• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.418-422
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• 2015

In the course of screening for novel cell cycle inhibitors and apoptotic inducers, CR389, elucidated as 5-(1H-benzoimidazol-2-yl)-1H-pyridin-2-one, was generated as a new hit compound. Flow cytometric analysis and western blots of PA-1 cells treated with $60{\mu}M$ CR389 revealed an appreciable cell cycle arrest at the G2/M phase through direct inhibition of the CDK1 complex. In addition, activation of p53 via phosphorylation at Ser15 and subsequent up-regulation of p21^CIP1 showed that CR389 also induces p53-dependent-p21^CIP1-mediated cell cycle arrest. Furthermore, apoptotic induction in $60{\mu}M$ CR389-treated PA-1 cells is associated with the release of cytochrome c from mitochondria through up-regulation of the proapoptotic Bax protein, which results in the activation of procaspase-9 and -3, and the cleavage of poly(ADP-ribose) polymerase (PARP). Accordingly, CR389 seems to have multiple mechanisms of antiproliferative activity through p53-mediated pathways against human ovarian cancer cells. Therefore, we conclude that CR389 is a candidate therapeutic agent for the treatment of human ovarian cancer via the activation of p53.

• YAKHAK HOEJI
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• v.46 no.1
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• pp.18-23
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• 2002

Ailanthus altissima has been used to settle an upset stomach, to alleviate a fever and as an insecticide. We reported that the water extract of A. altissima induced apoptotic cell death in Jurkat T-acute Iymphoblastic leukemia cells. Here, we showed the dose-dependent inhibitions of cell viability by the extract, as measured by cell morphology. The cell cycle control genes are considered to play important roles in tumorigenesis. The purpose of the present study is also to investigate the effect of A. altissima on cell cycle progression and its molecular mechanism in the cells. The level of p21 protein was increased after treatment of the extract, whereas both Bcl-2 and Bax protein levels were not changed. These results suggest that A. altissima induces apoptotic cell death via p21-dependent signaling pathway in Jurkat cells which delete wild type p53. Gl checkpoint related gene products tested (cyclin D3, cyclin dependent kinase 4, retinoblastoma, E2Fl) were decreased in their protein levels in a dose-dependent manner after treatment of the extract Taken together, these results indicate that the increase of apoptotic cell death by A. altissima may be due to the inhibition of cell cycle in Jurkat cells.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.890-894
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• 2001

The isolation of genomic DNA from mammalian cells is usually performed by cell lysis followed by protein digestion, extraction, and finally, ethanol precipitation of the chromosomal DNA. However, in the case of large sample numbers or when only small amounts of starting materials are available, such conventional methods are not efficient and are cumbersome to be applied. Some alternative methods have been described as well as having commercial DNA isolation kits to be available, nevertheless, there is room left for much improvement. In the present study, a novel method is introduced, where it simplifies conventional protocols by omitting some time-consuming steps such as protease incubation or DNA precipitation and its resuspension. Using paramagnetic silica resins, the genomic DNA was purified over a magnetic field, and the bound DNA was eluted with a low-salt buffer. The fidelity and effectiveness of this novel method was determined by using normal and apoptotic cells as a starting material and then compared to other protocols. The high speed and convenience along with its high efficiency in detecting apoptotic chromosomal DNA will prove this method to be an improved alternative in the isolation of genomic DNA from mammalian cells.

• Molecules and Cells
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• v.38 no.10
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• pp.918-924
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• 2015

During T cell activation, mitochondrial content increases to meet the high energy demand of rapid cell proliferation. With this increase, the level of reactive oxygen species (ROS) also increases and causes the rapid apoptotic death of activated cells, thereby facilitating T cell homeostasis. Nicotinamide (NAM) has previously been shown to enhance mitochondria quality and extend the replicative life span of human fibroblasts. In this study, we examined the effect of NAM on $CD8^+$ T cell activation. NAM treatment attenuated the increase of mitochondrial content and ROS in T cells activated by CD3/CD28 antibodies. This was accompanied by an accelerated and higher-level clonal expansion resulting from attenuated apoptotic death but not increased division of the activated cells. Attenuation of ROS-triggered pro-apoptotic events and upregulation of Bcl-2 expression appeared to be involved. Although cells activated in the presence of NAM exhibited compromised cytokine gene expression, our results suggest a means to augment the size of T cell expansion during activation without consuming their limited replicative potential.

