• BMB Reports
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• v.53 no.2
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• pp.112-117
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• 2020

A recent study suggested that methylation of ubiquitin-like with PHD and RING finger domain 1 (UHRF1) is regulated by SET7 and lysine-specific histone demethylase 1A (LSD1) and is essential for homologous recombination (HR). The study demonstrated that SET7-mediated methylation of UHRF1 promotes polyubiquitination of proliferating cell nuclear antigen (PCNA), inducing HR. However, studies on mediators that interact with and recruit UHRF1 to damaged lesions are needed to elucidate the mechanism of UHRF1 methylation-induced HR. Here, we identified that poly [ADP-ribose] polymerase 1 (PARP1) interacts with damage-induced methylated UHRF1 specifically and mediates UHRF1 to induce HR progression. Furthermore, cooperation of UHRF1-PARP1 is essential for cell viability, suggesting the importance of the interaction of UHRF1-PARP1 for damage tolerance in response to damage. Our data revealed that PARP1 mediates the HR mechanism, which is regulated by UHRF1 methylation. The data also indicated the significant role of PARP1 as a mediator of UHRF1 methylation-correlated HR pathway.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.947-952
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• 2008

The unripe fruit of Momordica charantia (MC) has been shown to possess antidiabetic activity. However, the mechanism of its antidiabetic action has not been fully understood. In this study, the effects of the aqueous ethanolic extract of MC (AEE-MC) were evaluated on the apoptosis in pancreatic $\beta$-cells treated with a combination of the cytokines, interleukin (IL)-$1{\beta}$, tumor necrosis factor (TNF)-$\alpha$, and interferon (IFN)-$\gamma$. In MIN6N8 cells, the inhibitory effect of AEE-MC was significantly observed at 2 to 50 ${\mu}g/mL$: a 26.2 to 55.6% decrease of cytoplasmic DNA fragments quantified by an immunoassay. The molecular mechanisms, by which AEE-MC inhibited $\beta$-cell apoptosis, appeared to involve the inhibition on the expression of p21, Bax, and Bad, the up-regulation of Bcl-2 and Bcl-$X_L$, and the inhibition on the cleavage of caspase-9, -7, and -3 and poly (ADP-ribose) polymerase. This study suggests that MC may inhibit cytokine-induced apoptosis in $\beta$-cells and, thus, may contribute via this action to the antidiabetic influence in diabetes.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.4
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• pp.1147-1152
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• 2004

To investigate the anti-cancer effects of aqueous extract of Cheonkumwikyung-tang (CKWKT) on the growth of human lung carcinoma cell line A549, we performed various biochemical experiments such as the effects of CKWKT on the cell proliferation and viability, the morphological changes, the effects on expression of apoptosis and cell growth-regulatory gene products. Results obtained are as follow; CKWKT treatment declined the cell viability and proliferation of A549 cells in a concentration-dependent manner. The anti-proliferative effect by CKWKT treatment in A549 cells was associated with morphological changes such as membrane shrinking and cell rounding up. CKWKT treatment induced apoptotic cell death of A549 cells in a concentration-dependent manner, which was associated with inhibition and/or degradation of apoptotic target proteins such poly(ADP-ribose) polymerase, β-catenin and phospholipase C-γ1. Western blot analysis revealed that the levels cyclin-dependent kinase inhibitor p21 expression were induced by CKWKT treatment in A549 cells. Taken together, these findings suggest that CKWKT-induced inhibition of human lung cancer cell proliferation is associated with the induction of apoptotic cell death via regulation of several major growth regulatory gene products and CKWKT may have therapeutic potential in human lung cancer.

• Toxicological Research
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• v.25 no.3
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• pp.113-118
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• 2009

Cell death induced by menadione (vitamin K-3,2-methyl-1,4-naphthoquinone) has been investigated in human promyelocytic leukemia HL-60 cells. Menadione was found to induce both apoptosis and necrosis in HL-60 cells. Low concentration ($1{\sim}$50 ${\mu}$M) of menadione induced apoptotic cell death, which was demonstrated by typical DNA ladder patterns on agarose gel electrophoresis and flow cytometry analysis. In contrast, a high concentration of menadione (100 ${\mu}$M) induced necrotic cell death, which was demonstrated by DNA smear pattern in agarose gel electrophoresis. Necrotic cell death was accompanied with a great reduction of cell viability. Menadione activated caspase-3, as evidenced by both increased protease activity and proteolytic cleavage of 116 kDa poly(ADP-ribose) polymerase (PARP) into 85 kDa cleavage product. Caspase-3 activity was maximum at 50 ${\mu}$M of menadione, and very low at 100 ${\mu}$M of menadione. Taken together, our results showed that menadione induced mixed types of cell death, apoptosis at low concentrations and necrosis at high concentrations in HL-60 cells.

