• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.88.1-88.1
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• 2008

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.88.2-88.2
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• 2008

• Journal of Gastric Cancer
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• v.3 no.1
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• pp.38-43
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• 2003

Purpose: Caspase 2, a member of the family of ICE-like proteases, is activated by the Fas pathway and induces apoptosis by triggering the caspase cascade. The purpose of this study was to determine whether the expression pattern of caspase 2 might be associated with gastric cancer development and if so, to determine to which pathologic parameter it is linked. Materials and Methods: For the construction of the gastric cancer tissue microarray, 78 paraffin-embedded tissues containing gastric cancer areas were cored 3 times and transferred to the recipient master block. The expression pattern of caspase 2 was examined on tissue microarray slides by using immunohistochemistry and was compared with pathologic parameters, including histologic type, depth of invasion, lymph node metastasis, and peritoneal dissemination. Results: Caspase 2 was expressed on superficial and foveolar epithelial cells and lymphocytes in the gastric mucosa, mainly in cytoplasm. We found loss of caspase 2 expression in 41 ($52.6\%$) of the 78 gastric cancer tissues. Statistically, histologic type and other pathologic parameters were not related with loss of caspase 2 expression Conclusion: Our findings provide enough evidence that loss of caspase 2 expression may contribute to the development of Korean gastric cancer and that it might be one of the possible escape mechanisms from apoptosis in gastric cancer.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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• pp.231-243
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• 1998

In the present study, we provide evidence that ginsenoside $Rh_2$ (G-$Rh_2$) as well as staurosporine induces apoptosis of human hepatoma SK-HEP-1 cells by caspase 3-mediated processing of $p21^{WAFI/CIPI}$ in the early stage of apoptosls. Immunoblottings showed that G-$Rh_2$ as well as statrosporine induced the processing of caspase-3 to an active form, pl7. In stable Bcl-2 transfectants however, G-$Rh_2$ induced DNA fragmentation, while staurosporine did not. In the early stage of apoptosis, $p21^{WAFI/CIPI}$ was detected to undergo proteolytic processing specifically conducted by caspase-3. $p21^{WAFI/CIPI}$ translated in vitro was cleaved into a p14 fragment, when incubated with cell extracts obtained from either G-$Rh_2$- or staurosporine-treated cells. Cleavage was equally inhibited in both cases by adding Ac-DEVD-cho, a specific caspase-3 inhibitor, but not by Ac-YVkD-cho, a specific caspase-l inhibitor. Similarly, $p21^{WAFI/CIPI}$ was efficiently leaved by recombinant caspase-3 overexpressed in E. coli. Moreover, the endogenous $p21^{WAFI/CIPI}$ of untreated-cell extracts was also cleaved by recombinant caspase-3. Mutation analysis allowed identification of two caspase-3 cleavage sites, $DHVD^{112}$/L and $SMTD^{149}$/F, which are located within, or near the interaction domains for cyclins, Cdks, and PCNA. Taken together, these results show that G-$Rh_2$ as well as staurosporine increases caspase-3 activity, which in turn directly cleaves $p21^{WAFI/CIPI}$ resulting in elevation of Cdk kinase activity in the early stages of apoptosis. We propose that proteolytic cleavage of $p21^{WAFI/CIPI}$ is a functionally relevant event that allows unleashing the cyclin/Cdk activity from the inhibitor seen in the earlier stage of apoptosis, the event of which may be associated with the triggering mechanism for the execution of apoptosis.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.911-917
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• 2009

The apoptotic caspases have been classified in accordance with their substrate specificities, as the optimal tetrapeptide recognition motifs for a variety of caspases have been determined via positional scanning substrate combinatorial library technology. Here, we focused on two proteolytic recognition motifs, DEVD and IETD, owing to their extensive use in cell death assay. Although DEVE and IETD have been generally considered to be selective for caspase-3 and -8, respectively, the proteolytic cleavage of these substrates does not display absolute specificity for a particular caspase. Thus, we attempted to monitor the cleavage preference for caspase-3, particularly using the recombinant protein substrates. For this aim, the chimeric GST:DEVD:EGFP and GST:IETD:EGFP proteins were genetically constructed by linking GST and EGFP with the linkers harboring DEVD and IETD. To our best knowledge, this work constitutes the first application for the monitoring of cleavage preference employing the recombinant protein substrates that simultaneously allow for mass and fluorescence analyses. Consequently, GST:IETD:EGFP was cleaved partially in response to caspase-3, whereas GST:DEVD:EGFP was completely proteolyzed, indicating that GST:DEVD:EGFP is a better substrate than GST:IETD:EGFP for caspase-3. Collectively, using these chimeric protein substrates, we have successfully evaluated the feasibility of the recombinant protein substrate for applicability to the monitoring of cleavage preference for caspase-3.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.114-117
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• 2002

During the screening of inhibitors of caspase-3 induction in U937 human monocytic leukemia cells from natural sources, Forsythiae fructus, which showed a high level of inhibition, was selected. And then, the compound was purified from the methanol extract using silica gel column chromatography and HPLC. The inhibitor was identified as rengyolone, by spectroscophic methods of ESI-MS, $^1H-NMR$, $^{13}C-NMR$, DEPT, and HMBC. Rengyolone showed inhibitory activity of caspase-3 induction, a major protease of apoptosis cascade, with an $IC_{50}$ value of $6.25\;{\mu}g/mL$ after 7 h of treatment in U937 cells. It also showed inhibitory activity of caspace-1 induction, with an $IC_{50}$ value of $7.50\;{\mu}g/mL$ after 40 h of treatment in D10S cells. In addition, it showed protective effect against cell death with an $IC_{50}$ value of $11\;{\mu}g/mL$ on U937 cells induced by etoposide after 24 h of treatment, but did not show any cytotoxicity at the same condition without etoposide, a caspase 3 inducing agent.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4095-4099
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• 2013

