• Toxicological Research
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• v.18 no.2
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• pp.183-190
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• 2002

The mechanism by which catechin-mediated cytotoxicity against tumor cells remains to be elusive. To elucidate the mechanical mights of anti-tumor effects, (-)epigallocatechin-gallate (EGCG) of catechin was applied to human prostate cancer DU 145 cells. Cell viability was measured by crystal violet staining. Cell lysates were wed to measure the catalytic activity of caspases by using fluorogenic peptide: Ac-DEVD-AMC for caspase-3 protease, Z-IETD-AFC for caspase-8 protease, Ac-LEHD-AFC for caspase-9 protease as substrates. The equal amounts of protein from cell lysate was separated on SDS-PAGE and analyzed by western blotting with anti-Fas antibody, anti-FasL antibody, anti-BCL2 antibody and anti-Bax antibody. (-)EGCG induced the death of DUl45 cells, which was revealed as apoptosis shown by DNA fragmentation. (-)EGCG induced the activation of caspase family cysteine proteases including caspase-3, -8 and -9 proteases in DU145 cells. Also, (-)EGCG increased the expression of Fas and Fas ligand (FasL) protein in DU145 colls. The expression level of BCL2 was decreased in (-)EGCG treated DU145 cells, whereas Bax protein was increased in a time-dependent manner. We suggest that (-)EGCG-induced apoptosis of DU145 cells is mediated by signaling pathway involving caspase family cysteine protease, mitochondrial BCL2-family protein and Fas/FasL.

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.485-492
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• 2003

The pathological mechanism of impaired spermatogenesis after vasectomy has not been completely investigated. In this study, we examined pathological changes of the testis and the Fas-Fas ligand (FasL) mediated signaling pathway in apoptotic germ cell death after vasectomy in rats. Ten-weeks old Sprague-Dawley rats were underwent bilateral vasectomy and sacrificed after 1 day, 2 days, 3 days, 5 days, 1 week, 2 weeks, and 4 weeks of surgery and the testes were removed. Histopathological evaluation of spermatogenesis was performed by hematoxylin-eosin and periodic acid-Schiff-hematoxylin staining. To elucidate the pathophysiology of seminiferous tubule damage, terminal dUTP nick end labeling staining, electrophoresis assay of DNA fragmentation, and Western blotting analysis for Fas-FasL were performed. Relative weights of testes were decreased from 5 days after vasectomy. Germ cell degeneration were first found in the spermatogonia and spermatocytes at stages I-VI, and XII-XIV seminiferous tubules. Mean incidence of apoptotic germ cells after vasectomy progressively increased to peak in 5 days, and then gradually decreased to the control levels in 2 weeks after vasectomy. The expression of Fas-FasL reached maximum level at 5 days after vasectomy and then declined. In conclusion, impaired spermatogenesis after vasectomy associated with an increase in germ cell apoptasis, which is partly mediated by the activation of Fas-FasL.

• Development and Reproduction
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• v.9 no.2
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• pp.115-121
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• 2005

The present report aimed at evaluating the effect of bisphenol A(BPA) and diethylstilbestrol(DES) on Leydig or Sertoli cell-lines. To identify the differences in the susceptibility to BPA upon different cell-types, assay of the cell viability was done on TM3(Leydig cells) and TM4(Sertoli cells) cell-lines. The result indicates that Sertoli cells are more sensitive to low dose of BPA than Leydig cells. Also, the BPA- or DES-treated Sertoli cells showed a reduction of phospholipase D(PLD) activity identically. According to the confirmation of the mRNA expression of fas receptor and fas ligand in the BPA-treated cells, fas/fasL system activated by BPA will deliver the apoptosis signal onto Sertoli TM4 cells. However, Fas/FasL system was not activated in the DES-treated cells unlike the BPA-treated cells.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.246-252
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• 2002

