• Title/Summary/Keyword: p53 pathway

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Anti-Inflammatory and Antioxidative Effects of Acaiberry in Formalin-Induced Orofacial Pain in Rats (흰쥐의 악안면 통증에서 아사이베리의 항염증 및 항산화 효과)

  • Kim, Yun-Kyung;Hyun, Kyung-Yae;Lee, Min-Kyung
    • Journal of dental hygiene science
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    • v.14 no.2
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    • pp.240-247
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    • 2014
  • Acaiberry (Euterpe oleracea Mart.) is widely diffused in amazon and is known that has high antioxidant capacity and potential anti-inflammatory activities. The aim of this study was to evaluate analgesic effects of acaiberry in formalin-induced orofacial pain through p38 mitogen-activated protein kinases (p38 MAPK) and nicotinamide adenine dinucleotide phosphate 4 (NOX4) pathway. Rats were divided into 5 groups (n=6); formalin (5%, $50{\mu}L$), formalin after saline (vehicle) or acaiberry (16, 80, 160 mg/kg, intraperitoneally). The nociceptive response was investigated all of groups, p38 MAPK or NOX4 were analysed at dose of 80 mg/kg of acaiberry in rat's medulla oblongata and adrenal gland. Results indicated that acai berry produced analgesic effect in a dose-dependent manner and significantly reduced formalin-induced nociceptive response at 15~40 min. Acaiberry (80 mg/kg) decreased the increased p38 MAPK activation and NOX4 expression in medulla oblongata and adrenal gland. Based on these results, acaiberry is believed to be useful for modulation of orofacial pain and its treatments because of its anti-inflammatory and antioxidative effects.

Regulation of Bcl-2 Family and Cyclooxygenases by Furanoterpenoids Isolated from a Marine Sponge Swcotragus nt. in Human Lung Cancer A549 Cells. (인체폐암세포의 Bcl-2 family 및 cyclooxygenases의 발현에 미치는 해면동물 Sarcotragus sp. 유래 furanoterpenoids의 영향)

  • 최영현;최혜정;김남득;정지형
    • Journal of Life Science
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    • v.14 no.3
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    • pp.445-452
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    • 2004
  • We investigated the cytotoxic effects of seven furanoterpenoids 〔sarcotin A, epi-sarcotin A, ircinin-1, epi-sarcotrine B, sarcotin I, (8E, l3Z, 20Z)-strobilinin/(7E,l3Z, 20Z)-felixinin and (7E,12E,18R,20Z)-variabilin〕 isolated from the sponge Sarcotragus sp. (the order Dictyoceratida) on the growth of A549 human lung carcinoma cells. MTT data revealed that sarcotin A and (7E,12E,18R,20Z)-variabilin exhibited higher potencies on the anti-proliferative activities than the other compounds in A549 cells. The growth inhibition by treatment with compounds (especially epi-sarcotin A, ircinin-1 and epi-sarcotrine B) were associated with the induction of apoptotic cell death through the concentration-dependent increase of Bax/Bcl-2 ratio in a p53-dependent or independent pathway Additionally, epi-sarcotin A and ircinin-1 strongly inhibited the levels of cyclooxygenase (COX)-2 expression without alteration of COX-1. Taken together, the results suggest that the furanoterpenoids from the marine sponge have strong potentials as candidates for anti-cancer drugs.

Dexamethasone Interferes with Autophagy and Affects Cell Survival in Irradiated Malignant Glioma Cells

