• International Journal of Industrial Entomology and Biomaterials
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• 제27권2호
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• pp.228-236
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• 2013

Breast cancer is one of the most common cancers among women worldwide. Recently anticancer agents have been developed using natural substances. To evaluate the anticancer effect of hydrolysates of silk fibroin (HSF), we investigated the effect of HSF on cell viability and apoptosis of a breast cancer cell line, MCF-7, induced through the mitochondrial pathway. The result showed that HSF decreased cell viability in MCF-7 cells in a dose- and time-dependent manner, resulting in an increase in the sub-G1 phase cell population. HSF increased the level of the pro-apoptotic Bax protein and decreased the levels of the anti-apoptotic Bcl-2 protein. In addition, HSF induced apoptosis in MCF-7 cells through a mitochondria-dependent pathway by increasing levels of cytochtome c, and cleavage of PARP. Taken together, these findings suggest that HSF inhibits the proliferation of MCF-7 breast cancer cells through a mitochondria and caspase dependent apoptotic pathway.

• Molecular & Cellular Toxicology
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• 제4권2호
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• pp.144-149
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• 2008

Despite versatile activity (cancericidal, antimicrobial, hypoxia inducible factor (HIF) inhibition, immune deactivation of DNA bis-intercalation agent, echinomycin, its specific mechanism has been elusive. Of these novel mechanisms, we reported that using human colon cancer cells (HT-29), apoptotic machinery induced by echinomycin might be dependent of caspase-3 pathway. Despite a partial enlightenment of prototypic signal path triggered by echinomycin, the role of Bcl-2 in this signaling pathway is unclear. To address this issue, we explored whether or not echinomycin would overcome the anti-apoptotic impact of Bcl-2 in HT-29 cells by the controlled Bcl-2 overexpression. Prior to this proof, we confirmed that echinomycin induces mitochondrial depolarization, then triggering the mitochondrial pathway of apoptosis with an involvement of upstream cas-pases-3. Transiently transfection with inactive Bax-DNA failed to prevent echinomycin-induced apoptosis in HT-29 cells. To dissect the role of Bcl-2 in echinomycin-induced apoptosis, HT-29 cells were transiently transfected with Bcl-2 DNA for overexpression and then treated with echinomycin for 24h. Combined analyses of DNA fragmentation and flow cytometric analysis clearly verified that echinomycin-induced apoptosis was drastically attenuated by Bcl-2 overexpression, whereas a control vector rarely affected echinomycin-induced apoptosis. Collectively, these data verify that Bcl-2 regulates echinomycin-induced apoptosis in HT-29 cells. To my knowledge, this is the first evidence that of diverse, structured minor groove binders (MGB), the prototypic echinomycin might control the apoptotic signaling via Bcl-2-mitochondrial pathway.

• The Korean Journal of Physiology and Pharmacology
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• 제24권3호
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• pp.259-266
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• 2020

Cardiovascular diseases are the primary reason of mortality, among which myocardial infarction (MI) is the most dominant and prevalent. This study was considered to examine D-Limonene protective action against isoproterenol (ISO) induced MI. Wister male rats were dispersed into four groups. Normal and D-Limonene control group in which rats administered saline or D-Limonene. ISO control animals were administered saline for 21 days then challenged with ISO (85 mg/kg, subcutaneously) on 20th and 21st day for MI induction. D-Limonene pretreated group in which animals were pretreated with D-Limonene 50 mg/kg orally for 21 days then administered ISO on 20th and 21st day. MI prompted variations were assessed by myocardial infarction area determination, blood pressure (BP) alterations, cardiac injury biomarkers and inflammatory mediators measurements. For more depth investigation, both the apoptotic status was evaluated via measuring mRNA expression of Bcl-2 and Bax as well as mitogen-activated protein kinase-extracellular signal-regulated kinase (MAPK-ERK) signal transduction were investigated via Western blotting. MI group revealed significant infarcted area, blood pressure alterations, myocardial injury enzymes intensification together with inflammatory cytokines amplification. MI was associated with activation of MAPK-ERK signal pathway and apoptotic status within the myocardium. On the other hand, pretreated with D-Limonene demonstrated deterred infracted area, reduced myocardial enzymes, improved BP indices, lessened inflammatory levels. Furthermore, D-Limonene pretreatment caused a decline in MAPK proteins pathway and Bax relative mRNA expression, while intensifying Bcl-2 mRNA expression promoting that D-Limonene may constrain MI induced myocardial apoptosis. D-Limonene mitigated MI injury through MAPK/NF-κB pathway inhibition and anti-apoptotic effect.

