• 제목/요약/키워드: synergistic inhibition.

검색결과 241건 처리시간 0.031초

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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    • 제22권3호
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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
    • 한국발생생물학회지:발생과생식
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    • 제23권2호
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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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    • 제27권10호
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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
    • 대한약침학회지
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    • 제16권2호
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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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    • 제45권11호
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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.

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

  • 곽화숙;김보관;김진석
    • Weed & Turfgrass Science
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    • 제5권3호
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    • pp.136-143
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    • 2016
  • 본 연구에서는 캐슈넛 오일의 살조활성 특징을 파악하고, 유해조류를 보다 효과적으로 제어할 수 있는 혼합처리제를 개발하기 위하여 실시하였다. 공시된 시험 추출물중 anacardic acid 함량이 상대적으로 높은 Ana-A가 남조류 M. aeruginosa에 대한 살조활성이 가장 높았다. Ana-A는 전체적으로 녹조류보다는 남조류에 대해 더 높은 살조활성을 가지면서 폭넓은 살조활성스펙트럼을 보였다. Ana-A에 대한 남조류 종간 반응에 있어서는 Oscillatoria tenuis ($IC_{50}=0.19{\mu}g\;mL^{-1}$)가 가장 민감하였고, 녹조류 중에서는 Chlorella vulgaris가 상대적으로 가장 민감한 반응을 나타내었다($IC_{50}=4.54{\mu}g\;mL^{-1}$). Ana-A와의 혼합처리를 통해 효능이 상승되는 화합물을 탐색한 결과, MSB와 menadione은 매우 강한 상승작용을, citric acid는 약간의 상승작용을, chrysophanol, copper sulfate, quinoclamine 등은 상가적 작용의 활성을 나타내었다. 종합적으로 볼 때, anacardic acid 고함유 캐슈넛 오일은 처리량의 최적화와 상승작용을 가지는 MSB 또는 menadione과 같은 화합물과의 혼합처리를 통해 M. aeruginosa 및 O. tenuis가 발생하는 현장의 선택적 제어를 위해 환경 친화적인 살조제로서 유용하게 활용될 수 있을 것 같았다.

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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    • 제53권10호
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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.

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

  • 박정애;진경숙;이지영;권현주;김병우
    • 한국미생물·생명공학회지
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    • 제41권3호
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    • pp.341-349
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    • 2013
  • 본 연구에서는 통초(Tetrapanax papyriferus)와 희렴(Siegesbeckia pubescens)의 항산화 및 항비만 활성을 DPPH radical 소거능과 세포실험계를 이용하여 분석하였다. 통초와 희렴의 DPPH radical 소거능의 50% 저해능($IC_{50}$)은 각각 65.23과 47.79 ${\mu}g/ml$로 나타났다. 또한 두 시료 모두 농도 의존적으로 lipase 효소 활성을 유의적으로 억제시켰으며, 3T3-L1 preadipocyte를 이용하여 지방세포 분화 및 지방생성에 미치는 영향을 분석한 결과 통초와 희렴 모두 지방 세포 분화, 지방 축적, TG 함량 등을 독성 없이 농도의존적으로 억제함을 보였다. 이러한 통초와 희렴의 지방세포분화억제능은 핵심 작용 인자인 $C/EBP{\alpha}$, $C/EBP{\beta}$, 그리고 $PPAR{\gamma}$의 유전자 및 단백질 발현조절에서 기인함을 확인하였다. 또한 통초와 희렴 간의 항비만 시너지 효과를 분석한 결과 각 시료의 단독 처리시보다 병용 처리시 더 높은 지방세포분화억제능을 보여 두 시료간에 시너지 효과를 보유함을 확인하였다. 이러한 결과는 통초 및 희렴의 항비만 활성 및 그 작용 기전을 밝힌 것이며 추후 계속적인 연구를 통해 활성 물질의 규명이 필요할 것으로 판단된다.

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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    • 제76권3호
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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.

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

  • 김미주;이상민;배재호;정병선;강치덕;김선희
    • 생명과학회지
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    • 제17권6호통권86호
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    • pp.748-755
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    • 2007
  • 본 연구에서는 전이성 암세포와 항암제 다제내성 세포에 있어서 항암제 내성에 영향을 미치는 것으로 알려진 DNA-dependent protein kinase (DNA-PK) 가 Abl protein-tyrosine kinases저해제인 STl571 내성에도 연관되어 있는지에 대하여 조사하였다. 또한 STl571 과 topoisomerase I 저해제인 camptothecin (CPT) 의 단독 및 병용처리에 의한 항암 활성을 전이성 암세포와 항암제 다제내성 세포를 대상으로 조사하였다. 세포의 전이도와 내성정도에 따라 STl571 의 감수성이 다르게 나타났다. 이와 함께 ST1571의 처리후 농도에 따라 전이도가 낮은 KMl2, PC3 세포와 항암제 감수성인 CEM, MCF-7 세포에서는 DNA-PK 의 발현이 감소하는 반면, 전이도가 높은 KML4a, PC-MM2 세포와 다제내성 CEM/MDR 및 MCR/MDR 세포에서는 그 발현이 증가되어 있음을 알 수 있었다. 이는 DNA-PK 의 발현이 STl571 의 내성에 관여한다는 것을 시사한다. 이와 같은 결과에 근거하여 DNA-PK 의 발현을 감소시키는 CPT를 STl571 내성을 나타내는 암세포에 대하여 STl571 과 병용처리 하였다. 그 결과 DNA-PK의 발현이 감소되고 세포증식이 억제됨으로써 ST1571 의 감수성이 CPT에 의해 증가하는 것을 알 수 있었다. 따라서 본 연구에서는 DNA-PK가 STl571 의 내성을 극복하는데 있어서 새로운 표적이 될 수 있으며, STl571 의 치료내성 극복에 CPT 와의 병용처리가 유효함을 알 수 있었다.