• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.731-745
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• 2005

Cyclosproin A(CsA)는 세포 이식거부방지를 위한 면역 억제제 및 자가 면역질환 치료제로 널리 사용되어 왔다. CsA는 매양된 사람 치은섬유아세포를 증식시킴이 알려져 있지만 CsA에 의한 세포증식기전에 대한 세포사멸기전 및 Bcl-2의 역할은 연구되어 있지 않다. 이번 연구는 사람 섬유아세포에서 CsA에 의한 세포증삭기전에 세포고사기전 및 Bcl-2 family가 관여하는지 밝히는 데에 목적이 있다. 세포 생장력은 MTT 방법으로 측정하였다. Bcl-2 family와 Fas 발현 정도는 RT-PCR 방법이나 western blot으로 확인하였다. Caspase-3 및 -9의 활성은 ELISER reader로, reactive oxygen species(ROS)는 fluorescence spectrometer에 의해 측정되었다. 미토콘드리아에서 세포질로 분비된 cytochrome c는 Western blot으로 조사하였다. CsA는 $0.1{\sim}10\;{\mu}M$에서 사람 섬유아세포의 생존률을 시간과 농도 의존적으로 증가시켰으며, 50 ${\mu}M$ CsA에서는 오히려 세포가 죽였다. 또한, CsA 처리로 미토콘드리아에서 세포질로 유리되는 cytochrome c 양과 VDAC 1 및 3 발현량이 감소되었고, caspase-9과 caspase-3의 활성도도 감소되었다. 한편, CsA 처리한 섬유아세포에서 death receptor 구성요소인 Fas 발현이 감소되었다. Bcl-2 family에 대한 RT-PCR, western blot 분석결과, 세포고사를 억제하는 Bel-2 발현은 증가되었으나 세포고사를 자극하는 Bax와 Bid의 발현은 감소되었다. 이러한 결과들은 사람 섬유아세포에서 CsA유도 세포증식에 Bcl-2 family와 ROS가 매개하는 미토콘드리아 의존 및 death receptor 의존 세포고사기전이 관여함을 시사하였다.

• Journal of Life Science
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• v.17 no.8 s.88
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• pp.1063-1067
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• 2007

The Bcl-2 family proteins play critical roles in regulation of apoptosis, and the balanced interaction of pro- and anti-death members is a key factor in determining the cell fate. Noxa, a BH3-only Bcl-2-family member, has been originally identified as a target gene of p53. To understand the mechanism by which human Noxa (hNoxa) regulates the cell death, we screened the hNoxa binding partner using the yeast two hybrid screening and found that anti-death protein Mcl-1 binds to hNoxa. The binding of hNoxa to Mcl-1 was confirmed by immunoprecipitation in human colon cancer cell line HCT 116 cells. Mcl-1 significantly inhibited the hNoxa-induced cell death in HCT 116 cells. During the cell death induced by hNoxa, Mcl-1 protein was degraded. Its degradation was inhibited by z-VAD-fmk, a pancaspase inhibitor, suggesting caspase is responsible for Mcl-1 degradation in response to hNoxa. Together, the results indicate that hNoxa binds to Mcl-1 that is degraded by cas-pases during hNoxa-induced cell death.

• Molecules and Cells
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• v.21 no.1
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• pp.1-6
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• 2006

Bcl-2/adenovirus E1B 19 kDa-interacting protein 3 (BNIP3) is a mitochondrial pro-apoptotic protein that has a single Bcl-2 homology 3 (BH3) domain and a COOH-terminal transmembrane (TM) domain. Although it belongs to the Bcl-2 family and can heterodimerize with Bcl-2, its pro-apoptotic activity is distinct from those of other members of the Bcl-2 family. For example, cell death mediated by BNIP3 is independent of caspases and shows several characteristics of necrosis. Furthermore, the TM domain, but not the BH3 domain, is required for dimerization, mitochondrial targeting and pro-apoptotic activity. BNIP3 plays an important role in hypoxia-induced death of normal and malignant cells. Its expression is markedly increased in the hypoxic regions of some solid tumors and appears to be regulated by hypoxia-inducible factor (HIF), which binds to a site on the BNIP3 promoter. Silencing, followed by methylation, of the BNIP3 gene occurs in a significant proportion of cancer cases, especially in pancreatic cancers. BNIP3 also has a role in the death of cardiac myocytes in ischemia. Further studies of BNIP3 should provide insight into hypoxic cell death and may contribute to improved treatment of cancers and cardiovascular diseases.

