• Title/Summary/Keyword: Intrinsic pathway

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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.

Ras GTPases and Ras GTPase Activating Proteins (RasGAPs) in Human Disease (Ras GTPase 및 Ras GTPase activating protein과 사람의 질병)

  • Chang, Jong-Soo
    • Journal of Life Science
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    • v.28 no.9
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    • pp.1100-1117
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    • 2018
  • The Ras superfamily of small G-proteins acts as a molecular switch on the intracellular signaling pathway. Upon ligand stimulation, inactive GTPases (Ras-GDP) are activated (Ras-GTP) using guanine nucleotide exchange factor (GEF) and transmit signals to their downstream effectors. Following signal transmission, active Ras-GTP become inactive Ras-GDP and cease signaling. However, the intrinsic GTPase activity of Ras proteins is weak, requiring Ras GTPase-activating protein (RasGAP) to efficiently convert RAS-GTP to Ras-GDP. Since deregulation of the Ras pathway is found in nearly 30% of all human cancers, it might be useful to clarify the structural and physiological roles of Ras GTPases. Recently, RasGAP has emerged as a new class of tumor-suppressor protein and a potential therapeutic target for cancer. Therefore, it is important to clarify the physiological roles of the individual GAPs in human diseases. The first RasGAP discovered was RASA1, also known as p120 RasGAP. RASA1 is widely expressed, independent of cell type and tissue distribution. Subsequently, neurofibromatosis type 1 (NF1) was discovered. The remaining GAPs are affiliated with the GAP1 and synaptic GAP (SynGAP) families. There are more than 170 Ras GTPases and 14 Ras GAP members in the human genome. This review focused on the current understanding of Ras GTPase and RasGAP in human diseases, including cancers.

Induction of Apoptosis by Ethanol Extracts of Fermented Agabeans in AGS Human Gastric Carcinoma Cells (AGS 인체위암세포에서 발효된 아가콩 추출물에 의한 apoptosis 유도)

  • Kim, Sung-Ryeal;Lee, Hye-Hyeon;Kim, Min-Jeong;Seo, Min-Jeong;Hong, Su-Hyun;Choi, Yung-Hyun;Kang, Byoung-Won;Park, Jeong-Uck;Joo, Woo-Hong;Rhu, Eun-Ju;Jeong, Yong-Kee
    • Journal of Life Science
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    • v.20 no.12
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    • pp.1872-1881
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    • 2010
  • Extracts of soybeans fermented by Bacillus subtilis have a wide variety of functions, such as enhancing the body's immune function, fibrinolysis activity, anti-inflammation, anti-cancer, estrogen function and anti-infection effects. Recently, it was reported that the extracts of fermented beans exhibit strong anti-inflammatory and anti-cancer properties by suppressing the transcription of pro-inflammatory cytokine genes and induction of apoptosis, respectively. However, the mechanisms of their cytotoxicity in human gastric cancer cells are poorly understood. In the present study, we investigated the effects of ethyl alcohol extracts from fermented soybean (FS) and yellow agabean (FYA) on cell growth and apoptosis in AGS human gastric cancer cells. A treatment of FS and FYA inhibited the growth of AGS cells in a concentration-dependent manner by inducing apoptosis. FS- and FYA-induced apoptosis were associated with down-regulation of XIAP and cIAP-2, and up-regulation of pro-apoptotic Bax expression. Moreover, a treatment of FS and FYA not only triggered an increase in the levels of death receptor (DR)4, DR5, Fas and FasL, but also induced the activation of casepase-3, -8 and -9. These findings illustrate that FS and FYA may have a therapeutic potential in human gastric AGS cells and as a functional food.

