proliferation. Therefore, we reasoned that combined treatment of paclitaxel with metformin could be more effective in the suppression of cell proliferation than treatment of paclitaxel alone. Here, we investigated the combinatory effect of paclitaxel and metformin on the cell survival in SK-MEL-28 melanoma cell line. Our study shows that the combination of paclitaxel and metformin has synergistic effect on cell survival and suppresses the expression of proteins involved in cancer metastasis. These findings suggest that the combination of paclitaxel and metformin can be a possible therapeutic option for treatment of melanoma.

Specific Expression of Interferon-γ Induced by Synergistic Activation Mediator-Derived Systems Activates Innate Immunity and Inhibits Tumorigenesis

  • Liu, Shuai;Yu, Xiao;Wang, Qiankun;Liu, Zhepeng;Xiao, Qiaoqiao;Hou, Panpan;Hu, Ying;Hou, Wei;Yang, Zhanqiu;Guo, Deyin;Chen, Shuliang
    • Journal of Microbiology and Biotechnology
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    • v.27 no.10
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    • pp.1855-1866
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    • 2017
  • The synergistic activation mediator (SAM) system can robustly activate endogenous gene expression by a single-guide RNA. This transcriptional modulation has been shown to enhance gene promoter activity and leads to epigenetic changes. Human $interferon-{\gamma}$ is a common natural glycoprotein involved in antiviral effects and inhibition of cancer cell growth. Large quantities of high-purity $interferon-{\gamma}$ are important for medical research and clinical therapy. To investigate the possibility of employing the SAM system to enhance endogenous human $interferon-{\gamma}$ with normal function in innate immunity, we designed 10 single-guide RNAs that target 200 bp upstream of the transcription start sites of the $interferon-{\gamma}$ genome, which could significantly activate the $interferon-{\gamma}$ promoter reporter. We confirmed that the system can effectively and highly activate $interferon-{\gamma}$ expression in several humanized cell lines. Moreover, we found that the $interferon-{\gamma}$ induced by the SAM system could inhibit tumorigenesis. Taken together, our results reveal that the SAM system can modulate epigenetic traits of non-immune cells through activating $interferon-{\gamma}$ expression and triggering JAK-STAT signaling pathways. Thus, this strategy could offer a novel approach to inhibit tumorigenesis without using exogenous $interferon-{\gamma}$.

In-Vitro, Anti-Bacterial Activities of Aqueous Extracts of Acacia catechu (L.F.)Willd, Castanea sativa, Ephedra sinica stapf and shilajita mumiyo Against Gram Positive and Gram Negative Bacteria

  • Dashtdar, Mehrab;Dashtdar, Mohammad Reza;Dashtdar, Babak;shirazi, Mohammad khabaz;Khan, Saeed Ahmad
    • Journal of Pharmacopuncture
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    • v.16 no.2
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    • pp.15-22
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    • 2013
  • Objective: Evaluations of the in-vitro anti-bacterial activities of aqueous extracts of Acacia catechu (L.F.)Willd, Castanea sativa, Ephedra sinica stapf and Shilajita mumiyo against gram-positive bacteria (Staphylococcus aureus, Streptococcus pneumonia) and gram-negative bacteria (Escherichia coli, klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa) are reasonable since these ethnomedicinal plants have been used in Persian folk medicine for treating skin diseases, venereal diseases, respiratory problems and nervous disorders for ages. Methods: The well diffusion method (KB testing) with a concentration of $250{\mu}g/disc$ was used for evaluating the minimal inhibitory concentrations (MIC). Maximum synergistic effects of different combinations of components were also observed. Results: A particular combination of Acacia catechu (L.F.) Willd, Castanea sativa, Ephedra sinica stapf and shilajita mumiyo extracts possesses an outstanding anti-bacterial activity. It's inhibiting effect on microorganisms is significant when compared to the control group (P<0.05). Staphylococcus aureus was the most sensitive microorganism. The highest anti-bacterial activity against gram-positive bacteria (Staphylococcus aureus, Streptococcus pneumonia) or gram-negative bacteria (Escherichia coli, Klebsiella pneumonia, Proteus mirabilis, and Pseudomonas aeruginosa) was exerted by formula number 2 (table 1). Conclusion: The results reveal the presence of anti-bacterial activities of Acacia catechu, Castanea sativa husk, Ephedra sp. and Mumiyo against gram-positive and gram-negative bacteria. Synergistic effects in a combined formula, especially in formula number 2 (ASLAN$^{(R)}$) can lead to potential sources of new antiseptic agents for treatment of acute or chronic skin ulcers. These results considering the significant anti-bacterial effect of the present formulation, support ethnopharmacological uses against diarrheal and venereal diseases and demonstrate use of these plants to treat infectious diseases.