• Herbal Formula Science
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• v.25 no.3
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• pp.349-362
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• 2017

Objectives : We investigated whether the components of Ailanthus altissima induced apoptotic cell death in Jurkat acute lymphoblastic leukemia (ALL) cells. Methods : Regulation of cell proliferation is a complex process involving the regulated expression and/or modification of discrete gene products, which control transition between different stages of the cell cycle. Results : Upon treatments with Ailanthus altissima, the concentration-dependent inhibitions of cell viability were observed as compared to untreated control group. The capability of Ailanthus altissima to induce apoptosis was associated with proteolytic cleavage of specific target proteins such as poly(ADP-ribose)polymerase (PARP) and beta-catenin proteins suggesting the possible involvement of caspases. Ailanthus altissima also caused apoptosis as measured by cell morphology and DNA fragmentation. Conclusions : These results indicate that the increase of apoptotic cell death by Ailanthus altissima may be due to the inhibition of cell cycle in human Jurkat lymphocytes. Conclusively, these current and further findings will provide novel approaches to understanding and treating major diseases.

• The Journal of Korean Medicine
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• v.26 no.2 s.62
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• pp.63-76
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• 2005

Objectives: Reactive oxygen species (ROS) have been implicated in the pathogenesis of a wide range of acute and longterm neurodegenerative diseases. This study was undertaken to examine whether Sunghyangchungisan(SHCS), a well-known prescription in Korean traditional medicine, might have beneficial effects on ROS-induced brain cell injury. Methods: Human neuroglioma cell line A172 and H2O2 were employed as an experimental model cell and oxidant. Results: SHCS effectively protected the cells against both the necrotic and apoptotic cell death induced by H2O2. The effect of SHCS was dose-dependent at concentrations ranging from 0.2 to 5mg/ml. SHCS significantly prevented depletion of cellular ATP and activation of poly (ADP-ribose) polymerase induced by H2O2. It also helped mitochondria to preserve its functional integrity estimated by MTT reduction ability. Furthermore, SHCS significantly prevented H202-induced release of cytochrome c into cytosol. Determination of intracellular ROS showed that SHCS might exert its role as a powerful scavenger of intracellular ROS. Conclusions: The present study provides clear evidence for the beneficial effect of SHCS on ROS-induced neuroglial cell injury. The action of SHCS as an ROS-scavenger might underlie the mechanism.

• Biomedical Science Letters
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• v.17 no.3
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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.

• BMB Reports
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• v.28 no.5
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• pp.392-397
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• 1995

The effect of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on the intracellular $Ca^{2+}$ level was studied in NIH3T3 fibroblast cells. A reduction of the intracellular $Ca^{2+}$ level was observed after exposure to 300 ${\mu}m$ MNNG. However, the intracellular level of $IP_3$, a well-known regulator of $Ca^{2+}$ release from internal storage, was not changed by MNNG treatment. Instead, a reduction of the intracellular NAD level was observed. NAD as well as $IP_3$ stimulated intracellular $Ca^{2+}$ release from permeabilized cells. The treatment of 3-aminobenzamide, which inhibited the MNNG-induced reduction of the NAD level, also prevented the MNNG-induced decrease of the $Ca^{2+}$ level. Our data suggest that MNNG reduces the intracellular $Ca^{2+}$ level by NAD depletion in NIH3T3 cells.

• Biomolecules & Therapeutics
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• v.12 no.2
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• pp.85-91
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• 2004

In all attempt to elucidate the role of apoptosis in drug resistance, cisplatin-resistant human chronic myelogenous leukemia (CML) K562 cells (K562/CDDP) were established and compared with drug sensitive parent cells (K562) in the induction of apoptosis. K562/CDDP cells were 5-fold more resistant to cisplatin compared to K562 cells. In addition, K562/CDDP cells were significantly more resistant to apoptois as judged by DNA fragmentation and DAPI staining. K562/CDDP cells exhibited decreased proleolytic activity of caspase-3 and this was further demonstrated by decreased cleavage of its substrate poly (ADP-ribose) polymerase (PARR- Western blot analysis showed that K562/CDDP cells had longer sustained levels of BCL-$X_L$ whereas no difference was noted in the level of Bcl-2. the translocation of Bax to mitochondria was significantly delayed in K562/CDDP cells. These results suggest that the reduced translocation of Bax and the sustained expression of BCL-$X_L$ may cause resistance to apoptosis through prevention of mitochondria release of cytochrome c, which subsequently induces reduction of caspase-3 activity and that this response is partly responsible for the acquired resistance to cisplatin ill K562 cells.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.4
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• pp.281-285
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• 2009

Rotenone, a mitochondrial complex I inhibitor, can induce the pathological features of Parkinson's disease (PD). In the present study, naringin, a grapefruit flavonoid, inhibited rotenone-induced cell death in human neuroblastoma SH-SY5Y cells. We assessed cell death and apoptosis by measuring mitogen-activated protein kinase (MAPKs) and caspase (CASPs) activities and by performing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Naringin also blocked rotenone-induced phosphorylation of Jun NH2-terminal protein kinase (JNK) and P38, and prevented changes in B-cell CLL/lymphoma 2 (BCL2) and BCL2-associated X protein (BAX) expression levels. In addition, naringin reduced the enzyme activity of caspase 3 and cleavages of caspase 9, poly (ADP-ribose) polymerase (PARP), and caspase 3. These results suggest that naringin has a neuroprotective effect on rotenone-induced cell death in human neuroblastoma SH-SY5Y cells.