• Title/Summary/Keyword: apoptotic cells

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Silibinin Induces Apoptotic Cell Death Via ROS-dependent Mitochondrial Pathway in Human Glioma Cells

  • Shin, Won-Yong;Jeong, Ji-Cheon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.4
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    • pp.888-894
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    • 2009
  • It has been reported that silibinin, a natural polyphenolic flavonoid, induces cell death in various cancer cell types. However, the underlying mechanisms by which silibinin induces apoptosis in human glioma cells are poorly understood. The present study was therefore undertaken to examine the effect of silibinin on glioma cell apoptosis and to determine its underlying mechanism in human glioma cells. Apoptosis was estimated by FACS analysis. Reactive oxygen species (ROS) generation and mitochondrial membrane potential (${\Psi}m$) were measured using fluorescence dyes DCFH-DA and $DiOC_6$(3), respectively. Cytochrome c release from mitochondria and caspase-3 activation were estimated by Western blot analysis using specific antibodies. Exposure of cells to 30 mM silibinin induced apoptosis starting at 6 h, with increasing effects after 12-48h in a time-dependent manner. Silibinin caused ROS generation and disruption of ym, which were associated with the silibinin-induced apoptosis. The silibinin-induced ROS generation and disruption in ym were prevented by inhibitors of mitochondrial electron transport chain. The hydrogen peroxide scavenger catalase blocked ROS generation and apoptosis induced by silibinin. Silibinin induced cytochrome c release into cytosolic fraction and its effect was prevented by catalase and cyclosporine A. Silibinin treatment caused caspase-3 activation, which was inhibited by DVED-CHO and cyclosporine A. Pretreatment of caspase inhibitors also protected against the silibinin-induced apoptosis. These findings indicate that ROS generation plays a critical role in the initiation of the silibinin-induced apoptotic cascade by mediation of the mitochondrial apoptotic pathway including the disruption of ${\Psi}m$, cytochrome c release, and caspase-3 activation.

The Clinical Implications of Death Domain-Associated Protein (DAXX) Expression

  • Ko, Taek Yong;Kim, Jong In;Park, Eok Sung;Mun, Jeong Min;Park, Sung Dal
    • Journal of Chest Surgery
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    • v.51 no.3
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    • pp.187-194
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    • 2018
  • Background: Death domain-associated protein (DAXX), originally identified as a pro-apoptotic protein, is now understood to be either a pro-apoptotic or an anti-apoptotic factor with a chromatin remodeler, depending on the cell type and context. This study evaluated DAXX expression and its clinical implications in squamous cell carcinoma of the esophagus. Methods: Paraffin-embedded tissues from 60 cases of esophageal squamous carcinoma were analyzed immunohistochemically. An immune reaction with more than 10% of tumor cells was interpreted as positive. Positive reactions were sorted into 2 groups: reactions in 11%-50% of tumor cells and reactions in more than 51% of tumor cells, and the correlations between expression and survival and clinical prognosticators were analyzed. Results: Forty-three of the 60 cases (71.7%) showed strong nuclear DAXX expression, among which 19 cases showed a positive reaction (31.7%) in 11%-50% of tumor cells, and 24 cases (40.0%) showed a positive reaction in more than 51% of tumor cells. A negative reaction was found in 17 cases (28.3%). These patterns of immunostaining were significantly associated with the N stage (p=0.005) and American Joint Committee on Cancer stage (p=0.001), but overall survival showed no significant difference. There were no correlations of DAXX expression with age, gender, or T stage. However, in stage IIB (p=0.046) and stage IV (p=0.014) disease, DAXX expression was significantly correlated with survival. Conclusion: This investigation found upregulation of DAXX in esophageal cancer, with a 71.7% expression rate. DAXX immunostaining could be used in clinical practice to predict aggressive tumors with lymph node metastasis in advanced-stage disease, especially in stages IIB and IV.

Extract of Saccharina japonica Induces Apoptosis companied by Cell Cycle Arrest and Endoplasmic Reticulum Stress in SK-Hep1 Human Hepatocellular Carcinoma Cells