Synergistic inhibition of mesothelioma cell growth by the combination of clofarabine and resveratrol involves Nrf2 downregulation

  • Lee, Yoon-Jin;Im, Jae-Hyuk;Lee, David M.;Park, Ji-Sung;Won, Seong Youn;Cho, Moon-Kyun;Nam, Hae-Seon;Lee, Yong-Jin;Lee, Sang-Han
    • BMB Reports
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    • v.45 no.11
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    • pp.647-652
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    • 2012
  • We previously reported that MSTO-211H cells have a higher capacity to regulate Nrf2 activation in response to changes in the cellular redox environment. To further characterize its biological significance, the response of Nrf2, a transcription factor that regulates ARE-containing genes, on the synergistic cytotoxic effect of clofarabine and resveratrol was investigated in mesothelioma cells. The combination treatment showed a marked growth-inhibitory effect, which was accompanied by suppression of Nrf2 activation and decreased expression of heme oxygenase-1 (HO-1). While transient overexpression of Nrf2 conferred protection against the cytotoxicity caused by their combination, knockdown of Nrf2 expression using siRNA enhanced their cytotoxic effect. Pretreatment with Ly294002, a PI3K inhibitor, augmented the decrease in HO-1 level by their combination, whereas no obvious changes were observed in Nrf2 levels. Altogether, these results suggest that the synergistic cytotoxic effect of clofarabine and resveratrol was mediated, at least in part, through suppression of Nrf2 signaling.

Algicidal Characteristics of Cashew Nut Oil against Microalgae and Development of its Mixtures with Synergistic Effects (미세조류에 대한 캐슈넛 오일의 살조활성특징과 상승효과를 가지는 혼합처리제 탐색)

  • Kwak, Hwa Sook;Kim, Bo Gwan;Kim, Jin-Seog
    • Weed & Turfgrass Science
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    • v.5 no.3
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    • pp.136-143
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    • 2016
  • This study was conducted to investigate the algicidal characteristics of cashew nut oil (CNO) and to develop CNO mixtures with other compounds having synergistic effects on the growth inhibition against a blue-green alga, Microcystis aeruginosa. Among tested CNOs, CNO with higher anacardic acid contents (Ana-A) exhibited the best algicidal activity against M. aeruginosa. Ana-A showed broad algicidal spectrum with particular greater activity against blue-green algae than green algae. Ana-A showed the greatest activity against to Oscillatoria tenuis ($IC_{50}=0.19{\mu}g\;mL^{-1}$) among the tested blue-green algae and to Chlorella vulgaris ($IC_{50}=4.54{\mu}g\;mL^{-1}$) among the tested green algae, respectively. In a mixture experiment to evaluate a chemical interaction in M. aeruginosa control, Ana-A showed a strong synergistic effect with MSB and menadione, mild synergistic effect with citric acid, and additive effect with chryspophanol, copper sulfate and quinoclamine. Taken together, our results suggest that CNO containing higher anacardic acid can be used as an eco-friendly natural algicide for selective control of blue-green algae such as M. aeruginosa and O. tenuis through an optimization of application rate and in combination with synergists such as MSB and menadione.