Oxidative stress induces apoptosis in many cellular systems including glioblastoma cells, with caspase-8 activation was regarded as a major contribution to $H_2O_2$-induced cell death. This study focused on the role of the autophagic protein p62 in $H_2O_2$-induced apoptosis in U87MG cells. Oxidative stress was applied with $H_2O_2$, and cell apoptosis and viability were measured with use of caspase inhibitors or autophagic mediators or siRNA p62, GFP-p62 and GFP-p62-UBA (del) transfection. We found that $H_2O_2$-induced U87MG cell death was correlated with caspase-8. To understand the role of p62 in MG132-induced cell death, the levels of p62/SQSTM1 or autophagy in U87MG cells were modulated with biochemical or genetic methods. The results showed that the over-expression of wild type p62/SQSTM1 significantly reduced $H_2O_2$ induced cell death, but knockdown of p62 aggravated the process. In addition, inhibition of autophagy promoted p62 and active caspase-8 increasing $H_2O_2$-induced apoptosis while induction of autophagy manifested the opposite effect. We further demonstrated that the function of p62/SQSTM1 required its C-terminus UBA domain to attenuate $H_2O_2$ cytotoxity by inhibition of caspase-8 activity. Our results indicated that p62/SQSTM1 was a potential contributor to mediate caspase-8 activation by autophagy in oxidative stress process.

• Physical Therapy Korea
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• v.11 no.2
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• pp.47-63
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• 2004

In most tissues, apoptosis plays a pivotal role in normal development and in regulation of cell number. Therefore inappropriate apoptosis is revealed in a variety of diseases. This study was carried out to investigate the effects of acupuncture and needle electrode electrical stimulation on the change of caspase-3, 9 and neuronal nitric oxide synthase (nNOS) immunoreactive cells in the sprague dawley rats (SD rat). In immobilized SD rats (n=5), enhanced caspase-3 and caspase-9 expression were detected in the reticular part of substantia nigra, and enhanced nNOS was detected in the dorsolateral periaqueductal gray (DL-PAG) of midbrain and the paraventricular nucleus (PVN) of the hypothalamus using immunohistochemistry. Following the immobilization, acupuncture (n=5) and needle electrode electrical stimulation (n=5, 2 Hz) was applied at H$\acute{e}$g$\breve{u}$ (LI4) acupoint of SD rats, respectively. The stress-induced enhancement in the expression of caspase-3, 9 and nNOS were The present results demonstrate that and needle electrode electrical stimulation are effective in the modulation of expression of caspase-3, 9 and nNOS induced by immobilization.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.4849-4852
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• 2015

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been investigated as an effective agent to treat various cancers. Cancer stem cells are resistant to TRAIL treatment, but the mechanism of TRAIL resistance remains unknown. In this study, brain cancer stem cells were isolated by CD133 magnetic sorting, and the number of CD133 positive cells detected by flow cytometry. The self-renewing capacity of brain cancer stem cells was examined by a neurosphere formation assay, and the percentage of cell death after TRAIL treatment was examined by an MTS assay. Expression of DR5, FADD, caspase 8 and BCL2 proteins was detected by western blot. The amount of CD133 positive cells was enriched to 71% after CD133 magnetic sorting. Brain cancer stem cell neurosphere formation was significantly increased after TRAIL treatment. TRAIL treatment also reduced the amount of viable cells and this decrease was inhibited by a caspase 8 inhibitor or by the pan-caspase inhibitor z-VAD (P<0.05). Brain cancer stem cells expressed lower levels caspase 8 protein and higher levels of BCL2 protein when compared with CD133 negative cells (P<0.05). Our data suggest that TRAIL resistance is related to overexpression of BCL2 and low expression of caspase 8 which limit activation of caspase 8 in brain cancer stem cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.802-810
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• 2005

The tetrahydroisoquinolines included potent cytotoxic agents that showed antitumor activity,antimicrobial activity, and other biological properties. We studied the effect of CDST, 1-Chloromethyl-6,7-dimethoxy-3,4-dihydro-1H-isoquinoline-2-sulfonic acid amide, a newly synthesized anti-cancer agent. The cytotoxic activity of CDST in HL-60 cells was increased in a dose-dependent manner. CDST, tetrahydroisoquinolines derivative, was cytotoxic to HL-60 cells, with IC50 of $80{\mu}g/ml$. Treatment of CDST to HL-60 cells showed the fragmentation of DNA in a dose- and time dependent manner, suggesting that thesecells underwent apoptosis. Treatment of HL-60 cells with CDST was induced in a dose- and time-dependent activation of caspase-3, caspase-8 and proteolytic cleavage of poly(ADP-ribose) polymerase. In caspase activity assay, caspase-3 and -8 was activated after 12 h and 6 h posttreatment, respectively. CDST also caused the release of cytochrome c from mitochondria into the cytosol. CDST-induced cytochrome c release was mediated by caspase-8-dependent cleavage of Bid and Bax translocation. These results suggest that caspase-8 induced Bid cleavage and Bax translocation, caused mitochondrial cytochrome c release, and induce caspase-3 activationduring CDST-induced apoptosis in HL-60 cells.