Purpose : It has been recognized that interaction of the Fas : Fas ligand plays an important role in radiation-induced apoptosis. The purpose of this study was to investigate the role of Fas mutation in radiation-induced apoptosis in vivo. Materials and Method : Mice with mutations in Fas, $MRL/Mpj-Fas^{Ipr}$, and its normal control, MRL/Mpj, were used in this study. Eight-week old male mice were given whole body radiation. After irradiation, the mice were killed and their spleens were collected at different time intervals. Tissue samples were stained with hematoxylin-eosin and the numbers of apoptotic cells were scored. Regulating molecules of apoptosis including p53, Bcl-2, Bax, $Bcl-X_L,\;and\;Bcl-X_S$ were also analyzed by Western blotting. Results : At 25 Gy irradiation, the level of apoptosis reached the peak value at 8 hr after radiation and recovered to the normal value at 24 hr after radiation in MRL/Mpj mice. In contrast, the peak apoptosis level appeared at 4 hr after radiation in $MRL/Mpj-Fas^{Ipr}$. At 8 hr after radiation, the levels of apoptosis in MRL/Mpj mice and $MRL/Mpj-Fas^{Ipr}$ mice were $52.3{\pm}7.8\%\;and\;8.0{\pm}8.6\%$, respectively (p<0.05). The expression of apoptosis regulating molecules, p53, $Bcl-X_L\;and\;Bcl-X_S$, increased in MRL/Mpj mice in response to radiation; p53 with a peak level of 3-fold at 8 h, $Bcl-X_L$ with a peak level of 3.3-fold at 12 h, and $Bcl-X_S$ with a peak level of 3-fold at 12 h after 25 Gy radiation. Bcl-2 and Bax did not show significant change in MRL/Mpj mice. However in $MRL/Mpj-Fas^{Ipr}$ mice, the expression levels of p53, Bcl-2, Bax, $BCl-X_L\;and\;BCl-X_S$ showed no significant change. Conclusion : The level of radiation-induced apoptosis was lower in Fas mutated mice, Ipr, than in control mice. This seemed to be related to the lack of radiation-induced p53 activation in the Ipr mice. This result suggests that Fas plays an important role in radiation-induced apoptosis in vivo.

• The Journal of the Korean bone and joint tumor society
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• v.13 no.2
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• pp.88-95
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• 2007

Purpose: The purpose of this study was to compare the proapoptotic effects of matrix metal-loproteinase inhibitor (MMPI) and doxorubicin on wild-type p53 osteosarcoma cell line, socalled U2OS cell line. Materials and Methods: U2OS cells were treated with MMP inhibitor III (MMPI III) and doxorubicin, either respectively or simultaneously. In cells treated with doxorubicin, Fas-neutralizing antibody so called ZB4 was additionally treated to examine whether the doxorubicin played a role through the Fas/FasL pathway. Cells were analysed regarding to apoptosis and cell death by flow cytometry. Results: U2OS cells incubated with doxorubicin showed significant amount of cell death in dose-dependent manner. However, those incubated with MMPI III mostly remained viable state. In addition, there is no relationship between two drugs. Cells treated with doxorubicin and ZB4 at the same time did not show down regulation of apoptosis through inhibition of Fas/FasL pathway. Conclusion: It is important to re-examine MMP inhibitor's effect on other osteosarcoma cell line with wild-type p14 as well as wild-type p53 to evaluate its proapoptotic effect.

• Journal of Embryo Transfer
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• v.13 no.2
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• pp.179-190
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• 1998

Prolactin (PRL) surge in cycling rats at proestrous afternoon has previously been reported as an inducer of apoptotic cell death of luteal cells. This death-inducing action of PRL seeins unusual, because PRL can he categorized as a cell-survival factor, if other known physiological functions of PRL are taken into account. In this study, the apoptotic action of PRL was assessed in cultured cells prepared from rat luteal tissue and underlying molecular /cellular mechanism of PRL-induced luteolysis was analyzed. The latest crop of corpora lutea (CLs) were enucleated from rat ovaries at 18:00 h on the proestrous day before the next ovulation. Donor rats were pretreated with CB154, a dopamine agonist, in order to he exempted from the endogenous PRL surge. The harvested GLs were dispersed and cultured with or without PRL (2$\mu$g /ml) for 24 or 48 h. An addition of PRL to the culture medium changed the parameters indicative of cell death via apoptosis: a decrease in cell viability (MTT) and an increase in chromatin condensation. Most of the DNA breakdown in nuclei induced by PRL occurred in steroidogenic cells which were identified by 3$\beta$-HSD activity staining, and the number of 3$\beta$-HSD-positivecells were significantly decreased. Interestingly, most of the cells with an apoptotic nucleus adhered to one or more intact and seemingly non-steroidogenic cells. Because the expression of Fas has heen shown to be abundant in murine ovary, and Fas is known to have an exact physiological role in occurrence of apoptotic cell death, the membrane form-Fas ligand (rnFasL) was quantified in the cell lysate. An addition of PRL increased expression of mFasL. Moreover, an addition of concanavalin A (ConA), a T-cell specific activator, in place of PRL, enhanced the apoptotic parameters. Cumulatively, the apoptotic PRL action was addressed to cells unknown than steroidogenic lute~ cells. The most prohable candidate for the direct target cells is Tcells in the luteal tissue that can express mFasL in response to PRL.

