• Journal of Korean Ophthalmic Optics Society
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• v.12 no.2
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• pp.79-86
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• 2007

The aim of the present study was to determine mechanisms of corneal epithelial cell apoptosis in vitro following exposure to anti-FAS and anti-FAS ligand antibody and during infection with mycoplasma sp.. A cultured human corneal epithelial(HCE) cell line was treated with anti-FAS antibody or anti-FAS ligand antibody for 2 and 4 days. The original cell line was found to be contaminated by mycoplasma removal agent(MRA) was used to eliminate the bacterium from the cell line. MRA($0.5{\mu}{\ell}$ tissue culture medium) was added to the cell line and incubated for 1 week. The cell line underwent multiple passages in media not contaminating MRA and cells were grown to 50-80% confluency on coverslips and stained using the Hoechst stain provided in the kit to ensure mycoplasma removal. Apoptosis experiments were performed before and after mycoplasma removal. The apoptotic index of anti-FAS and anti-FAS ligand antibody on mycoplasma contaminated cell line was studied using Hoechst 33342 staining and Annexin V-FITC and Propidium Iodide Staining. In conclusion, anti-FAS antibody induces apoptosis in HCE cells in a time and concentration-dependent mechanism. Cell lines contaminated with mycoplasma have an incresed susceptibility to FAS induced apoptosis.

• Radiation Oncology Journal
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• v.18 no.3
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• pp.214-219
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• 2000

Purpose : To Investigate the pathways of radiation induced apoptosls and the effect of cysteamine (${\beta}$-mercaptoethyiamine), as a radioprotector, on it. Materials and Methods : HL-50 ceils were assigned to control, irradiated, and cysteamlne (1 mM, 10mM) pretreated groups. Irradiation was given In a single fraction of 10 Gy (6 MV x-ray) and cysteamine was administered 1 hour before irradiation. The activities of caspase-8 were measured in control and irradiated group to evaluate its relation to the radiation Induced apoptosis. To evaluate the role of cysteamine In radiation Induced apoptosis, the number of viable cells, the expression and activity of caspase-3, and the expression of poly (ADP-ribose) polymerase (PARP) were measured and compared after irradiating the HL-60 celis with cysteamine pretreatment or not. Results : The intraceliular caspase-8 activity, known to be related to the death receptor induced apoptosis, was not affected by irradiation(p>0.05). The number of viable cells began to decrease from 6 hours after irradiation (p>0.05), but the number of viable cells In 1 mM cysteamine pretreated group was not decreased after irradiation and was similar to those in the control group. In caspase-3 analyses, known as apoptosis executioner, its expression was not different but its activity was Increased by irradiation(p>0.05). However, this Increase of activity was suppressed by the pretreatment of 1 mM cysteamine. The cleavage of PARP, thought to be resulted from caspase-3 activation, occurred after irradiation which was attenuated by the pretreatment of 1 mM cysteamine. Conclusion : These results show that radiation induced apoptotic process is somewhat different from death receptor induced one and the pretreatment of 1 mM cysteamine has a tendency to decrease the radiation-induced apoptosis in HL-60 cells.

• Clinical and Experimental Pediatrics
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• v.46 no.7
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• pp.702-709
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• 2003

Purpose : $IFN{\gamma}$ sentitizes many tumor cells to $TNF{\alpha}$ and FASL-mediated apoptosis by enhancing the expression of TNF or FAS/CD95 receptor and modulating the activation of caspase and Bcl-2 family. It has been reported that $IFN{\gamma}$ and $TNF{\alpha}$ synergistically caused differentiation and growth inhibition of neuroblastoma cells. Even though some neuroblastoma cell express FASR/FASL on the cell surface, they could not induce apoptosis by ligation of the FAS/CD95 receptor. But the treatment of $IFN{\gamma}$ is reported to induce apoptosis in some neuroblastoma cell lines through the CD95/CD95L autocrine circuit. In this study, we examined whether $IFN{\gamma}$ could affect $TNF{\alpha}$ and agonistic FAS/CD95 antibody(CH-11)-induced apoptosis against neuroblastoma cell lines that had shown diverse drug sensitivity and resistance. Methods : CHLA-15, CHLA-90 and LA-N-2 neuroblastoma cells were cultured in IMDM and treated with recombinant $IFN{\gamma}$, $TNF{\alpha}$ and CH-11 antibody. Cell viability was measured by DIMSCAN with a fluorescent calcein-AM. Apoptosis was analyzed through flow cytometry using Annexin V-PE and 7-ADD staining and confirmed by pancaspase and caspase-8 blocking experiments. The expression of TNF RI and FAS/CD95 receptor was evaluated by flow cytometry using the corresponding antibody and PE-conjugated secondary antibody. Results : $IFN{\gamma}$ or $TNF{\alpha}$ alone had no demonstrable cytotoxic effects, whereas both cytokines in combination induced apoptosis synergistically in CHLA-15 and CHLA-90 cells. Although there was no cytotoxicity with the ligation of CH-11 alone in CHLA-90 cells, pretreatment of $IFN{\gamma}$ increased the sensitivity of CH-11-mediated apoptosis. The expression of TNFRI and FAS/CD95R were non-specifically enhanced after treatment of $IFN{\gamma}$ without relation to sensitivity to $TNF{\alpha}$ and CH-11. This finding suggest up-regulation of both receptors may contribute to sensitization of $TNF{\alpha}$ and CH-11-mediated apoptosis by $IFN{\gamma}$ in only sensitive cell lines. Conclusion : $IFN{\gamma}$ induced sensitization of $TNF{\alpha}$ and agonistic FAS/CD95 antibody-mediated apoptosis on some neuroblastoma cells through up-regulation of TNFRI and FAS/CD95 receptor.