  • Jung, Hyun Il;Jo, Mi Jeong;Kim, Hyung-Rak;Choi, Yung Hyun;Kim, Gun-Do
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.7
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    • pp.2993-2999
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    • 2014
  • Saccharina japonica is a family member of Phaeophyceae (brown macro-alga) and extensively cultivated in China, Japan and Korea. Here, the potential anti-cancer effect of n-hexane fraction of S. japonica was evaluated in SK-Hep1 human hepatocellular carcinoma cells. The N-hexane fraction reduced cell viability and increased the numbers of apoptotic cells in a both dose- and time-dependent manner. Apoptosis was activated by both caspase-dependent and independent pathways. The caspase-dependent cell death pathway is mediated by cell surface death receptors and activated caspase-8 amplified the apoptotic signal either through direct activation of downstream caspase-3 or pro-apoptotic proteins (Bad, Bax and Bak) subsequently leading to the release of cytochrome c. On the other hand, caspase-independent apoptosis appeared mediated by disruption of mitochondrial membrane potential and translocation of AIF to the nucleus where they induced chromatin condensation and/or large-scale DNA fragmentation. In addition, the n-hexane fraction induced endoplasmic reticulum (ER)-stress and cell cycle arrest. The results suggested that potential anti-cancer effects of n-hexane extract from S. japonica on SK-Hep1 cells.

Blocking Bcl-2 Leads to Autophagy Activation and Cell Death of the HEPG2 Liver Cancer Cell Line

  • Du, Peng;Cao, Hua;Wu, Hao-Rong;Zhu, Bao-Song;Wang, Hao-Wei;Gu, Chun-Wei;Xing, Chun-Gen;Chen, Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5849-5854
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    • 2013
  • Background: Apoptosis may be induced after Bcl-2 expression is inhibited in proliferative cancer cells. This study focused on the effect of autophagy activation by ABT737 on anti-tumor effects of epirubicin. Methods: Cytotoxic effects of ABT737 on the HepG2 liver cancer cell line were assessed by MTT assay and cell apoptosis through flow cytometry. Mitochondrial membrane potential was measured by fluorescence microscopy. Monodansylcadaverin (MDC) staining was used to detect activation of autophagy. Expression of p53, p62, LC3, and Beclin1, apoptotic or autophagy related proteins, was detected by Western blotting. Results: ABT737 and epirubicin induced growth inhibition in HepG2 cells in a dose- and time-dependent manner. Both ABT737 and epirubicin alone could induce cell apoptosis with a reduction in mitochondrial membrane potential as well as increased apoptotic protein expression. Further increase of apoptosis was detected when HepG2 cells were co-treated with ABT373 and epirubicin. Furthermore, our results demonstrated that ABT373 or epirubicin ccould activate cell autophagy with elevated autophagosome formation, increased expression of autophagy related proteins and LC3 fluorescent puncta. Conclusions: ABT737 influences cancer cells through both apoptotic and autophagic mechanisms, and ABT737 may enhance the effects of epirubicin on HepG2 cells by activating autophagy and inducing apoptosis.

Apoptosis-Inducing Activity of HPLC Fraction from Voacanga globosa (Blanco) Merr. on the Human Colon Carcinoma Cell Line, HCT116

  • Acebedo, Alvin Resultay;Amor, Evangeline Cancio;Jacinto, Sonia Donaldo
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.2
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    • pp.617-622
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    • 2014
  • Voacanga globosa (Blanco), a plant endemic to the Philippines, is traditionally used especially by indigenous people of Bataan in the treatment of ulcers, wounds and tumorous growths. This study aimed to provide scientific evidence to therapeutic properties by determining cytotoxic and pro-apoptotic activity of HPLC fractions from leaves on HCT116 human colon carcinoma and A549 human lung carcinoma cell lines. Ethanolic extraction was performed on V globosa leaves followed by hexane and ethyl acetate partitioning. Silica gel column chromatography and high performance liquid chromatography (HPLC) produced MP1, MP2 and MP3 fractions. Cytotoxic activity of the fractions was determined through MTT assay against the cancer cell lines HCT116 and A549 and the non-cancer AA8 Chinese hamster ovarian cell line. Pro-apoptotic activities of the most active fractions were further assessed through DAPI staining, TUNEL assay and JC-1 mitochondrial membrane potential assay with HCT116 cells. While the MPI fraction exerted no significant activity against all cell lines tested, MP2 and MP3 fractions demonstrated high toxicity against HCT116 and A549 cells. The MP3 fraction induced formation of apoptotic bodies, condensed DNA and other morphological changes consistent with apoptosis of HCT116 cells and TUNEL assay showed significant increase in DNA fragmentation over time. In these cells, the MP3 fraction also induced mitochondrial membrane destabilization, which is generally associated with the beginning of apoptosis. Phytochemical analysis demonstrated the presence only of saponins and terpenoids in the MP3 fraction. The results indicate that the MP3 fraction exerts cytotoxic activity on HCT116 cells via induction of apoptosis triggered by loss of mitochondrial membrane potential crucial for cell survival.