• The Journal of Internal Korean Medicine
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• v.24 no.1
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• pp.123-133
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• 2003

Objectives : This study was designed to investigate the effects of Chungganhaeju-tang on expression of alcohol metabolizing enzymes, cell viability and alcohol-induced apoptosis. Materials and Methods : For this study, the human hepatoma cell line HepG2 was used. HepG2 cells were treated with ethanol-or acetaldehyde, chungganhaeju-tang, anti-Fas neutralizing antibody and were investigated by using quantitative RT-PCR, MTT and Trypan blue exclusion assays. Results : The results are summarized as follows: 1. Quantitative RT-PCR analysis demonstrated that ethanol-or acetaldehyde-mediated increase of ALDH gene expression was not affected by Chungganhaeju-tang treatment. 2, Ethanol-or acetaldehyde-induced apoptosis was remarkably inhibited by Chungganhaeju-tang in a dose-dependent manner. 3, Ethanol-or acetaldehyde-induced apoptosis was significantly blocked by anti-FasL neutralizing antibody, suggesting apoptosis induced by alcohol might be mediated by FasL/Fas signaling pathway. Conclusions : Taken all together, these results indicate that the FasL/Fas signaling plays a critical role in alcohol-induced apoptosis and Chungganhaeju-tang increases viability of liver cells by suppression of the FasL/Fas-mediated apoptosis-signaling pathway.

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.756-766
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• 2005

The signaling mechanism underlying aburatubolactam C-induced FasL upregulation was investigated in human Jurkat T cells. After treatment with aburatubolactam C, the src-family PTKs $p56^{lck}\;and\;p59^{fyn}$, and MAP kinases ERK2 and JNK1, were activated prior to FasL upregulation; Both $p56^{lck}\;and\;p59^{fyn}$ were directly activated 2.4- and 2.2-fold, respectively, in vitro by aburatubolactam C. The aburatubolactam C-induced cellular changes, including the activation of ERK2 and INK1, and FasL upregulation, were completely prevented by the PTK inhibitor genistein. The activation of protein kinase C (PKC$\delta,\;\epsilon\;and\;\mu$ was also induced following aburatubolactam C treatment. Although the activation of $p56^{lck}$ and tyrosine phosphorylation of the cellular proteins were not blocked by the PKC inhibitor GFl09203X, the activation of ERK2 was completely abrogated, along with a detectably enhanced JNK1 activation; FasL upregulation, and apoptosis. However, the FasL upregulation and apoptosis were significantly inhibited by the PKC activator PMA, with a remarkable increase in the ERK2 activation. The cytotoxic effect of aburatubolactam C was reduced in the presence of the anti-Fas neutralizing antibody ZB-4. Although ectopic expression of Bcl-2 failed to completely block the cytotoxicity of aburatubolactam C, it was clearly suppressed. The c-Fos mRNA expression was upregulated in a biphasic manner, where the second phasic expression overlapped with the FasL upregulation. Accordingly, these results demonstrate that aburatubolactam C-induced apoptosis is exerted, at least in part, by FasL upregulation dictated by activation of the PTK ($p56^{lck}\;and\;p59^{fyn}$) /JNKI pathway, which is negatively affected by the concurrent activation of the PKC/ERK2 pathway proximal to PTK activation.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5573-5579
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• 2012

Onions (Allium cepa L.) are widely used in the food industry for its nutritional and aromatic properties. Our studies showed that ethyl acetate extract of onion (EEO) had potent inhibitory effects on animal fatty acid synthase (FAS), and could induce apoptosis in FAS over-expressing human breast cancer MDA-MB-231 cells. Furthermore, this apoptosis was accompanied by reduction of intracellular FAS activity and could be rescued by 25 mM or 50 mM exogenous palmitic acids, the final product of FAS catalyzed synthesis. These results suggest that the apoptosis induced by EEO occurs via inhibition of FAS. We also found that EEO could suppress lipid accumulation during the differentiation of 3T3-L1 adipocytes, which was also related to its inhibition of intracellular FAS activity. Since obesity is closely related to breast cancer and obese patients are at elevated risk of developing various cancers, these findings suggested that onion might be useful for preventing obesity-related malignancy.

• Proceedings of the Zoological Society Korea Conference
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• 1999.04a
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• pp.71.1-71
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• 1999

No Abstract, See Full Text