  • Komakech, Alfred;Im, Ji-Hye;Gwak, Ho-Shin;Lee, Kyue-Yim;Kim, Jong Heon;Yoo, Byong Chul;Cheong, Heesun;Park, Jong Bae;Kwon, Ji Woong;Shin, Sang Hoon;Yoo, Heon
    • Journal of Korean Neurosurgical Society
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    • v.63 no.5
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    • pp.566-578
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    • 2020
  • Objective : Radiation is known to induce autophagy in malignant glioma cells whether it is cytocidal or cytoprotective. Dexamethasone is frequently used to reduce tumor-associated brain edema, especially during radiation therapy. The purpose of the study was to determine whether and how dexamethasone affects autophagy in irradiated malignant glioma cells and to identify possible intervening molecular pathways. Methods : We prepared p53 mutant U373 and LN229 glioma cell lines, which varied by phosphatase and tensin homolog (PTEN) mutational status and were used to make U373 stable transfected cells expressing GFP-LC3 protein. After performing cell survival assay after irradiation, the IC50 radiation dose was determined. Dexamethasone dose (10 μM) was determined from the literature and added to the glioma cells 24 hours before the irradiation. The effect of adding dexamethasone was evaluated by cell survival assay or clonogenic assay and cell cycle analysis. Measurement of autophagy was visualized by western blot of LC3-I/LC3-II and quantified by the GFP-LC3 punctuated pattern under fluorescence microscopy and acridine orange staining for acidic vesicle organelles by flow cytometry. Results : Dexamethasone increased cell survival in both U373 and LN229 cells after irradiation. It interfered with autophagy after irradiation differently depending on the PTEN mutational status : the autophagy decreased in U373 (PTEN-mutated) cells but increased in LN229 (PTEN wild-type) cells. Inhibition of protein kinase B (AKT) phosphorylation after irradiation by LY294002 reversed the dexamethasone-induced decrease of autophagy and cell death in U373 cells but provoked no effect on both autophagy and cell survival in LN229 cells. After ATG5 knockdown, radiation-induced autophagy decreased and the effect of dexamethasone also diminished in both cell lines. The diminished autophagy resulted in a partial reversal of dexamethasone protection from cell death after irradiation in U373 cells; however, no significant change was observed in surviving fraction LN229 cells. Conclusion : Dexamethasone increased cell survival in p53 mutated malignant glioma cells and increased autophagy in PTEN-mutant malignant glioma cell but not in PTEN-wildtype cell. The difference of autophagy response could be mediated though the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin signaling pathway.

Kaempferol Activates G2-Checkpoint of the Cell Cycle Resulting in G2-Arrest and Mitochondria-Dependent Apoptosis in Human Acute Leukemia Jurkat T Cells

  • Kim, Ki Yun;Jang, Won Young;Lee, Ji Young;Jun, Do Youn;Ko, Jee Youn;Yun, Young Ho;Kim, Young Ho
    • Journal of Microbiology and Biotechnology
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    • v.26 no.2
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    • pp.287-294
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    • 2016
  • The effect of kaempferol (3,5,7,4-tetrahydroxyflavone), a flavonoid compound that was identified in barnyard millet (Echinochloa crus-galli var. frumentacea) grains, on G2-checkpoint and apoptotic pathways was investigated in human acute leukemia Jurkat T cell clones stably transfected with an empty vector (J/Neo) or a Bcl-xL expression vector (J/Bcl-xL). Exposure of J/Neo cells to kaempeferol caused cytotoxicity and activation of the ATM/ATR-Chk1/Chk2 pathway, activating the phosphorylation of p53 (Ser-15), inhibitory phosphorylation of Cdc25C (Ser-216), and inactivation of cyclin-dependent kinase 1 (Cdk1), with resultant G2-arrest of the cell cycle. Under these conditions, apoptotic events, including upregulation of Bak and PUMA levels, Bak activation, mitochondrial membrane potential (Δψm) loss, activation of caspase-9, -8, and -3, anti-poly (ADP-ribose) polymerase (PARP) cleavage, and accumulation of apoptotic sub-G1 cells, were induced without accompanying necrosis. However, these apoptotic events, except for upregulation of Bak and PUMA levels, were completely abrogated in J/Bcl-xL cells overexpressing Bcl-xL, suggesting that the G2-arrest and the Bcl-xL-sensitive mitochondrial apoptotic events were induced, in parallel, as downstream events of the DNA-damage-mediated G2-checkpoint activation. Together these results demonstrate that kaempferol-mediated antitumor activity toward Jurkat T cells was attributable to G2-checkpoint activation, which caused not only G2-arrest of the cell cycle but also activating phosphorylation of p53 (Ser-15) and subsequent induction of mitochondria-dependent apoptotic events, including Bak and PUMA upregulation, Bak activation, Δψm loss, and caspase cascade activation.

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.

Mechanism of Resistance and Epithelial to Mesenchymal Transition of BRAF(V600E) Mutation Thyroid Anaplastic Cancer to BRAF(V600E) Inhibition Through Feedback Activation of EGFR (BRAF(V600E) 돌연변이 갑상선 역형성암에서 BRAF(V600E) 억제에 의한 EGFR 발현 증가가 표적치료에 대한 저항성발현과 상피-간질세포이행과정에 미치는 영향분석)