• The korean journal of orthodontics
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• v.33 no.6 s.101
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• pp.453-463
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• 2003

Mammalian cell is critically dependent on a continuous supply of oxygen. Even brief periods of oxygen deprivation can result in profound cellular damage. The aim of this study was to examine the possible mechanism of apoptosis in response to hypoxia in MC3T3E1 osteoblasts. MC3T3El osteoblasts under hypoxic conditions ($2\%$ oxygen) resulted in apoptosis in a time-dependent manner, determined by DNA fragmentation assay and nuclear morphology, stained with fluorescent dye (Hoechst 33258) Pretreatment with Z-VAD-FMK, a pancaspase inhibitor, or Z-DEVD-CHO, a specific caspase-3 inhibitor, suppressed the DNA ladder in response to hypoxia in a concentration dependent manner. An increase in caspase-3-like protease (DEVDase) activity was observed during apoptosis, but no caspase-l activity (YVADase) was detected. To confirm what caspases were involved in apoptosis, western blot analysis was performed using an anticaspase-3 or 6 antibody. The 17-kDa protein, that corresponds to the active products of caspase-3 and the 20-kDa protein of the active protein of caspase-6 were generated in hypoxia-challenged lysates, in which the full length forms of caspase-3 and 6 were evident. With a time course similar to caspase-3 and 6 activation, hypoxic stress also caused the cleavage of Lamin A, typical of caspase-6 activity. In addition, the hypoxic stress elicited the release of cytochrome c into the cytosol during apoptosis. These findings suggested that the activation of caspases accompanied by a cytochrome c release in response to hypoxia was involved in apoptotic cell death in MC3T3E1 osteoblasts.

• Clinical and Experimental Pediatrics
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• v.52 no.6
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• pp.696-700
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• 2009

Purpose : We screened more than 350 compounds with an endoperoxide ring structure in search of an anti-leukemic drug and found that compound 127 (c-127) could induce significant cytotoxicity in HL-60 cells. In this study, we investigated the molecular mechanisms of compound 127-induced antitumor activity on HL-60 cells. Methods : HL-60 cells were cultured in Rosewell Park Memorial Institute 1640 and cell viability was measured by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide], a tetrazole assay. Apoptosis was assessed by a DNA fragmentation test. Apoptotic machineries were determined by Western blot analysis. Results : C-127 could induce a cytotoxic effect at 24 h and apoptosis at 6 h, which was demonstrated with MTT assay and DNA fragmentation test, respectively. The apoptotic effect of this drug was caused by the activation of the intracellular caspase-8,3 activation, the cleavage of pro-apoptotic Bid, and the increase of c-Jun expression accompanied with JNK (Jun N-terminal kinases) phosphorylation. On the contrary, it increased the expression of anti-apoptotic Bcl-2 levels, leading to the induction of the induction of anti-apoptotic effect. Taken together, the present study demonstrated that c-127 was a potent inducer of cytotoxicity on HL-60 cells through apoptotic mechanisms, which included the activation of caspase family, the regulation of Bcl-2 family, and the activation of JNK signaling pathway. Conclusion : Our results suggest that c-127 has a strong antitumor activity through the regulation of various apoptotic machineries on HL-60 cells. The compound may be utilized as an effective and potentially therapeutic drug in leukemia.

