• BMB Reports
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• 제34권3호
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• pp.189-193
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• 2001

Curcumin a yellow pigment from Curcuma Tonga, has been known to possess antioxidative and anticarcinogenic properties, as well as to induce apoptosis in some cancer cells. There have been, however, several contradictory reports that hypothesized curcumin (a hydrophobic molecule) can bind a membrane Gpid bilayer and induce nonspecific cytotoxicity in some cell lines. Why curcumin shows these contradictory effects is unknown. In A-431 cells, growth inhibition by curcumin is due mostly to the specific inhibition of the intrinsic tyrosine kinase activity of the epidermal growth factor receptor, as reported earlier by Korutla et al. Thus, we assumed that the cell death of A-431 by curcumin might be due to the specific induction of apoptosis. In this paper we clearly show that curcumin induces apoptosis in A-431 cells. The cureumin-induced cell death of A-431 exhibited various apoptotic features, including DNA fragmentation and nuclear condensation. Furthermore, the curcumin-induced apoptosis of A-431 cells involved activation of caspase-3-like cysteine protease. Involvement of caspase-3 was further confirmed by using a caspase-3 specific inhibitor, DEVD-CHO. In another study, decreased nitric oxide (NO) production was also shown in A-431 cells treated with curcumin, which seems to be the result of the inhibition of the iNOS expression by curcumin, as in other cell lines. However, 24 h after treatment of curcumin there was increased NO production in A-431 cells. This observation has not yet been clearly explained. We assumed that the increased NO production may be related to denitrosylation of the enzyme catalytic site in caspase-3 when activated. Taken together, this study shows that the cell death of A-431 by curcumin is due to the induction of apoptosis, which involves caspase-3 activation.

• Applied Biological Chemistry
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• 제44권1호
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• pp.1-6
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• 2001

본 연구에서는 Ttichoplusia ni 세포의 apoptosis 유도 및 억제 현상의 기초연구를 수행하였다. Apoptosis 유도제로 알려진 hygromycin B에 의한 세포 성장 저해는 $200\;{\mu}/ml$의 수준에서부터 나타났고, $400\;{\mu}/ml$ hygromycin B를 처리한 세포에서는 배양 후 2일부터 DNA가 분절되어지는 것을 확인할 수 있었다. 그러나 dexamethasone과 sodium butyrate를 첨가시 세포성장은 저해되었지만 DNA 분절현상이 보이지 않아 apoptosi의 유발여부를 확인할 수 없었다. 그리고 caspase 기능억제제의 apoptosis 지연효과를 보기 위해 $200\;{\mu}/ml$ hygromycin B로 apoptosis를 유발한 상태에서 Ac-DEVD-CHO를 첨가하여 세포성장을 비교해 본 결과 이 저해제에 의해 약 36%정도 apoptosis가 억제되었음을 확인하였다. N-acetylcysteine의 경우도 apoptosis지연 효과가 있었다. Bcl_계에 속하는 anti-apoptotic 유전자의 발현연구로서 apoptosis 저해 단백질인 bcl-2 유전자를 곤충세포에 형질전환시킨 후 이 단백질이 한시적으로 발현되는 것을 western blot분석법으로 확인하였으며 apoptosis가 지연된 곤충세포주의 개발이 가능하다는 결론을 보였다.

• Journal of Nutrition and Health
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• 제36권8호
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• pp.828-833
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• 2003

Dially disulfide (DADS), a component of garlic (Allium sativum), has been known to exert potent chemopreventive activity against various cancers. In this study, the synergistic effect of DADS and daunorubicin on the cytotoxicity of HL-60 cells, a human leukemia cell line, was investigated. DADS at 25 M greatly potentiated daunorubicin-induced cell death, decreasing cell viabilityto50%ofthe control. Daunorubicin-induced apoptosis was accompanied by the activation of caspase-3, the degradation of poly-(ADP-ribose) polymerase (PARP) and D4-GDI, and DNA fragmentation, which were blocked by pre-treatment with acetyl-Asp-Glu-Val-Asp- dialdehyde (Ac-DEVD-CHO). Treatment that combined 25 M DADS and 100 nM daunorubicin caused a similar degree of caspase-3 activation, PARP and D4-GDI degradation, and DNA fragmentation to that caused by treatment with 250 nM daunorubicin alone. These results indicate that combined therapy using daunorubicin with DADS, a component of food, and garlic can effectively decrease the therapeutic dose of daunorubicin, preventing the severe side effects of daunorubicin.