Inhibition of cell growth and induction of apoptosis by acacetin in FaDu human pharyngeal carcinoma cells

  • Kang, Kyeong-Rok;Kim, Jae-Sung;Kim, Tae-Hyeon;Seo, Jeong-Yeon;Park, Jong-Hyun;Lim, Jin Woong;Yu, Sun-Kyoung;Kim, Heung-Joong;Shin, Sang Hun;Park, Bo-Ram;Kim, Chun Sung;Kim, Do Kyung
    • International Journal of Oral Biology
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    • v.45 no.3
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    • pp.107-114
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    • 2020
  • Acacetin, which is present in damiana (Turnera diffusa) and black locust (Robinia pseudoacacia), has several pharmacologic activities such as antioxidant, anti-inflammatory, and anti-proliferative effects on cancer cells. However, the effect of acacetin on head and neck cancers has not been clearly established. This study aimed to examine the effects of acacetin on cell growth and apoptosis induction in FaDu human pharyngeal carcinoma cells. These were investigated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, Live/Dead cell assay, 4',6-diamidino-2-phenylindole dihydrochloride staining, caspase-3 and caspase-7 activation assay, and immunoblotting in FaDu cells. Acacetin induced FaDu cell death in a dose-dependent manner, with an estimated IC50 value of 41.9 µM, without affecting the viability of L-929 mouse fibroblasts as normal cells. Acacetin treatment resulted in nuclear condensation in the FaDu cells. It promoted the proteolytic cleavage of procaspase-3, -7, -8, and -9 with increasing amounts of the cleaved caspase isoforms in FaDu cells. Acacetin-induced apoptosis in FaDu cells was mediated by the expression of Fas and activation of caspase-8, caspase-3, and poly (ADP-ribose) polymerase. Immunoblotting showed downregulation of the anti-apoptotic mitochondrial proteins Bcl-2 and Bcl-xL, but upregulation of the mitochondria-dependent pro-apoptotic proteins Bax and Badin FaDu cells after acacetin treatment. These findings indicate that acacetin inhibits cell proliferation and induces apoptotic cell death in FaDu human pharyngeal carcinoma cells via both the death receptor-mediated extrinsic apoptotic pathway and the mitochondria-mediated intrinsic apoptotic pathway.

Anti-cancer effects of kelp extract in mouse melanoma B16-F0 cell line through apoptosis (마우스 흑색종 세포주 B16-F0에서 다시마 추출물의 세포사멸을 통한 항암 효과)

  • Lee, Seong-Uk;Kim, Yoon Hee
    • Korean Journal of Food Science and Technology
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    • v.54 no.2
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    • pp.134-140
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    • 2022
  • Kelp belongs to the brown algae family and has been reported to exert anti-cancer effects on some cancer types, however studies have not been reported on the anti-cancer effects of kelp extracts on melanoma. In this study, the anti-cancer effects of kelp extract in B16-F0 cells were investigated, and the underlying molecular mechanisms were assessed. Kelp extract was found to inhibit the proliferation of B16-F0 cells, induce cytotoxicity, inhibit cell colony formation, and induce DNA fragmentation and apoptosis. The molecular mechanism was found to involve kelp extract increasing the expression of cytochrome-c and activated caspase-9 in the intrinsic apoptotic pathway. In addition, kelp extract upregulated the expression of Fas-associated protein with death domain and activated caspase-8 in the extrinsic apoptosis pathway. Activation of caspase-9 and caspase-8 by kelp extract induced activation of caspase-3 and cleaved poly adenosine diphosphate-ribose polymerase, consequently inducing apoptosis. These data suggest that kelp extract represents a potential therapeutic agent for melanoma.