• Journal of Society of Preventive Korean Medicine
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• v.16 no.1
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• pp.71-80
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• 2012

Objective : The aim of this study is to evaluate anti-cancer effects of $Ampelopsisradix$ Extract (AE) on human lung cancer A549 cells. Method : The apoptotic activities and cell growth arrest activities of AE were measured using 3-[4,5-dimethyl-thiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The molecules involved in apoptotic process were assessed by western blotting. Result : Treatment of AE potently reduced cell viability in a dose-dependent manner in A549 cells. AE (100-500 ${\mu}g/m{\ell}$) resulted in apoptosis via activation of caspase 9 following PARP cleavage in a time-and dose-dependent manner. The levels of Bax and Bad levels were increased by AE with a concomitant decrease of Bcl-xL. In addition, AE at the low dose (30 ${\mu}g/m{\ell}$) significantly inhibited cell growth in the presence of serum. Conclusion : AE has the potential as a therapeutic agent against lung cancer.

• 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.

• Archives of Pharmacal Research
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• v.22 no.5
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• pp.448-453
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• 1999

In ginsenoside Rh2-treated rat glioma C6Bu-1 cells, apoptotic morphological changes, such as cell shrinkage, chromatin condensation and pyknosis were confirmed by means of electron microscopy. To evaluate whether induction of apoptosis by ginsenoside Rh2 is mediated by the members of Bcl-2 family, we first established C6Bu-1 cells overexpressing Bcl-2. It was demonstrated that the expression of Bcl-2, Bcl-xL, and Bax was not altered in ginsenoside Rh2-treated C6Bu-1 overexpressing C6Bu-1 cells failed to prevent from ginsenoside Rh2-induced cell death. These results suggest the existence of other apoptotic pathway that requires induction of apoptosis by ginsenoside Rh2 rather than the pathway through Bcl-2, $Bcl-x_{L}$ or Bax in C6Bu-1 cells.

• Journal of Life Science
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• v.17 no.11
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• pp.1596-1600
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• 2007

Bee venom is used to treat inflammatory diseases in Korean traditional medicine and has been known to inhibit proliferation and induce apoptosis in cancer cells. However, the molecular mechanisms involved in bee venom-induced apoptosis are still uncharacterized in human lung cancer cells. In the present study, we investigated the effects of bee venom on the apoptosis of A549 human lung epithelial cancer cells. Treatment of bee venom inhibited the cell viability and induced apoptosis in a concentration-dependent manner as measured by hemocytometer counts, fluorescence microscopy and flow cytometry analysis. Bee venom-induced apoptosis in A549 cells was associated with a marked inhibition of anti-apoptotic Bcl-2 expression without significant changes in the levels of Bax and Bcl-xL. Bee venom treatment also inhibited the levels of IAP family members such as cIAP-1 and cIAP-2 and induced the proteolytic activation of caspase-3 and caspase-9. Although further studies are needed, the present results suggest that apoptotic signals evoked by bee vemon in A549 cancer cells may converge caspases activation through a down-regulation of Bcl-2 rather than an up-regulation of Bax. These findings provide important insights into the possible molecular mechanisms of the anti-cancer activity of bee vemon in human cancer cells.

• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.283-288
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• 2021

This study investigated the anticancer activity of methanol extract from Platycarya strobilacea leaf in AGS human gastric cancer cells. We determined the cell viability effect of P. strobilacea using MTS assay. Apoptosis induction and cell cycle arrest were confirmed by fluorescein isothiocyanate and propidium iodide staining using cellometer K2. The mRNA expression levels of the Bcl-2 family were confirmed by reverse transcription-polymerase chain reaction. The cell viability was decreased in a dose-dependent manner treated with different concentrations of P. strobilacea. Total, early, and late apoptotic cells were dramatically increased, and the cell cycle was arrested at the sub-G1 phase. The mRNA expressions of Bcl-2 and Bcl-xL were reduced, whereas pro-apoptotic factors, Bax and Bak, were increased in a dose-dependent manner. These results suggested that P. strobilacea leaf extract induced significant apoptotic activity through an intrinsic mitochondria pathway.

• Molecules and Cells
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• v.24 no.3
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• pp.378-387
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• 2007

The Bcl-2 family of proteins interacts at the mitochondria to regulate apoptosis. However, the anti-apoptotic Bcl-2 and $Bcl-X_L$ are not completely localized to the mitochondria. In an attempt to generate Bcl-2 and $Bcl-X_L$ chimeras that are constitutively localized to the mitochondria, we substituted their C-terminal transmembrane tail or both the C-terminal transmembrane tail and the adjacent loop with the equivalent regions from Bak or Bax mutant (BaxS184V) as these regions determine the mitochondrial localization of Bak and Bax. The effects of these substitutions on subcellular localization and their activities were assessed following expression in HeLa and CHO K1 cells. The substitution of the C-terminal tail or the C-terminal tail and the adjacent loop of Bcl-2 with the equivalent regions from Bak or the Bax mutant resulted in its association with the mitochondria. This change in subcellular localization of Bcl-2 chimeras triggered cells to undergo apoptotic-like cell death. The localization of this Bcl-2 chimera to the mitochondria may be associated with the disruption of mitochondrial membrane potential. Unlike Bcl-2, the loop structure adjacent to the C-terminal tail in $Bcl-X_L$ is crucial for its localization. To localize the $Bcl-X_L$ chimeras to the mitochondria, the loop structure next to the C-terminal tail in $Bcl-X_L$ protein must remain intact and cannot be substituted by the loop from Bax or Bak. The chimeric $Bcl-X_L$ with both its C-terminal tail and the loop structure replaced by the equivalent regions of Bak or Bax mutant localized throughout the entire cytosol. The $Bcl-X_L$ chimeras that are targeted to the mitochondria and the wild type $Bcl-X_L$ provided same protection against cell death under several death inducing conditions.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.5
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• pp.289-295
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• 2006

Sodium fluoride (NaF) has been shown to be cytotoxic and elicit inflammatory response in human. However, the cellular mechanisms underlying NaF-induced cytotoxicity in periodontal tissues have not yet been elucidated. This study is aimed to investigate the mechanisms of NaF-induced apoptosis in human gingival fibroblast (HGF). NaF decreased the cell viability of HGF in a dose- and time-dependent manner. NaF gave rise to apoptotic morphological changes including cell shrinkage, chromatin condensation, and DNA fragmentation. However, NaF did not affect the production of ROS. In addition, NaF augumented cytochrome c release from mitochondria into the cytosol, and enhanced caspase -9 and -3 activities., cleavage (85 kDa fragments) of poly (ADP-ribose) polymerase (PARP) and upregulation of voltage-dependent anion channel (VDAC) 1. These results demonstrated that NaF-induced apoptosis in HGF may be mediated with mitochondria. Furthermore, NaF elevated caspase-8 activity and upregulated Fas-ligand (Fas-L), suggesting involvement of death receptor mediated pathway in NaF-induced apoptosis. Expression of Bcl-2, an anti-apoptotic Bcl-2 family, was downregulated, whereas expression of Bax, a pro-apoptotic Bcl-2 family, was not affected in NaF-treated HGF. These results suggest that NaF induces apoptosis in HGF through both mitochondria- and death receptor-mediated pathway mediated by Bcl-2 family.