• Animal cells and systems
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• 제9권4호
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• pp.181-190
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• 2005

BIRPs (BIR containing Proteins) which contain one to three BIR domains constitute a highly conserved family from yeast to human. BIR domains mediate the interaction of BIRPs with various other proteins. Some of the members acquire a Ring domain which acts as an E3 ubiquitin ligase. The first member of BIRPs identified in the baculovirus was found as an inhibitor of apoptosis and most of the family members in the other species have been recognized to have the same function which bind to and inhibit caspases, thereby suppresses apoptotic cell death. But an increasing number of evidences indicate that BIRPs are involved in various cellular events such as cell division, control of cell cycle, signal transduction, cell migration, innate immunity as well as regulation of apoptosis. In this review, we summarize the structural and functional features of the BIRPs, especially focus on the various functions of BIRPs unrelated to regulation of apoptosis by the recent findings.

• International Journal of Oral Biology
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• 제49권2호
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• pp.42-47
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• 2024

Ophiopogonin D (OPD) is a steroidal glycoside derived from Ophiopogon japonicus, a traditional Chinese medicine with diverse biological activities, including antithrombosis, anti-inflammation, and antitussive effects. To investigate the cellular effects and mechanisms of OPD on oral squamous cell carcinoma, cell viability was explored, and the effects of OPD on cell cycle regulators, apoptotic marker proteins, and key proteins involved in metastasis and signaling pathways were examined by MTT assay and Western blotting in YD38 cells. OPD strongly inhibited cell proliferation and induced caspase-dependent apoptosis of YD38 cells by suppressing the cell cycle and activating caspase-3 and poly ADP ribose polymerase. Additionally, OPD suppressed the expression of vital proteins regulating metastasis and proliferation within the integrin/matrix metalloproteinases/FAK and AKT/PI3K/mTor pathways. Thus, OPD can be a potential treatment candidate for gingival cancer.

• International Journal of Oral Biology
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• 제45권3호
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• pp.107-114
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• 2020

Acacetin, which is present in damiana (Turnera diffusa) and black locust (Robinia pseudoacacia), has several pharmacologic activities such as antioxidant, anti-inflammatory, and anti-proliferative effects on cancer cells. However, the effect of acacetin on head and neck cancers has not been clearly established. This study aimed to examine the effects of acacetin on cell growth and apoptosis induction in FaDu human pharyngeal carcinoma cells. These were investigated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, Live/Dead cell assay, 4',6-diamidino-2-phenylindole dihydrochloride staining, caspase-3 and caspase-7 activation assay, and immunoblotting in FaDu cells. Acacetin induced FaDu cell death in a dose-dependent manner, with an estimated IC₅₀ value of 41.9 µM, without affecting the viability of L-929 mouse fibroblasts as normal cells. Acacetin treatment resulted in nuclear condensation in the FaDu cells. It promoted the proteolytic cleavage of procaspase-3, -7, -8, and -9 with increasing amounts of the cleaved caspase isoforms in FaDu cells. Acacetin-induced apoptosis in FaDu cells was mediated by the expression of Fas and activation of caspase-8, caspase-3, and poly (ADP-ribose) polymerase. Immunoblotting showed downregulation of the anti-apoptotic mitochondrial proteins Bcl-2 and Bcl-xL, but upregulation of the mitochondria-dependent pro-apoptotic proteins Bax and Badin FaDu cells after acacetin treatment. These findings indicate that acacetin inhibits cell proliferation and induces apoptotic cell death in FaDu human pharyngeal carcinoma cells via both the death receptor-mediated extrinsic apoptotic pathway and the mitochondria-mediated intrinsic apoptotic pathway.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 춘계학술대회
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• pp.111-111
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• 2019

Glycyrrhizae radix is one of the most frequently prescribed ingredients in Oriental medicine, and G. radix extract has been shown to exert anti-cancer effects. However, the cellular and molecular mechanisms of apoptosis by G. radix are poorly defined. In the present study, it was examined the biochemical mechanisms of apoptosis by water extract of G. radix (WEGR) in human bladder T24 cancer cells. It was found that WEGR could inhibit the cell growth of T24 cells in a dose-dependent manner, which was associated with the induction of apoptotic cell death, as evidenced by the formation of apoptotic bodies, DNA fragmentation and increased populations of annexin-V positive cells. The induction of apoptotic cell death by WEGR was connected with an up-regulation of pro-apoptotic Bax protein expression and down-regulation of anti-apoptotic Bcl-2 and Bcl-xL proteins, and inhibition of apoptosis family proteins (XIAP, cIAP-1 and cIAP-2). In addition, apoptosis-inducing concentrations of WEGR induced the activation of caspase-9, an initiator caspase of the mitochondrial-mediated intrinsic pathway, and caspase-3, accompanied by proteolytic degradation of poly (ADP-ribose)-polymerase. WEGR also induced apoptosis via a death receptor-mediated extrinsic pathway by caspase-8 activation, resulting in the down-regulation of total Bid and suggesting the existence of cross-talk between the extrinsic and intrinsic pathways. Taken together, the present results suggest that WEGR may be a potential chemotherapeutic agent for the control of human bladder cancer cells.