Molecular Mechanism of Photic-Entrainment of Chicken Pineal Circadian Clock

  • Okano, Toshiyuki;Fukada, Yoshitaka
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.25-28
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    • 2002
  • The chicken pineal gland has been used for studies on the circadian clock, because it retains an intracellular phototransduction pathway regulating the phase of the intrinsic clock oscillator. Previously, we identified chicken clock genes expressed in the gland (cPer2, cPer3, cBmal1, cBmal2, cCry1, cCry2, and cClock), and showed that a cBMALl/2-cCLOCK heteromer acts as a regulator transactivating cPer2 gene through the CACGTG E-box element found in its promoter. Notably, mRNA expression of cPer2 gene is up-regulated by light as well as is driven by the circadian clock, implying that light-dependent clock resetting may involve the up-regulation of cPer2 gene. To explore the mechanism of light-dependent gene expression unidentified in animals, we first focused on pinopsin gene whose mRNA level is also up-regulated by light. A pinopsin promoter was isolated and analyzed by transcriptional assays using cultured chicken pineal cells, resulting in identification of an 18-bp light-responsive element that includes a CACGTG E-box sequence. We also investigated a role of mitogen-activated protein kinase (MAPK) in the clock resetting, especially in the E-box-dependent transcriptional regulation, because MAPK is phospholylated (activated) in a circadian manner and is rapidly dephosphorylated by light in the gland. Both pulldown analysis and kinase assay revealed that MAPK directly associates with BMAL1 to phosphorylate it at several Ser/Thr residues. Transcriptional analyses implied that the MAPK-mediated phosphorylation may negatively regulate the BMAL-CLOCK-dependent transactivation through the E-box. These results suggest that the CACGTG E-box serves not only as a clock-controlled element but also as a light-responsive element.

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Induction of P3NS1 Myeloma Cell Death and Cell Cycle Arrest by Simvastatin and/or γ-Radiation

  • Abdelrahman, Ibrahim Y;Helwa, Reham;Elkashef, Hausein;Hassan, Nagwa HA
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.16
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    • pp.7103-7110
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    • 2015
  • The present study was conducted to investigate the effect of ${\gamma}$-radiation alone or combined with a cytotoxic drug, simvastatin, on viability and cell cycling of a myeloma cell line. P3NS1 myeloma cells were treated with the selected dose of simvastatin ($0.1{\mu}M/l$) 24 hours prior to ${\gamma}$-irradiation (0.25, 0.5 and 1Gy). The cell viability, induction of apoptosis, cell death, cell cycling, generation of ROS, and expression of P53, Bax, Bcl2, caspase3, PARP1 and Fas genes were estimated. The results indicated that simvastatin ($0.1{\mu}M/l$) treatment for 24 hours prior to ${\gamma}$-irradiation increased cell death to 37.5% as compared to 4.81% by radiation (0.5Gy) alone. It was found that simvastatin treatment before irradiation caused arrest of cells in G0/G1 and G2/M phases as assessed using flow cytometry. Interestingly, simvastatin treatment of P3NS1 cells increased the intracellular ROS production and decreased antioxidant enzyme activity with increased P53, Bax and Caspase3 gene expression while that of Bcl2 was decreased. Consequently, our results indicated that pre-treatment with simvastatin increased radio sensitivity of myeloma tumor cells in addition to apoptotic effects through an intrinsic mitochondrial pathway.

Inhibitory Effects of Gardeniae Fructus on Apoptosis induced by 4-HNE in PC-12 Cell (치자(梔子)의 Apoptosis유발 억제효과)

  • Han, Yong-Soo;Lee, Tae Hee;Kim, Youn-Sub
    • Herbal Formula Science
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    • v.26 no.3
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    • pp.195-205
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    • 2018
  • Objectives : The purpose of this study was to observe the effects of Gardeniae Fructus on 4-HNE-induced apoptosis in PC-12 cell. Methods : A MTT assay was conducted to observe the cytotoxicity of Gardeniae Fructus on the PC-12 cell viability and the cytoprotective effects of Gardeniae Fructus on PC-12 cell against oxidative stress caused by 4-HNE. And western blot was conducted to observe the expression of Bax, Bcl-2, Caspase-3, $TNF-{\alpha}$ proteins which are involved in intrinsic and extrinsic apoptosis pathway. Results : 25, 50, 100, 200 and $400{\mu}g/m{\ell}$ of Gardeniae Fructus water extract had no cytotoxicity on PC-12 cell. $200{\mu}g/m{\ell}$ of Gardeniae Fructus water extract had significant cytoprotective effect on PC-12 cell against oxidative stress caused by 4-HNE. The expression of Bax protein in 50, 100 and $200{\mu}g/m{\ell}$ of Gardeniae Fructus was significantly decreased in PC-12 cell. The expression of Bcl-2 protein in $200{\mu}g/m{\ell}$ of Gardeniae Fructus was significantly increased in PC-12 cell. The expression of Caspase-3 protein in 100 and $200{\mu}g/m{\ell}$ of Gardeniae Fructus was significantly decreased in PC-12 cell. The expression of $TNF-{\alpha}$ protein in $50{\mu}g/m{\ell}$ of Gardeniae Fructus was significantly decreased in PC-12 cell. Conclusions : These results suggest that Gardeniae Fructus water extract is effective to protect PC-12 cell from 4-HNE induced apoptosis.