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.1
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• pp.1-6
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• 1999

The corneal epithelium is constantly shed and apoptosis may play an important role in this turn-over. We sought to define that serum-free medium was able to induce apoptosis of corneal epithelial cells. SV-40 transfected human corneal epithelial(HCE) cells were grown to 70% confluency in culture. Serum-free medium was added to cells and the cells incubated for 1, 2, 3, or 6 days. Apoptosis of cells at different times was assessed by staining cells with Giemsa or Hoechst 33342 and measuring DNA fragmentation using the TUNEL assay. HCE cells exposed to serum-free medium demonstrated a high incidence of apoptosis, which increased over time to $50{\pm}4%$ after 3 days. They also stained positively with TUNEL assay. Serum-free medium caused time dependent apoptosis of HCE cells. Thus, serum-like nutrient might be important in corneal epithelial cell homeostasis.

• Journal of The Korean Ophthalmological Society
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• v.59 no.11
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• pp.1056-1061
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• 2018

Purpose: To investigate the effects of valproic acid on the survival of cultured human Tenon's capsule fibroblasts (HTFBs). Methods: Primary cultured HTFBs were exposed to 0, 0.25, 0.5, and 1.0 mM valproic acid with or without 0, 1.0, $2.5{\mu}g/mL$ mitomycin C, and incubated for 5 days. Cell survival was assessed using an MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) assay and the degree of apoptosis was assessed by flow cytometry using annexin-V/propidium iodide double staining. Results: Valproic acid decreased the survival of HTFBs in a dose-dependent manner, and survival was further decreased by adding mitomycin C to valproic acid. Both valproic acid and mitomycin C induced apoptosis of HTFBs. Valproic acid induced less apoptosis than mitomycin C. Conclusions: Valproic acid decreased the cellular survival of HTFBs and induced apoptosis. The antiproliferative effects of valproic acid were further enhanced by the addition of mitomycin C.

• The Journal of the Korea Contents Association
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• v.12 no.2
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• pp.339-348
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• 2012

Acute promyelocytic leukemia (APL) is a cancer of the blood and bone marrow. Although all-trans retionic acid (ATRA) is the agents for ALP therapy, there are various side effects. For overcome this problem, we need the development of new therapeutic agents for APL. A number of bacteria produce various virulence factors with cytotoxic effects on human cancer cells. To understand the anti-cancer effect of Listeria monocytogenes on APL, we examined alteration of the cell viability, apoptosis and cell cycle arrest of the human promyelocytic leukemia cell line, HL-60 cells. The cell supernatant (LmSup) and the extract of L. monocytogenes (LmE) inhibited the cell viability and induced apoptosis of HL-60 cells. These cytotoxic effect of LmSup and LmE mediated by modulation of cell cycle and ROS production. These results indicate that released or included bacterial molecules from L. monocytogenes have a cytotoxicity in HL-60 cells. Therefore, LmSup and LmE may be used as the potential target for the treatment of cancer induced by HL-60 cells.

• Journal of Life Science
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• v.12 no.2
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• pp.182-187
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• 2002

In this study we have investigated the effect of Caesalpina sappann L. extracts on the apoptosis in NIH3T3 cells exposed to methylmethan sulfonate (MMS), an alkylating agent. MTT assay study showed that Caesalpina sappan L. extracts potentiate the MMS-induced viability. Cell morphology studies, acridine orange (AO) staining, and DNA fragmentation analysis indicated that the postincubation of Caesalpina sappan L. extracts increase the nuclear condensation of MMS-induced apoptotosis. These results suggest that Caesalpina sampan L. extracts contain components potentiating MMS-induced apoptosis of NIH3T3 cells.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.230-236
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• 2015

Dermatophagoides pteronissinus (DP) is one of the house dust mites (HDM) associated with allergic diseases. The cysteine protease Der p 1 from DP is a powerful allergen. The pathogenic mechanism of allergy is involved in cytokine secretion of lymphocytes and spontaneous apoptosis of neutrophils. In this study, we investigated whether Der p 1 induces cytokine secretion of lymphocytes and if the release of cytokines is associated with regulation of neutrophil apoptosis. In normal and allergic subjects, Der p 1 increased IL-6, IL-8, MCP-1, and GM-CSF release in a time-dependent course. Supernatants collected from normal and allergic neutrophils after Der p 1 stimulation suppressed the apoptosis of normal and allergic neutrophils, although Der p 1 alone has no effect on neutrophils. Der p 1 suppressed neutrophil apoptosis in coculture of normal neutrophils with normal lymphocytes. Der p 1 more strongly suppressed apoptosis of allergic neutrophils cocultured with allergic lymphocytes than normal neutrophils cocultured with normal lymphocytes. In summary, Der p 1 increases the secretion of cytokines, which has anti-apoptotic effects on neutrophils of normal and allergic subjects. These results will contribute to elucidate the pathogenic mechanism of allergic diseases.