• Animal cells and systems
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• 제5권4호
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• pp.267-274
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• 2001

Calpains are a family of cysteine proteases existing primarily in two forms designated by the $Ca^{2+}$ concentration needed for activation in vitro, $\mu$-calpain (calpain-I) and m-calpain (calpain-II). The physiologica1 roles of calpains remain unclear. Many groups have proposed a role for calpains In apoptosis, but their patterns of activation are not well characterized. Calpains have been implicated in neutrophil apoptosis, glucocorticoid-induced thymocyte apoptosis, as well as many other apoptotic pathways. Calpain activation in apoptosis is usually linked upstream or downstream to caspase activation, or in a parallel pathway alongside caspase activation. Calpains have been suggested to be involved in DNA fragmentation (via endonuclease activation), but also as effector proteases that cleave cellular proteins involved in DNA repair, membrane associated proteins and other homeostatic regulatory proteins. Recently, our laboratory demonstrated $\mu$-calpain activation in NAD(P)H: quinone oxidoreducatse 1 (NQO1)-expressing cells after exposure to $\beta$-lapachone, a novel quinone and potential chemo- and radio-therapeutic agent. Increased cytosolic $Ca^{2+}$ in NQO1-expressing cells after $\beta$-lapachone exposures were shown to lead to $\mu$-calpain activation. In turn, $\mu$-calpain activation was important for substrate proteolysis and DNA fragmentation associated with apoptosis. Upon activation, $\mu$-calpain translocated to the nucleus where it could proteolytically cleave PARP and p53. We provided evidence that $\beta$-lapachone-induced, $\mu$-calpain stimulated, apoptosis did not involve any of the known caspases; known apoptotic caspases were not activated after $\beta$-lapachone treatment of NQO1-expressing cells, nor did caspase inhibitors have any effect on $\beta$-1apachone-induced cell death. Elucidation of processes by which $\beta$-1apachone-stimulated $\mu$-calpain activation and calpains ability to activate endonucleases and induce apoptosis independent of caspase activity will be needed to further develop/modulate $\beta$-lapachone for treatment of human cancers that over-express NQO1.

• Asian Pacific Journal of Cancer Prevention
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• 제17권2호
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• pp.581-590
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• 2016

Resistance to anoikis, a cell-detachment induced apoptosis, is one of the malignant phenotypes which support tumor metastasis. Molecular mechanisms underlying the establishment of this phenotype require further investigation. This study aimed at exploring protein expression profiles associated with anoikis resistance of a metastatic breast cancer cell. Cell survival of suspension cultures of non-metastatic MCF-7 and metastatic MDA-MB-231 cells were compared with their adherent cultures. Trypan blue exclusion assays demonstrated a significantly higher percentage of viable cells in MDA-MB-231 than MCF-7 cell cultures, consistent with analysis of annexin V-7-AAD stained cells indicating that MDA-MB-231 possess anti-apoptotic ability 1.7 fold higher than MCF-7 cells. GeLC-MS/MS analysis of protein lysates of MDA-MB-231 and MCF-7 cells grown under both culture conditions identified 925 proteins which are differentially expressed, 54 of which were expressed only in suspended and adherent MDA-MB-231 but not in MCF-7 cells. These proteins have been implicated in various cellular processes, including DNA replication and repair, transcription, translation, protein modification, cytoskeleton, transport and cell signaling. Analysis based on the STITCH database predicted the interaction of phospholipases, PLC and PLD, and 14-3-3 beta/alpha, YWHAB, with the intrinsic and extrinsic apoptotic signaling network, suggesting putative roles in controlling anti-anoikis ability. MDA-MB-231 cells grown in the presence of inhibitors of phospholipase C, U73122, and phospholipase D, FIPI, demonstrated reduced ability to survive in suspension culture, indicating functional roles of PLC and PLD in the process of anti-anoikis. Our study identified intracellular mediators potentially associated with establishment of anoikis resistance of metastatic cells. These proteins require further clarification as prognostic and therapeutic targets for advanced breast cancer.