• BMB Reports
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• 제55권6호
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• pp.299-304
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• 2022

Chloride channel-5 (ClC-5), an important branch of the ClC family, is involved in the regulation of the proliferation and cell-fate of a variety of cells, including tumor cells. However, its function in cholangiocarcinoma (CCA) cells remains enigmatic. Here, we discovered that ClC-5 was up-regulated in CCA tissues and CCA cell lines, while ClC-5 silencing inhibited CCA cell proliferation and induced apoptosis. Further mechanism studies revealed that ClC-5 inhibition could inhibit Wnt/β-catenin signaling activity and further activate the mitochondria apoptotic pathway in CCA cells. Furthermore, rescuing Wnt/β-catenin signaling activation eliminated the anti-tumor function of ClC-5 knockdown. Together, our research findings illustrated that ClC-5 inhibition plays an anti-tumor role in CCA cells via inhibiting the activity of the Wnt/β-catenin pathway, which in turn activates the mitochondrial apoptotic pathway.

• Animal cells and systems
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• 제9권3호
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• pp.173-179
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• 2005

Cyclic-AMP-dependent protein kinase (PKA) seems to function as a negative regulator of the c-Jun $NH_2-terminal$ kinase (JNK) signaling pathway. We demonstrate here that the activity of the PKA catalytic subunit (PKAc) is reduced in apoptotic PC12 pheochromocytoma cells. Apoptotic progress was inhibited by dibutyryl cyclic AMP (dbcAMP), an analog of cAMP. The rescue by dbcAMP was attributable to inhibition of the JNK but not of the p38 signaling pathway, due to the induction of PKA activity. JNK was present in immunocomplexes of PKAc, and PKAc phosphorylated JNK in vitro. Presence of p38 kinase, however, was not prominent in immunocomplexes of PKAc. Our data suggest that JNK is a target point of negative regulation by PKAc in the JNK signaling pathway.

• 한국식품영양과학회지
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• 제45권12호
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• pp.1708-1716
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• 2016

Akt 및 mTOR는 세포 생존에 필수적인 경로로 세포 성장과 증식 등에서 중요한 역할을 하는 것으로 알려져 있다. 본 연구에서는 항암 및 항균 효과가 있는 것으로 알려진 개똥쑥(Artemisia annua L.)에 의한 HepG2 간암세포의 apoptosis 유도 효과를 확인하였다. 본 연구 결과에 의하면 개똥쑥 추출물의 처리 농도가 증가함에 따라 HepG2 세포의 생존율은 억제되었으며, 이는 apoptosis 유도 효과에 의한 것임을 세포의 형태적 변화와 flow cytometry를 통해 확인하였다. 그리고 mitopotential assay와 caspase-3/7 activity assay, western blotting으로 Bcl-2 family 단백질을 확인함으로써 apoptosis 경로 중 내인성 경로(intrinsic pathway)에 의해 apoptosis가 일어남을 알 수 있었다. 이러한 효과는 Akt/mTOR의 활성 저해와 연관이 있었으며 Akt/mTOR의 저해제인 LY294002/rapamycin을 개똥쑥 추출물과 병행처리하였을 경우 개똥쑥 추출물에 의한 apoptosis 효과를 더욱 증대시켰다. 따라서 Akt/mTOR의 저해는 개똥쑥 추출물의 apoptosis 효과를 상승시켰으며 이에 따라 미토콘드리아의 기능 손상과 caspase 활성의 증가를 통해 이루어짐을 확인하였다.

• Biomolecules & Therapeutics
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• 제17권1호
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• pp.17-24
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• 2009