Induction of Apoptosis and Inhibition of NO Production by Piceatannol in Human Lung Cancer A549 Cells (A549 인체 폐암세포에서 piceatannol에 의한 apoptosis 유발과 NO 생성의 억제)

  • Choi, Yung-Hyun
    • Journal of Life Science
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    • v.22 no.6
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    • pp.815-822
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    • 2012
  • Piceatannol (trans-3,4,3',5'-tetrahydroxystilbene), a natural stilbene, is an analogue of resveratrol. Although recent experimental data have revealed the health benefit potency of piceatannol, the molecular mechanisms underlying the anti-cancer activity have not yet been studied in detail. In the present study, the further possible mechanisms by which piceatannol exerts its pro-apoptotic action in cultured human lung cancer A549 cells were investigated. Exposure of A549 cells to piceatannol resulted in growth inhibition and induction of apoptosis. Apoptosis induction of A549 cells by piceatannol showed correlation with proteolytic activation of caspase-3, -8, and -9, and concomitant degradation of activated caspase-3 target proteins such as poly (ADP-ribose) polymerase, phospholipase C-${\gamma}1$, ${\beta}$-catenin, and Inhibitor caspase-activated DNase. The increase in apoptosis by piceatannol treatment was also associated with an increase of pro-apoptotic Bax expression and decrease of anti-apoptotic Bcl-2 and Bcl-xL expression, and caused down-regulation of the inhibitor of apoptosis protein family members and up-regulation of Fas and Fas legend. In addition, piceatannol treatment markedly inhibited the expression of mRNA and proteins of inducible nitric oxide (NO) synthase, and the levels of NO production were progressively down-regulated by piceatannol treatment in a dose-dependent fashion. The results indicate that piceatannol may have therapeutic potential against human gastric cancer cells.

An Anticoagulant Polysaccharide Isolated from the Alkali Extracts of Coriolus versicolor (구름버섯 알칼리 추출물에서 분리한 항응고성 다당류)

  • Lee, Hyun-Sun;Kweon, Mee-Hyang;Lim, Wang-Jin;Sung, Ha-Chin;Yang, Han-Chul
    • Korean Journal of Food Science and Technology
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    • v.29 no.2
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    • pp.369-375
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    • 1997
  • We have isolated an anticoagulant polysaccharide from the alkali extracts of Coriolus versicolor. The anticoagulant polysaccharide was purified through a gradual ethanol precipitation and three concecutive chromatography of DEAE-Toyopearl 650C, Sephadex G-100, and Sepharose CL-6B by measuring activated partial thromboplastin time (aPTT). The anticoagulant polysaccharide showed the homogenecity on HPLC using a gel permeation column and had about $7.2{\times}10^{5}$ molecular weight. The polysaccharide consisted of fucose, glucose, and galactose in a molar ratio of 1.0:0.2:0.2:0.1, and also compromised 19.32% of sulfate at its constituent sugars. The polysaccharide showed the two typical bands of C-O-S $(823\;cm^{-1})$ and S=O $(1257\;cm^{-1})$ in the IR spectroscopy. The sulfated polysaccharide (CV-40-Va-1) inhibited the blood coagulation via the intrinsic pathway like heparin whose activity produced a concentration dependent effect in aPTT and thrombin time (TT).

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