  • Byeon, Hyung Kwon;Na, Hwi Jung;Yang, Yeon Ju;Park, Jae Hong;Kwon, Hyeong Ju;Chang, Jae Won;Ban, Myung Jin;Kim, Won Shik;Shin, Dong Yeob;Lee, Eun Jig;Koh, Yoon Woo;Choi, Eun Chang
    • Korean Journal of Head & Neck Oncology
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    • v.30 no.2
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    • pp.53-61
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    • 2014
  • Background and Objectives : Anaplastic thyroid carcinoma(ATC) is a rare but highly aggressive thyroid malignancy that is associated with an extremely poor survival despite the best multidisciplinary care. BRAF(V600E) mutation is detected in about a quarter of ATC, but unlike its high treatment response to selective BRAF inhibitor (PLX4032) in metastatic melanoma, the treatment response of ATC is reported to be low. The purpose of this study is to investigate the innate resistance mechanism responsible for this low treatment response to BRAF inhibitor and its effect on epithelial-mesenchymal transition(EMT). Materials and Methods : Two ATP cell lines, 8505C and FRO were selected and treated with PLX4032 and its drug sensitivity and effects on cell migration and EMT were examined and compared. Further investigation on the changes in signals responsible for the different treatment response to PLX4032 was carried out and the same experiment was performed on both orthotopic and ectopic xenograft mouse models. Results : FRO cell line was more sensitive to PLX4032 treatment compared to 8505C cell line. The resistance to BRAF inhibition in 8505C was due to increased expression of EGFR. Effective inhibition of both EGFR and p-AKT was achieved after dual treatment with BRAF inhibitor(PLX4032) and EGFR inhibitor(Erlotinib). Similar results were confirmed on in vivo study. Conclusion : EGFR-mediated reactivation of the PI3K/AKT pathway and MAPK pathway contributes to the relative insensitivity of BRAF(V600E) mutant ATC cells to PLX4032. Dual inhibition of BRAF and EGFR leads to sustained treatment response including cell invasiveness.

In-silico annotation of the chemical composition of Tibetan tea and its mechanism on antioxidant and lipid-lowering in mice

  • Ning Wang ;Linman Li ;Puyu Zhang;Muhammad Aamer Mehmood ;Chaohua Lan;Tian Gan ;Zaixin Li ;Zhi Zhang ;Kewei Xu ;Shan Mo ;Gang Xia ;Tao Wu ;Hui Zhu
    • Nutrition Research and Practice
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    • v.17 no.4
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    • pp.682-697
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    • 2023
  • BACKGROUND/OBJECTIVES: Tibetan tea is a kind of dark tea, due to the inherent complexity of natural products, the chemical composition and beneficial effects of Tibetan tea are not fully understood. The objective of this study was to unravel the composition of Tibetan tea using knowledge-guided multilayer network (KGMN) techniques and explore its potential antioxidant and hypolipidemic mechanisms in mice. MATERIALS/METHODS: The C57BL/6J mice were continuously gavaged with Tibetan tea extract (T group), green tea extract (G group) and ddH2O (H group) for 15 days. The activity of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) in mice was detected. Transcriptome sequencing technology was used to investigate the molecular mechanisms underlying the antioxidant and lipid-lowering effects of Tibetan tea in mice. Furthermore, the expression levels of liver antioxidant and lipid metabolism related genes in various groups were detected by the real-time quantitative polymerase chain reaction (qPCR) method. RESULTS: The results showed that a total of 42 flavonoids are provisionally annotated in Tibetan tea using KGMN strategies. Tibetan tea significantly reduced body weight gain and increased T-AOC and SOD activities in mice compared with the H group. Based on the results of transcriptome and qPCR, it was confirmed that Tibetan tea could play a key role in antioxidant and lipid lowering by regulating oxidative stress and lipid metabolism related pathways such as insulin resistance, P53 signaling pathway, insulin signaling pathway, fatty acid elongation and fatty acid metabolism. CONCLUSIONS: This study was the first to use computational tools to deeply explore the composition of Tibetan tea and revealed its potential antioxidant and hypolipidemic mechanisms, and it provides new insights into the composition and bioactivity of Tibetan tea.

Candida magnoliae에 의한 erythritol 생산을 위한 유가식 공정의 개발

  • Park, Chang-Yeol;Seo, Jin-Ho;Yu, Yeon-U
    • 한국생물공학회:학술대회논문집
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    • 2000.04a
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    • pp.53-56
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    • 2000
  • Two-stage fed-batch culture was peformed to improve the volumetric productivity of erythritol. In the growth phase dissolved oxygen was maintained to 20% and the feed medium was automatically supplied to the fermenter by pH-stat mode. The cell yield was 0.76 g-cell/g-glucose. In two-stage fed-batch culture, 41% of total erythritol conversion yield with 187 g/L of erythritol concentration and 2.79 g/L-h of maximum erythritol Productivity were obtained when 400 g/L of glucose was directly added in the form of non-sterile powder at production phase. The erythritol productivity increased in parallel with cell mass. The metabolic shift in the biosynthetic pathway of erythritol was caused by dissolved oxygen concentration. The production of gluconic acid was observed when the dissolved oxygen in the medium was maintained over 40% during the production phase, whereas the dissolved oxygen concentration lower than 40% caused the production of citric acid. But the butyric acid was produced independently with dissolved oxygen concentration in the medium. The production of organic acids such as gluconic acid, citric acid, and butyric acid was decreased by addition of mineral salts.

