• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3803-3807
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• 2012

Prohibitin (PHB), an evolutionarily-conserved protein, has been found to be over-expressed in gastric cancer and be closely related with tumor malignancy. In this study, to investigate the relationship between PHB expression and cell apoptosis in the BGC823 gastric cancer cell line, low and high expression PHB in BGC823 cells was accomplished using RNA interference technology and gene transfer techniques. Cell proliferation, cell cycling, apoptosis, Bax, Bcl-2 and Cyt.c protein expression and the activation of Caspase-3,9 were assessed after 48h. Over-expression of PHB gene in BGC823 cells resulted in slow cell growth, cell arrest in G2 phase, and an increased apoptosis ratio while the opposite was found for PHB under-expressing cells. In PHB over-expressing cells, the expression of Bax gene was increased, the expression of Bcl-2 was decreased, the activation level of Caspase-3, 9 was increased, but the activation level of Caspase-8 demonstrated no change. These results indicate that PHB induced apoptosis through the mitochondrial pathway.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.2
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• pp.195-201
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• 2015

The aim of the study is to investigate the anti-cancer effects of Scutellaria barbata in AGS human gastric adenocarcinoma cells. MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) assay and caspase 3 or 9 activity assay were carried out to examine cell death with Scutellaria barbata. To elucidate the inhibitory effects of Scutellaria barbata, cell cycle (sub-G1) analysis and mitochondrial membrane potential were performed in AGS cells after 24 h incubation with Scutellaria barbata. Scutellaria barbata induced apoptosis in AGS cells by using the MTT assay, the sub-G1 analysis and mitochondrial membrane potential assay. The stronger inhibition effects of AGS cell growth was observed by application of Scutellaria barbata combined with several anti-cancer drugs (paclitaxel, 5-fluorouracil, cisplatin, ectoposide, doxorubicin and docetaxel) in comparison to the application of Scutellaria barbata or anti-cancer drugs. Our findings provide insight into unraveling the effects of Scutellaria barbata in human gastric cancer cells and developing therapeutic agents against gastric cancer.

• Molecules and Cells
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• v.28 no.6
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• pp.521-527
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• 2009

Previously, we have reported tissue- and stage-specific expression of miR-372 in human embryonic stem cells and so far, not many reports speculate the function of this microRNA (miRNA). In this study, we screened various human cancer cell lines including gastric cancer cell lines and found first time that miR-372 is expressed only in AGS human gastric adenocarcinoma cell line. Inhibition of miR-372 using antisense miR-372 oligonucleotide (AS-miR-372) suppressed proliferation, arrested the cell cycle at G2/M phase, and increased apoptosis of AGS cells. Furthermore, AS-miR-372 treatment increased expression of LATS2, while over-expression of miR-372 decreased luciferase reporter activity driven by the 3' untranslated region (3' UTR) of LATS2 mRNA. Over-expression of LATS2 induced changes in AGS cells similar to those in AGS cells treated with AS-miR-372. Taken together, these findings demonstrate an oncogenic role for miR-372 in controlling cell growth, cell cycle, and apoptosis through down-regulation of a tumor suppressor gene, LATS2.

• The Journal of Korean Medicine
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• v.25 no.4
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• pp.79-89
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• 2004

Saussurea lappa and Taraxacum mongolicum have been used for herbal medicinal treatments against cancers in East Asia. We performed this study to understand the molecular basis underlying the anti-tumor effects of two herbs and analyzed the effects of these medicinal herbs on proliferation and on expression of cell growth/apoptosis related molecules by using an AGS gastric cancer cell line. The treatments of Saussurea lappa dramatically reduced cell viabilities in a dose and time-dependent manner, but Taraxacum mongolicum did not. FACS analysis and Annexin V staining assay also showed that Saussurea lappa induces apoptotic cell death of AGS. Expression analyses via RT-PCR and Western blots revealed that Saussurea lappa increased expression of the p53 and its downstream effector p21/sup Waf1/, and that the both increased expression of apoptosis related Bax and cleavage of active caspase-3 protein. We also confirmed the translocation of Bax to mitochondria Collectively, our data demonstrate that Saussurea lappa induces growth inhibition and apoptosis of human gastric cancer cells, and these effects are correlated with down- and up-regulation of growth-regulating apoptotic and tumor suppressor genes, respectively.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2379-2383
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• 2012

Objective: To investigate possible signal pathway involvement in multi-drug resistant P-glycoprotein (P-gp) expression induced by cyclooxygenase-2 (COX-2) in a human gastric adenocarcinoma cell line stimulated with pacliaxel (TAX). Methods: The effects of TAX on SGC7901 cell growth with different doses was assessed by MTT assay, along with the effects of the COX-2 selective inhibitor NS-398 and the nuclear factor-KB (NF-KB) pathway inhibitor pyrrolidine dithiocarbamate (PDTC). Influence on COX-2, NF-KB p65 and P-gp expression was determined by Western blotting. Results: TAX, NS-398 and PDTC all reduced SGC7901 growth, with dosedependence. With increasing dose of TAX, the expression of COX-2, p65 and P-gp showed rising trends, this being reversed by NS-398. PDTC also caused decrease in expression of p65 and P-gp over time. Conclusion: COX-2 may induce the expression of P-gp in SGC7901 cell line via the NF-kappa B pathway with pacliaxel stimulation.