Synergistic antitumor activity of a DLL4/VEGF bispecific therapeutic antibody in combination with irinotecan in gastric cancer

  • Kim, Da-Hyun;Lee, Seul;Kang, Hyeok Gu;Park, Hyun-Woo;Lee, Han-Woong;Kim, Dongin;Yoem, Dong-Hoon;Ahn, Jin-Hyung;Ha, Eunsin;You, Weon-Kyoo;Lee, Sang Hoon;Kim, Seok-Jun;Chun, Kyung-Hee
    • BMB Reports
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    • v.53 no.10
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    • pp.533-538
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    • 2020
  • Notch signaling has been identified as a critical pathway in gastric cancer (GC) progression and metastasis, and inhibition of Delta-like ligand 4 (DLL4), a Notch ligand, is suggested as a potent therapeutic approach for GC. Expression of both DLL4 and vascular endothelial growth factor receptor 2 (VEGFR2) was similar in the malignant tissues of GC patients. We focused on vascular endothelial growth factor (VEGF), a known angiogenesis regulator and activator of DLL4. Here, we used ABL001, a DLL4/VEGF bispecific therapeutic antibody, and investigated its therapeutic effect in GC. Treatment with human DLL4 therapeutic antibody (anti-hDLL4) or ABL001 slightly reduced GC cell growth in monolayer culture; however, they significantly inhibited cell growth in 3D-culture, suggesting a reduction in the cancer stem cell population. Treatment with anti-hDLL4 or ABL001 also decreased GC cell migration and invasion. Moreover, the combined treatment of irinotecan with anti-hDLL4 or ABL001 showed synergistic antitumor activity. Both combination treatments further reduced cell growth in 3D-culture as well as cell invasion. Interestingly, the combination treatment of ABL001 with irinotecan synergistically reduced the GC burden in both xenograft and orthotopic mouse models. Collectively, DLL4 inhibition significantly decreased cell motility and stem-like phenotype and the combination treatment of DLL4/VEGF bispecific therapeutic antibody with irinotecan synergistically reduced the GC burden in mouse models. Our data suggest that ABL001 potentially represents a potent agent in GC therapy. Further biochemical and pre-clinical studies are needed for its application in the clinic.

Anti-Oxidative and Anti-Obesity Activities of Tetrapanax papyriferus and Siegesbeckia pubescens Extracts and their Synergistic Anti-Obesity Effects (통초.희렴 추출물의 항산화.항비만 활성 및 혼합물의 항비만 시너지 효과)

  • Park, Jung Ae;Jin, Kyong-Suk;Lee, Ji Young;Kwon, Hyun Ju;Kim, Byung Woo
    • Microbiology and Biotechnology Letters
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    • v.41 no.3
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    • pp.341-349
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    • 2013
  • In this study, the anti-oxidative and anti-obesity activities of two medicinal herb extracts, Tetrapanax papyriferus (TP) and Siegesbeckia pubescens (SP), were evaluated using DPPH radical scavenging activity assay, lipase enzyme inhibition assay, and the cell culture model system. Both methanol extracts of TP and SP showed DPPH radical scavenging activities dose-dependently, and the $IC_{50}$ of DPPH radical scavenging activities of the two medicinal herbs were 65.23 and 47.79 ${\mu}g/ml$, respectively. Furthermore, both extracts suppressed effectively lipase enzyme activity dose-dependently. Moreover, TP and SP extracts significantly suppressed adipocyte differentiation, lipid accumulation, triglyceride (TG) contents on 3T3-L1 preadipocytes in a dose-dependent manner without cytotoxicity. Their anti-obesity effect was modulated by cytidine-cytidine-adenosine-adenosine-thymidine (CCAAT)/enhancer binding proteins ${\alpha}$ ($C/EBP{\alpha}$), $C/EBP{\beta}$ and peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$) gene and protein expressions. Furthermore, TP and SP possessed a synergistic effect on anti-obesity activity. The identification of the active compounds that confer the anti-obesity activity of TP and SP might be needed.