Histone deacetylase (HDAC) inhibitors are a promising class of anticancer agents that inhibit cancer cell growth in vitro and in vivo. Previous report has shown that apicidin inhibited SK-OV-3 cells proliferation and down-regulation of cyclin B1 and CDK1, and up-regulation of $p21^{WAF1}$ and p27. However, the mechanism of apicidin-mediated apoptotic cell death is not clearly understood. For this study, we investigated the mechanism of apoptotic pathway induced by apicidin in human ovarian cancer cell. We found that SK-OV-3 cells treated with apicidin caused an increase in the percentage of cells in the G2/M phase, which preceded apoptosis characterized by the appearance of cells with sub-G1 population. To further investigate the mechanism of apoptosis induction by apicidin, we measured TUNEL assay, poly-ADP ribose polymerase (PARP) cleavage, and caspase activity in SK-OV-3 cells treated with apicidin for 48 h. Apicidin significantly enhanced apoptosis as measured by TUNEL positive apoptotic cells, PARP cleavage, and increased Bax/Bcl-2 ratio. Induction of apoptosis was confirmed by the release of cytochrome c to cytosol. Our data suggest that apicidin-induced apoptosis in SK-OV-3 cells was accompanied by caspase-3 activation and the increase in Bax/Bcl-2 ratio. These data suggest that apicidin may be effective in the treatment of ovarian cancer through activation of intrinsic apoptotic pathway.

• 대한의생명과학회지
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• 제17권3호
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• pp.177-184
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• 2011

Potassium cyanate (KOCN) is an inorganic compound and induces the carbamylation of proteins with cytotoxic effects on human cells. Although there is a potential cytotoxic molecule, the role of KOCN on the apoptosis of cancer cell is not well understood. The present study investigated the effects of KOCN on the human colorectal cancer cell line, HCT 116 cells. To understand the anti-cancer effect of KOCN on HCT 116 cells, we examined alteration of apoptosis, the intracellular $Ca^{2+}$ concentration, the intracellular signaling pathway and generation of reactive oxygen species (ROS) in these cells treated with KOCN. The apoptosis of HCT 116 cells was induced by KOCN in a dose-dependent manner at 24 hours and 48 hours, respectively. The apoptosis was processed via the cleavage of poly ADP-ribose polymerase (PARP) and activation of caspase 3 in HCT 116 cells. KOCN induced the elevation of intracellular $Ca^{2+}$ concentration and changed the expressions of Bcl-2 family proteins. The pro-apoptotic Bax was continuously up-regulated, and the anti-apoptotic Bcl-2 was down-regulated by KOCN. KOCN also induced the hyperpolarization of mitochondria and the generation of ROS in HCT 116 cells. Taken together, these results indicate that KOCN induces the apoptosis of HCT 116 cells by disruption of $Ca^{2+}$ homeostasis and via mitochondrial pathway. This study provides the compound that may be used as a potent agent for the treatment of colorectal cancer.

• 한국결정학회:학술대회논문집
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• 한국결정학회 2004년도 학술대회지
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• pp.12-12
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• 2004

• Biomolecules & Therapeutics
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• 제22권3호
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• pp.184-192
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• 2014

${\beta}$-lapachone is a naturally occurring quinone that selectively induces apoptotic cell death in a variety of human cancer cells in vitro and in vivo; however, its mechanism of action needs to be further elaborated. In this study, we investigated the effects of ${\beta}$-lapachone on the induction of apoptosis in human gastric carcinoma AGS cells. ${\beta}$-lapachone significantly inhibited cellular proliferation, and some typical apoptotic characteristics such as chromatin condensation and an increase in the population of sub-G1 hypodiploid cells were observed in ${\beta}$-lapachone-treated AGS cells. Treatment with ${\beta}$-lapachone caused mitochondrial transmembrane potential dissipation, stimulated the mitochondria-mediated intrinsic apoptotic pathway, as indicated by caspase-9 activation, cytochrome c release, Bcl-2 downregulation and Bax upregulation, as well as death receptor-mediated extrinsic apoptotic pathway, as indicated by activation of caspase-8 and truncation of Bid. This process was accompanied by activation of caspase-3 and concomitant with cleavage of poly(ADP-ribose) polymerase. The general caspase inhibitor, z-VAD-fmk, significantly abolished ${\beta}$-lapachone-induced cell death and inhibited growth. Further analysis demonstrated that the induction of apoptosis by ${\beta}$-lapachone was accompanied by inactivation of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. The PI3K inhibitor LY29004 significantly increased ${\beta}$-lapachone-induced apoptosis and growth inhibition. Taken together, these findings indicate that the apoptotic activity of ${\beta}$-lapachone is probably regulated by a caspase-dependent cascade through activation of both intrinsic and extrinsic signaling pathways, and that inhibition of the PI3K/Akt signaling may contribute to ${\beta}$-lapachone-mediated AGS cell growth inhibition and apoptosis induction.