STUDIES ON ANTICANCER EFFECT OF MOMORDIN ON ORAL CARCINOMA (KB) CELLS (천연약제 Momordin의 구강암(KB) 세포주에 대한 항암작용기전에 관한 연구)

  • Seo, Kyeong-Seong;Kim, Yeo-Gab
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.27 no.3
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    • pp.209-213
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    • 2001
  • Treatment of oral cancers with chemotherapeutic agents are evaluated as an effective method for remission to reduce cancer proliferation nowadays. But, minimization of side-effects such as bone marrow suppression, gastrointestinal toxicity and renal damage is another problem to be solved. Thus, a possible approach to develop a clinically applicable chemotherapeutic agents is to screen anticancer activity among traditional medicinal plants which have been used for thousands of years with very low side-effects in orient. In this study we focused on anti-oral cancer activities of momordin, which was medicinal plant extracts that was revealed anticancer activities, on KB cell(oral cancer cell). The results were as follow : 1. Momordin showed the excellent anti-oral cancer activity against KB cells. Obtained IC50 value of Momordin was $10.4{\mu}g/ml$. 2. When KB cells were treated with Momordin, dose and time dependent DNA fragmentation of KB cells were observed. DNA fragmentation was initiated on three days at the concentration of $20{\mu}g/ml$ Momordin. 3. Flow cytometry showed dose-dependent apoptotic cell increase of KB cells on Momordin. 18.55% apoptotic cell were observed up to 72 hours at the concentration of $20{\mu}g/ml$ of Momordin. 4. Momordin induced nonspecific apoptosis without specific cell cycle arrest. 5. Through MTT assay, DNA fragmentation assay and flow cytometric analysis. anticancer effect of Momordin against KB cell was induce of apoptotic cell death.

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Apoptotic Effects and Mechanism Study of Scopoletin in HepG2 Cells (Scopoletin의 간암세포에 대한 고사 유도 효과 및 기전 연구)

  • Kwon Kang-Beom;Kim Eun-Kyung;Park Sung-Joo;Song Ho-Joon;Lee Young-Rae;Park Byung-Hyun;Park Jin-Woo;Ryu Do-Gon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.6
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    • pp.1594-1598
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    • 2005
  • Scopoletin (6-methoxy-7-hydrorycournarin) is a phenolic coumarin and a member of the phytoalexins. In this study we investigated whether scopoletin causes apoptosis in human hepatoma HepG2 cells and, if so, by what mechanisms. We report that scopoletin induced apoptosis as confirmed by a chromatin condensation. The signal cascade acivated by scopoletin included the activation of caspase-3 as evidenced by increased pretense activity. Activation of caspase-3 resulted in the cleavage of 116 kDa poly(ADP-ribose) polymerase (PARP) to 85 kDa cleavage product in a dose-dependent fashion. Also, scopoletin-induced apoptotic mechanism of HepG2 cells involved the generation of hydrogen peroxide. Taken together, these results suggest that scopgletin induces hydrogen peroxide generation, which, in turn, causes activation of caspase-3, degradation of PARP, and eventually leads to apoptotic cell death in HepG2 cells.

Apoptotic effect of Pseudomonas aeruginosa exotoxin A in human tongue squamous cell carcinoma(SCC) 25 cells (Pseudomonas aeruginosa exotoxin A(PEA)가 사람혀 편평암종세포에서 나타나는 세포자멸사 작용)

  • Choi, Byul Bo-Ra;Kim, Gyoo-Cheon
    • Journal of Korean society of Dental Hygiene
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    • v.14 no.4
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    • pp.601-608
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    • 2014
  • Objectives : The purpose of the study is to examine the apoptotic effects of Pseudomonas aeruginosa exotoxin A(PEA) in squamous cell carcinoma(SCC) 25 cells. Methods : Cell growth reduction and apoptosis induced by PEA were confirmed by WST-1 assay, Hoechst 33258 staining, flow cytometry analysis, and Western blot assay. Results : The PEA treatment decreased the cell viability in a dose and time dependent manner: control; $100{\pm}0^e$(p<0.01), 0.1875 nM; $87{\pm}4.36^d$(p<0.01), 0.375 nM; $82{\pm}0.58^d$(p<0.01), 0.75 nM; $72{\pm}1.67^c$(p<0.01), 1.5 nM; $51{\pm}1.53^{bc}$(p<0.01), 7.5 nM; $31{\pm}1.20^{ab}$(p<0.01), 15 nM; $26{\pm}0.67^a$(p<0.01), control; $100{\pm}0^a$(p<0.05), 24 h; $51{\pm}1.53^b$(p<0.05), 48 h; $16{\pm}0.5^c$(p<0.05), 72 h; $12{\pm}1.67^d$%(p<0.05). The PEA was observed on SCC 25 cells with the half maximal inhibitory concentration(IC50) value of 1.5 nM at 24 hours. The PEA treated SCC 25 cells demonstrated several types of apoptotic indications, such as nuclear condensation, the increase of sub G1, and the cleavage of PARP-1 and DFF 45. Conclusions : PEA showed anti-cancer activity against SCC 25 cells via apoptosis. PEA may potentially contribute to human oral cancer treatment.