• Archives of Pharmacal Research
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• 제26권11호
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• pp.937-942
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• 2003

Nitric oxide(NO) induces apoptosis in human osteoblasts. Treatment with exogenous NO donors, SNAP (S-Nitroso-N-acelylpenicillamine) and SNP (sodium nitroprusside), to MG-63 osteoblasts resulted in apoptotic morphological changes, as shown by a bright blue-fluorescent condensed nuclei and chromatin fragmentation by fluorescence microscope of Hoechst 33258-staining. The activities of caspase-9 and the subsequent caspase-3-like cysteine proteases were increased during NO-induced cell death. Pretreatment with Z-VAD-FMK (a pancaspase inhibitor) or Ac-DEVD-CHO (a specific caspase-3 inhibitor) abrogated the NO-induced cell death. The NO donor markedly activated JNK, a stress-activated protein kinase in the human osteoblasts. This study showed that the inhibition of the JNK pathway markedly reduced NO-induced cell death. But neither PD98059 (MEK inhibitor) nor SB203580 (p38 MAPK inhibitor) had any effect on NO-induced death. Taken together, these results suggest that JNK/SAPK may be related to NO-induced apoptosis in MG-63 human osteoblasts.

• 한국환경성돌연변이발암원학회지
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• 제24권3호
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• pp.113-120
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• 2004

Chromium compounds are known human and animal carcinogens. In this study, the effects of sodium chromate on apoptosis and cell cycle were investigated in order to unveil the elements of early cellular responses to the metal. Using Chinese hamster ovary cells(CHO-K1-BH4), we found taht chromium (VI) treatment induced apoptosis in these cells, as signified by nuclear fragmentation, DNA laddering on agarose gel electrophoresis, and an increased proportionof cells with hypodiploid DNA. Preceding these changes, chromium (VI) treatment increased caspase 3 pritease activity and also increased expression of p53 protein, while the level of bcl2 protein was not changed. Coincubation with caspase inhibitor, Z-DEVD-FMK, inhibited chromium-induced apoptosis. In the flow cytometric analysis using propidium iodide fluorescence, an increase of cell population in G2/M phase was shown in cells exposed to at least 160 $\mu\textrm{m}$ of sodium chromate for 72h, form 9.8% for 0$\mu\textrm{m}$ chromium (VI) to 26.4% for 320$\mu\textrm{m}$ chromium(VI). Taken together, these findings suggest that chromium(VI)-induced apoptosis is accompanied by G2/M cell cycle arrest, and that p53-mediated pathway may be involved in positive regulation of G2/M arrest and a concurred apoptosis in CHO cells.

• 대한치과교정학회지
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• 제33권6호
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• pp.453-463
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• 2003

본 연구는 MC3T3El 조골세포가 저산소증에 반응하여 유발될 수 있는 세포 고사조절 기전을 구명하고자 함에 목적이 있다. $2\%$ 저산소증의 조건하에서 MC3T3El 조골세포는 DNA 사다리 분절 헝성을 보였으며 형광성 염료인 Hoechst 33258로 염색된 핵 구조 형태 관찰시 시간이 지남에 따라 세포고사 현상을 관찰할 수 있었다 Pancaspase 억제제인 Z-VAD-FMK나 특정한 caspase-3 억제제인 Z-DEVD-CHO로 사전 처치하였을 경우에는 저산소증에 의한 DNA 사다리 분절형성이 농축에 비례하여 억제되었다. caspase-3류의 프로테아제(DEVDase) 활성 증가가 세포고사 중에 관찰되었으나 caspase-1 (YVADase)의 활성은 없었다. 어떤 caspase가 세포고사에 관여하는지를 확인하기 위하여 anti-caspase-3 또는 anti-caspase-6의 항체를 이용한 western blotting이 시행되었다. caspase-3의 활성산물에 해당하는 17-KDa단백질과 caspase-6의 활성산물인 20-KDa 단백질이 세포용해물에서 발생되었다. 또한 시간 경과와 더불어 caspase-6의 활동의 상징인 Lamin A의 분열을 일으켰으며, 사이토크롬 C를 cytosol로 방출하였다. 이로써 저산소증에 의한 조골세포의 고사 과정에 사이토크롬 C의 방출이 포함된 caspase의 활성이 관여한다는 것을 확인할 수 있었다.

• Archives of Pharmacal Research
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• 제27권11호
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• pp.1147-1153
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• 2004

Bladder cancer is a common cancer with high risk of recurrence and mortality. Intravesicle chemotherapy after trans-urethral resection is required to prevent tumor recurrence and progression. It has been known that antioxidants enhance the antitumor effect of bacillus Calmette-Guerin (BCG), the most effective intravesical bladder cancer treatment. Capsaicin, the major pungent ingredient in genus Capsicum, has recently been tried as an intravesical drug for overactive bladder and it has also been shown to induce apoptotic cell death in many cancer cells. In this study, we investigated the apoptosis-inducing effect and alterations in the cellular redox state of capsaicin in MBT-2 murine bladder tumor cells. Capsaicin induced apoptotic MBT-2 cell death in a time- and dose-dependent manner. The capsaicin-induced apoptosis was blocked by the pretreatment with Z-VAD-fmk, a broad-range caspase inhibitor, or Ac-DEVD-CHO, a caspase-3 inhibitor. In addition to the caspase-3 activation, capsaicin also induced cytochrome c release and decrease in Bcl-2 protein expression with no changes in the level of Bax. Furthermore, capsaicin at the concentration of inducing apoptosis also markedly reduced the level of reactive oxygen species and lipid peroxidation, implying that capsaicin may enhance the antitumor effect of BCG in bladder cancer treatment. These results further suggest that capsaicin may be a valuable intravesical chemotherapeutic agent for bladder cancers.