Schedule-Dependent Effect of Epigallocatechin-3-Gallate (EGCG) with Paclitaxel on H460 Cells

  • Park, Sunghoon;Kim, Joo-Hee;Hwang, Yong Il;Jung, Ki-Suck;Jang, Young Sook;Jang, Seung Hun
    • Tuberculosis and Respiratory Diseases
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    • v.76 no.3
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    • pp.114-119
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    • 2014
  • Background: Epigallocatechin-3-gallate (EGCG), a major biologically active component of green tea, has anti-cancer activity in human and animal models. We investigated the schedule-dependent effect of EGCG and paclitaxel on growth of NCI-H460 non-small cell lung cancer cells. Methods: To investigate the combined effect of EGCG (E) and paclitaxel (P), combination indices (CIs) were calculated, and cell cycle analysis was performed. For the effect on cell apoptosis, western blot analysis was also performed. Results: CI analysis demonstrated that both concurrent and sequential E ${\rightarrow}$ P treatments had antagonistic effects (CIs >1.0), but sequential P ${\rightarrow}$ E had synergistic effects (CIs <1.0), on the growth inhibition of NCI-H460 cells. In the cell cycle analysis, although paclitaxel induced $G_2/M$ cell cycle arrest and increased the sub-G1 fraction, concurrent EGCG and paclitaxel treatments did not have any additive or synergistic effects compared with the paclitaxel treatment alone. However, western blot analysis demonstrated that sequential P ${\rightarrow}$ E treatment decreased the expression of Bcl-2 and procaspase-3 and increased poly(ADP-ribose) polymerase (PARP) cleavage; while minimal effects were seen with concurrent or sequential E ${\rightarrow}$ P treatments. Conclusion: Concurrent or sequential E ${\rightarrow}$ P treatment had opposite effects to P ${\rightarrow}$ E treatment, where P ${\rightarrow}$ E treatment showed a synergistic effect on growth inhibition of NCI-H460 cells by inducing apoptosis. Thus, the efficacy of EGCG and paclitaxel combination treatment seems to be schedule-dependent.

Synergistic antitumor activity of ST1571 and camptothecin in human cancer cells (Camptothecin 에 의한 ST1571 의 항암 활성 증강)

  • Kim, Mi-Ju;Lee, Sang-Min;Bae, Jae-Ho;Chung, Byung-Seon;Kang, Chi-Dug;Kim, Sun-Hee
    • Journal of Life Science
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    • v.17 no.6 s.86
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    • pp.748-755
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    • 2007
  • The in vitro activity of ST1571, an inhibitor of the Abl group of protein-tyrosine kinases, alone or in combination with camptothecin (CPT), a specific topoisomerase I inhibitor, was evaluated against human cancer cells with different metastatic capacity and drug resistance potency. These cell lines showed different sensitivity to ST157 on growth inhibition, and the expression of DNA-dependent protein kinase (DNA-PK), which interacts constitutively with c-Abl, was significantly decreased in drug sensitive CEM and MCF-7 cells and poorly metastatic PC3 and KMl2 cells as compared with that of multidrug resistant CEM/MDR and MCF-7/MDR cells and highly metastatic PC3-MM2 and KM/L4a cells, respectively. These results suggest differential modulation of DNA-PK by ST1571 treatment in drug resistance and metastatic degree dependent manner. We showed that CPT as well as ST1571 significantly inhibits the expression of DNA-PK. The combined treatment with ST15fl and CPT revealed synergistic effect, and the effect was accompanied by inhibition of cell proliferation due to significant reduced expression of DNA-PK components, which resulted in CPT sensitizes human cancer cells resistant to ST1571. Therefore, the results of our study suggested that the suppression of DNA-PK using combination of ST1571 and CPT could be a novel molecular target for against drugresistant and metastatic cancer cells.