Enzyme Hydrolysates of Ginseng Marc Polysaccharides Promote the Phagocytic Activity of Macrophages Via Activation of TLR2 and Mer Tyrosine Kinase

  • Seo, Jeong Yeon;Choi, Ji Won;Lee, Jae Yeon;Park, Young Shik;Park, Yong Il
    • Journal of Microbiology and Biotechnology
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    • v.28 no.6
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    • pp.860-873
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    • 2018
  • Although ginseng marc is a by-product obtained during manufacturing of various commercial ginseng products and has been routinely discarded as a waste, it still contains considerable amounts of potential bioactive compounds, including saponins and polysaccharides. Previously, we reported that ginseng oligosaccharides derived from ginseng marc polysaccharides by enzymatic hydrolysis exert immunostimulatory activities in macrophages and these activated macrophages are in turn able to inhibit the growth of skin melanoma cells by inducing apoptosis. In the present study, a more detailed investigation of the immunostimulatory activity and underlying action mechanisms of an enzymatic hydrolysate (GEH) containing these oligosaccharides derived from ginseng marc polysaccharides was performed. The levels of proinflammatory cytokines and anti-inflammatory cytokines were measured in GEH-stimulated RAW264.7 macrophages using RT-PCR analysis and ELISA. The expression levels of Toll-like receptor 2 (TLR2) and TLR4, Dectin-1, and MerTK were measured by RT-PCR analysis or western blot analysis, and the phagocytic activities of GEH-challenged bone marrow-derived macrophages toward apoptotic Jurkat cells were assayed using fluorescence microscopy. GEH induced the production of both proinflammatory cytokines $TNF-{\alpha}$ and IL-6, and anti-inflammatory cytokine IL-10 in RAW 264.7 cells. The expression of the TLR2 and MerTK mRNAs was increased upon GEH treatment. Phagocytosis of apoptotic Jurkat cells was enhanced in GEH-treated macrophages. Based on the results, this enzymatic hydrolysate (GEH) containing oligosaccharides exerts immunostimulatory effects by maintaining the balance between M1 and M2 cytokines, facilitating macrophage activation and contributing to the efficient phagocytosis of apoptotic cells. Therefore, the GEH could be developed as value-added, health-beneficial food materials with immunostimulatory effects.

Apoptotic Effects of Co-Treatment with a Chios Gum Mastic and Eugenol on G361 Human Melanoma Cells

  • Jo, Jae-Beom;Oh, Sang-Hun;Kim, In-Ryoung;Kim, Gyoo-Cheon;Kwak, Hyun-Ho;Park, Bong-Soo
    • International Journal of Oral Biology
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    • v.38 no.3
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    • pp.101-110
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    • 2013
  • We investigated the synergistic apoptotic effects of co-treatments with Chios gum mastic (CGM) and eugenol on G361 human melanoma cells. An MTT assay was conducted to investigate whether this co-treatment efficiently reduces the viability of G361 cells compared with each single treatment. The induction and augmentation of apoptosis were confirmed by DNA electrophoresis, Hoechst staining, and analyses of DNA hypoploidy. Western blot analysis and immunofluorescent staining were also performed to evaluate expression and translocation of apoptosis-related proteins following CGM and eugenol co-treatment. Proteasome activity and mitochondrial membrane potential (MMP) changes were also assayed.The results indicated that the co-treatment of CGM and eugenol induces multiple pathways and processes associated with an apoptotic response in G361 cells. These include nuclear condensation, DNA fragmentation, a reduction in MMP and proteasome activity, an increase of Bax and decrease of Bcl-2, a decreased DNA content, cytochrome c release into the cytosol, the translocation of AIF and DFF40 (CAD) into the nucleus, and the activation of caspase-9, caspase-7, caspase-3, PARP and DFF45 (ICAD). In contrast, separate treatments of $40{\mu}g/ml$ CGM or $300{\mu}M$ eugenol for 24 hours did not induce apoptosis. Our present data thus suggest that a combination therapy of CGM and eugenol is a potential treatment strategy for human melanoma.