• International Journal of Oral Biology
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• 제39권1호
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• pp.23-33
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• 2014

Several studies have shown that curcumin, which is derived from the rhizomes of turmeric, possesses antimicrobial, antioxidant and anti-inflammatory properties. The antitumor properties of curcumin have also now been demonstrated more recently in different cancers. This study was undertaken to investigate the modulation of cell cycle-related proteins and the mechanisms underlying apoptosis induction by curcumin in the SCC25 human tongue squamous cell carcinoma cell line. Curcumin treatment of the SCC25 cells resulted in a time- and dose-dependent reduction in cell viability and cell growth, and onset of apoptotic cell death. The curcumin-treated SCC25 cells showed several types of apoptotic manifestations, such as nuclear condensation, DNA fragmentation, reduced MMP and proteasome activity, and a decreased DNA content. In addition, the treated SCC25 cells showed a release of cytochrome c into the cytosol, translocation of AIF and DFF40/CAD into the nuclei, a significant shift in the Bax/Bcl-2 ratio, and the activation of caspase-9, caspase-7, caspase-6, caspase-3, PARP, lamin A/C, and DFF45/ICAD. Furthermore, curcumin exposure resulted in a downregulation of G1 cell cycle-related proteins and upregulation of $p27^{KIP1}$. Taken together, our findings demonstrate that curcumin strongly inhibits cell proliferation by modulating the expression of G1 cell cycle-related proteins and inducing apoptosis via proteasomal, mitochondrial, and caspase cascades in SCC25 cells.

• BMB Reports
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• 제46권12호
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• pp.588-593
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• 2013

Apoptosis, programmed cell death, is a process involved in the development and maintenance of cell homeostasis in multicellular organisms. It is typically accompanied by the activation of a class of cysteine proteases called caspases. Apoptotic caspases are classified into the initiator caspases and the executioner caspases, according to the stage of their action in apoptotic processes. Although caspase-3, a typical executioner caspase, has been studied for its mechanism and substrates, little is known of caspase-6, one of the executioner caspases. To understand the biological functions of caspase-6, we performed proteomics analyses, to seek for novel caspase-6 substrates, using recombinant caspase-6 and HepG2 extract. Consequently, 34 different candidate proteins were identified, through 2-dimensional electrophoresis/MALDI-TOF analyses. Of these identified proteins, 8 proteins were validated with in vitro and in vivo cleavage assay. Herein, we report that HAUSP, Kinesin5B, GEP100, SDCCAG3 and PARD3 are novel substrates for caspase-6 during apoptosis.

• 미생물학회지
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• 제38권3호
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• pp.213-220
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• 2002

일본뇌염바이러스(Japanese encephalitis virus, JEV)의 구조단백질 capsid (C), precursor membrane (prM/M), 및 envelop (E) 단백질의 독립적인 발현을 위한 inducible expression system을 구축하였다. 발현세포주로는 BHK-21을 사용하였으며 발현의 induction에는 tetracycline analog인 doxycycline이 사용되었다. Transfectant BHK-21/IV(vector대조구), BHK21/IC(C), BHK-21/IP (prM/M),및 BHK-21/IE는 G418과 hygromycin 존재하에 클로닝되었으며 doxycycline induction에 따른 각 유전자의 mRNA 전사를 확인하였다. 세포의 성장곡선, chromatin condensation, internucleosomal DNA fragmentation, 및 flow cytometry에 의한 DNA content profile 분석을 통해 induction에 의한 각 구조단백질의 발현이 숙주세포에 미치는 영향을 조사하였다. 세 transfectants 모두 세포성장이 감소하고 chromatin이 응축되었다. 그러나 DNA fragmentation 및 DNA content profile 분석에서는BHK-21/IC만이 induction에 따라 상응하여 반응하였다. 이상의 결과는 JEV 감염에 의한 apoptotic 세포사멸 유도기전에서 capsid 단백질이 직접적이고 독립적인 영향요인이 될 수 있음을 제시한다.

• 동의생리병리학회지
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• 제20권6호
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• pp.1548-1555
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• 2006

Bujeonghangam-tang(BHT) has been used as an anticancer agent in oriental medicine, but the mechanism by which it induces cell death in cancer cells is still unclear. To investigate cell death mechanism by BHT in cancer cells, the activities of apoptosis signaling pathway were tested in human neuroblastoma cell line LAN5. Viability of LAN5 cells was markedly decreased by treatment of the water extract of BHT in a dose-dependent manner. BHT induced cell death was confirmed as apoptosis characterized by chromatin condensation. We tested whether the water extract of BHT affects the anti-apoptotic protein such as Bcl-2 and Bcl-XL, and the pro-apoptotic protein such as Bax. Both Bcl-2 and Bcl-XL were gradually decreased but Bas was increased in a time-dependent manner after the addition of the water extract of BHT. Cleavage of Bid by activation of caspase-8 protease was also observed in LAN-5 cells by the treatment of the water extract of BHT. Taken together, these results suggest that the water extract of BHT exerts anti-cancer effects on human neuroblastoma LAN-5 cells by inducing the apoptotic death via down-regulation of anti-apoptotic proteins such as Bcl-2 and Bcl-XL, up-regulation of pro-apoptotic protein such as Bax, and activation of intrinsic caspase cascades.