• 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 Life Science
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• v.26 no.9
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• pp.1015-1021
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• 2016

5-fluorouracil (5-FU), a pyrimidine analog, is a widely used anticancer drug, which works through irreversible inhibition of thymidylate synthase. In the present study, it was investigated the anti-proliferative effects and molecular mechanisms of 5-FU using Ewing's Sarcoma CHP-100 Cells. The present data indicated that treatment of 5-FU to CHP-100 cells induced a G1 phase arrest of the cell cycle in a time-dependent manner. 5-FU-induced G1 arrest was correlated with the accumulation of the hypophosphorylated form of the retinoblastoma protein (pRB) and association of pRB with the transcription factors E2F-1 and E2F-4. Although 5-FU treatment did affect the levels of cyclin-dependent kinases, the levels of cyclin A and B were markedly down-regulated as compared with the untreated control group. In addition, 5-FU-induced G1 arrest of CHP-100 cells was also associated with the induction of apoptosis, as determined by apoptotic cell morphologies, degradation of poly(ADP-ribose) polymerase and Annexin V staining. Furthermore, 5-FU induced the loss of mitochondrial membrane potential with up-regulated pro-apoptotic Bax expression, down-regulated anti-apoptotic Bcl-2 expression and cytochrome c release from mitochondria to cytosol. Collectively, the data suggest that 5-FU is effective in inducing cell growth reduction and apoptosis, in part, by reducing phosphorylation of pRB and activating mitochondrial dysfunction in CHP-100 cells.

• Journal of Life Science
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• v.26 no.10
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• pp.1130-1136
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• 2016

The purpose of this study was to investigate the anti-proliferative and apoptotic effects of acid extract of Gracilaria verrucosa (AEG) on RC-58T/h/SA#4 primary human prostate cancer cells. AEG significantly decreased the cell viability of prostate cancer cells in a dose-dependent manner. AEG also showed relatively low cytotoxicity on normal cell (RWPE-1). The morphology of prostate cancer cells treated with AEG was distorted to shrunken cell masses. In addition, it was revealed that AEG induced cell death as evidenced by increased formation of apoptotic body and nuclear condensation. Furthermore, AEG clearly modulated the down regulation of Bcl-2 (anti-apoptotic)/Bax (pro-apoptotic) family and activated caspase-3 as an effector caspase in a dose-dependent manner. AEG inhibited cell proliferation induced by environmental hormones as a bisphenol A in a dose-dependent manner. These results indicate that AEG act as anti-proliferative effects as a potential therapeutic agent on primary human prostate cancer cells.

• Applied Microscopy
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• v.26 no.3
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• pp.369-377
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• 1996

Ultrastructural changes of chloride cells in the gill from seawater-adapted killifish (Orizias latipes) were studied with a transmission electronmicroscope. Chloride cells contain many mitochondria and specifically developed tubular systems. Apical pits, formed by several neighboring chloride cells, were exposed to the environment. Degeneration and death of the chloride cells by apoptosis occurred more frequently than by necrosis. Apoptotic chloride cells shrank, became to apoptotic bodies, and eventually were phagocytosed and digested by the microphages around them. We conclude that apoptosis plays an important role in increased cellular turnover of chloride cells for the osmoregulation caused by changes in salinity of the environment.

• Imaging Science in Dentistry
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• v.31 no.4
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• pp.227-233
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• 2001

Purpose: The purpose of this study was to investigate the apoptosis induction in tissues constituting the craniofacial region of growing rat by irradiation. Materials and Methods: The submandibular gland, brain, articular cartilage of condylar head, and calvarium were extracted from 20-day-old rats irradiated 10 Gy. Apoptosis of each tissue was examined by DNA fragmentation and estimated quantitatively using apoptotic index on TUNEL assay. Apoptotic index of each tissue was calculated by the equation for apoptotic cells/total cells × 1,000 on the images of confocal laser scanning microscopy. Apoptotic index was analyzed statistically according to the time lapse after irradiation on the tissues. Results : In the submandibular gland, apoptotic index was significantly increased from 6 hours after irradiation showing the highest value at 12 hours and decreased to the control level at 3 days after irradiation. In the brain, apoptotic index was abruptly reached to the maximum value at 6 hours after irradiation and decreased to the control level at 4 days after irradiation. Articular cartilage and calvarium showed no or little apoptotic signals. The results obtained by the apoptotic index accorded with that of DNA fragmentation. Conclusion : Radiation was closely related with the apoptosis of submandibular gland and brain but, not related with the apoptosis of the articular cartilage of condylar head and calvarium. The changes induced by radiation of the hard tissues would not be explained by apoptosis.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.210-213
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• 2005

The suppression of apoptosis during the cell culture might increase recombinant protein production. In the present study, the effects of anti-apoptotic agents on the apoptosis of recombinant Chinese Hamster Ovary cells and the production of Iduronate 2-sulphatase(IDS) were investigated Cell density slightly increased when $2{\mu}M$ of EGCG and $10{\mu}g/mL$ of STR-G were added to culture medium after two days. It was observed that the percentage of apoptotic cells was decreased in the culture with STR-G, and Bcl-2 expression level was enhanced in both culture with STR-G and EGCG. These results suggest that G418 and EGCG are effective anti-apoptotic agents for increasing the productivity of IDS with recombinant CHO-DG44.