• Molecules and Cells
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• 제26권2호
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• pp.152-157
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• 2008

Caspases play critical roles in the execution of apoptosis. Caspase-3 and caspase-7 are closely related in sequence as well as in substrate specificity. The two caspases have overlapping substrate specificities with special preference for the DEVD motif. However, they are targeted to different subcellular locations during apoptosis, implying the existence of substrates specific for one or other caspase. To identify new caspase-7 substrates, we digested cell lysates obtained from the caspase-3-deficient MCF-7 cell line with purified recombinant caspase-7, and analyzed spots that disappeared or decreased by 2-DE (we refer to this as the caspase-7 degradome). Several proteins with various cellular functions underwent caspase-7-dependent proteolysis. The substrates of capase-7 identified by the degradomic approach were rather different from those of caspase-3 (Proteomics, 4, 3429-3435, 2004). Among the candidate substrates, we confirmed that Valosin-containing protein (VCP) was cleaved by both capspase-7 and caspase-3 in vitro and during apoptosis. Cleavage occurred at both $DELD^{307}$ and $DELD^{580}$. The degradomic study yielded several candidate caspase-7 substrates and their further analysis should provide valuables clues to the functions of caspase-7 during apoptosis.

• 대한본초학회지
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• 제22권2호
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• pp.35-43
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• 2007

Objectives : The purpose of this study was to investigate the effect of Bo-du-san (BOS) on apoptosis in human gastric cancer cells, SNU-l cells. BOS, a drug preparation consisting of two herbs, that is, Crotonis Fructus (Strychni ignatii Semen, bodu in Korean) and Glycyrrhizae Radix (Glycyrrhizae uralensis FISCH, Gamcho in Korean). Methodss : In this study, methanol extract of BOS was examined for cytotoxic activity on human gastric cancer cells, SNU-1 cells, using XTT assay, with an IC50 value was 0.7 mg/ml and 0.3 mg/ml at 24 hrs and 48 hrs, respectively. Apoptosis induction by BDS in SNU-l cells was verified by the induction of DNA fragmentation, cleavage of poly ADP-ribose polymerase (PARP), and activation of caspase-3, -8 and -9. Inhibitors of caspase-3, -8 and -9 (Ac-DEVD-CHO, Z-IETD-FMK and Z-LEHD-FMK) efficiently blocked BOS-induced cell death of SNU-l. Resultss : BOS-induced cell death was via caspase dependent apoptosis. Moreover, treatment of BOS result in the decrease the G1/S cycle regulation proteins (cyclin D1 and E) expression and increase CDK inhibitor proteins (p21 and p27) expression, and increase apoptotic protein, p53 expression. Thus, BOS induces apoptosis in SNU-1 cells via cell cycle arrested in G1 phase. Conclusions : These results indicated that BOS has some potential for use as an anti-cancer agent.

• The Korean Journal of Physiology and Pharmacology
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• 제7권4호
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• pp.199-205
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• 2003

Osteoblasts are affected by TNF-${\alpha}$ overproduction by immune cells during inflammation. It has been suggested that functional $NF-{\kappa}B$ sites are involved in TNF-${\alpha}$-induced bone resorption. Thus, we explored the effect of pyrrolidine dithiocarbamate (PDTC), which potently blocks the activation of nuclear factor $(NF-{\kappa}B)$, on the induction of TNF-${\alpha}$-induced activation of JNK/SAPK, AP-1, cytochrome c, caspase and apoptosis in MC3T3E1 osteoblasts. Pretreatment of the cells with PDTC blocked TNF-${\alpha}$-induced $NF-{\kappa}B$ activation. TNF-${\alpha}$-induced activation of AP-1, another nuclear transcription factor, was suppressed by PDTC. The activation of c-Jun N-terminal kinase, implicated in the regulation of AP-1, was also down regulated by PDTC. TNF-${\alpha}$-induced apoptosis, release of cytochrome c and subsequent activation of caspase-3 were abolished by PDTC. TNF-${\alpha}$-induced apoptosis was partially blocked by Ac-DEVD-CHO, a caspase-3 inhibitor, suggesting that caspase-3 is involved in TNF-${\alpha}$-mediated signaling through $NF-{\kappa}B$ in MC3T3E1 osteoblasts. Thus, these results demonstrate that PDTC, has an inhibitory effect on TNF-${\alpha}$-mediated activation of JNK/SAPK, AP-1, cytochrome c release and subsequent caspase-3, leading to the inhibition of apoptosis. Our study may contribute to the treatment of TNF-${\alpha}$-associated immune and inflammatory diseases such as rheumatoid arthritis and periodontal diseases.