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Biosynthesis of Lactate-containing Polyhydroxyalkanoates in Recombinant Escherichia coli from Sucrose (재조합 대장균에서 수크로즈로부터의 젖산을 모노머로 함유한 폴리하이드록시알칸산 생산 연구)

  • Oh, Young Hoon;Kang, Kyoung-Hee;Shin, Jihoon;Song, Bong Keun;Lee, Seung Hwan;Lee, Sang Yup;Park, Si Jae
    • KSBB Journal
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    • v.29 no.6
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    • pp.443-447
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    • 2014
  • Biosynthesis of lactate-containing polyhydroxyalkanoates (PHAs) was examined in recombinant Escherichia coli W strain from sucrose. The Pseudomonas sp. MBEL 6-19 phaC1437 gene and the Clostridium propionicum pct540 gene, which encode engineered Pseudomonas sp. MBEL 6-19 PHA synthase 1 ($PhaC1_{Ps6-19}$) and engineered C. propionicum propionyl-CoA transferase ($Pct_{Cp}$), respectively, were expressed in E. coli W to construct key metabolic pathway to produce poly(3-hydroxybutyrate-co-lactate) [P(3HB-co-LA)]. The recombinant E. coli W expressing the phaC1437 gene and the pct540 gene could synthesize P(3HB-co-13mol%LA) up to the polymer content of 31.3 wt% when it was cultured in chemically defined MR medium containing 20 g/L of sucrose and 2 g/L of sodium 3-hydroxybutyrate. When Ralstonia eutropha phaAB genes were additionally expressed to provide 3-hydroxybutyrate-CoA (3HB-CoA) from sucrose, P(3HB-co-16mol%LA) could be synthesized from sucrose as a sole carbon source without supplement of sodium 3-hydroxybutyrate in culture medium, but the PHA content was decreased to 12.2 wt%. The molecular weight of P(3HB-co-16 mol%LA) synthesized in E. coli W using sucrose as carbon source were $1.53{\times}10^4$ ($M_n$) and $2.78{\times}10^4$ ($M_w$), respectively, which are not different from those that have previously been reported by other recombinant E. coli strains. Engineered E. coli strains developed in this study should be useful for the production of lactate-containing PHAs from sucrose, one of the most abundant and least expensive carbon sources.

In vitro Study of Nucleostemin as a Potential Therapeutic Target in Human Breast Carcinoma SKBR-3 Cells

  • Guo, Yu;Liao, Ya-Ping;Zhang, Ding;Xu, Li-Sha;Li, Na;Guan, Wei-Jun;Liu, Chang-Qing
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.2291-2295
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    • 2014
  • Although nucleolar protein nucleostemin (NS) is essential for cell proliferation and early embryogenesis and expression has been observed in some types of human cancer and stem cells, the molecular mechanisms involved in mediation of cell proliferation and cell cycling remains largely elusive. The aim of the present study was to evaluate NS as a potential target for gene therapy of human breast carcinoma by investigating NS gene expression and its effects on SKBR-3 cell proliferation and apoptosis. NS mRNA and protein were both found to be highly expressed in all detected cancer cell lines. The apoptotic rate of the pcDNA3.1-NS-Silencer group ($12.1-15.4{\pm}3.8%$) was significantly higher than those of pcDNA3.1-NS ($7.2-12.0{\pm}1.7%$) and non-transfection groups ($4.1-6.5{\pm}1.8%$, P<0.01). MTT assays showed the knockdown of NS expression reduced the proliferation rate of SKBR-3 cells significantly. Matrigel invasion and wound healing assays indicated that the number of invading cells was significantly decreased in the pcDNA3.1-NS-siRNA group (P<0.01), but there were no significant difference between non-transfected and over-expression groups (P>0.05). Moreover, RNAi-mediated NS down-regulation induced SKBR-3 cell G1 phase arrest, inhibited cell proliferation, and promoted p53 pathway-mediated cell apoptosis in SKBR-3 cells. NS might thus be an important regulator in the G2/M check point of cell cycle, blocking SKBR-3 cell progression through the G1/S phase. On the whole, these results suggest NS might be a tumor suppressor and important therapeutic target in human cancers.