• BMB Reports
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• v.51 no.12
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• pp.660-665
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• 2018

Human epidermal growth factor receptor 2 (HER2) inhibitors, such as trastuzumab and lapatinib are used to treat HER2-positive breast and gastric cancers. However, as with other targeted therapies, intrinsic or acquired resistance to HER2 inhibitors presents unresolved therapeutic problems for HER2-positive gastric cancer. The present study describes investigations with AUY922, a heat shock protein 90 (HSP90) inhibitor, in primary lapatinib-resistant (ESO26 and OE33) and lapatinib-sensitive gastric cancer cells (OE19, N87, and SNU-216) harboring HER2 amplification/over-expression. In order to investigate whether AUY922 could overcome intrinsic and acquired resistance to HER2 inhibitors in HER2-positive gastric cancer, we generated lapatinib-resistant gastric cancer cell lines (OE19/LR and N87/LR) by continuous exposure to lapatinib in vitro. We found that activation of HER2 and protein kinase B (AKT) were key factors in inducing intrinsic and acquired lapatinib-resistant gastric cancer cell lines, and that AUY922 effectively suppressed activation of both HER2 and AKT in acquired lapatinib-resistant gastric cancer cell lines. In conclusion, AUY922 showed a synergistic anti-cancer effect with lapatinib and sensitized gastric cancer cells with intrinsic resistance to lapatinib. Dual inhibition of the HSP90 and HER2 signaling pathways could represent a potent therapeutic strategy to treat HER2-positive gastric cancer with intrinsic and acquired resistance to lapatinib.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.3
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• pp.819-825
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• 2003

pharbitis nil and Taraxacum mongolicum are representative herbs that have been used for cancer treatment in Korean traditional medicine. To understand the molecular basis of the antitumor function, we analyzed the effect of these herbs on proliferation and apoptosis of tumor cells using a gastric cancer cell line AGS. Cell counting assay showed that pharbitis nil strongly inhibit cell proliferation Of AGS whereas Taraxacum mongolicum exhibit no detectable effect on cellular growth. [³H]thymidine uptake analysis also demonstrated that DNA replication of AGS is suppressed in a dose-dependent manner by treatment with pharbitis nil. Additionally, tryphan blue exclusion assay showed that Pharbitis nil induce apoptotic cell death of AGS in a dose-dependent. To explore whether anti antiproliferative and/or proapototic property of Pharbitis nil is associated with their effect on gene expression, we performed RT-PCR analysis of cell cycle- and apoptosis-related genes. Interestingly, mRNA expression levels of c-Jun, c-Fos, c-Myc, and Cyclin D1 were markedly reduced by Pharbitis nil. Taraxacum mongolicum also showed inhibitory action on expression of these growth-promoting protooncogene but there effects are less significant, as compared to Pharbitis nil. Furthermore, it was also found that Pharbitis nil activates expression of the p53 tumor suppressor and its downstream effector p21Waf1, which induce G1 cell cycle arrest and apoptosis. Collectively, our data demonstrate that Pharbitis nil induce growth inhibition and apoptosis of human gastric cancer cells and these effects are accompanied with down-and up-regulation of growth-regulating protooncogenes and tumor suppressor genes, respectively. This observation thus suggests that the anticancer effect of Pharbitis nil might be associated with its regulatory capability of tumor-related gene expression.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3887-3891
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• 2015

Aloe-emodin (1, 8-dihydroxy-3-hydroxyl-methylanthraquinone; AE) and emodin (1,3,8-trihydroxy-6-methylanthraquinone; EM) are anthraquinone derivatives that have been detected in some medical plants and share similar anthraquinone structures. AE and EM have been shown to exhibit anticancer activities in various cancer cell lines; however, the inhibitory effects of these derivatives on the growth of cancer cells were previously reported to be different. Gastric cancer is the second most common cause of cancer cell death worldwide. In the present study, we examined the inhibitory effects of 0.05 mM AE and 0.05 mM EM on the proliferation of the MKN45 human gastric cancer cell line. The proliferation of MKN45 cells was significantly inhibited in AE- and EM-treated groups 24 h and 48 h after treatment. Furthermore, the inhibitory effects of EM were stronger than those of AE. The cell cycle of MKN45 cells were arrested in G0/G1 phase or G0/G1 and G2/M phases by AE and EM, respectively. However, an analysis of intracellular polyamine levels and DNA fragmentation revealed that the mechanisms underlying cell death following cell arrest induced by AE and EM differed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.2
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• pp.340-347
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• 1994

The specimens used in this study were obtained from patients with primary gastric carcinoma and adjacent non-malignant mucosa from the same patients. Using the techniques of immunocyto chemicstry and in situ hybridization, transforming growth $factor-{\alpha}(TGF-{\alpha})$ and epiderimal growth factor receptor (EGF-R) nRNAs were identified. $TGF-{\alpha}$ was observed in macrophages and dividing tumor cells but, not in normal cells. EGF-R was observed both in malignant and non-malignant gastric tissues. Although normally, $TGF-{\alpha}$ is not seen in normal gastric tissues, $TGF-{\alpha}$ was discovered in the adjacent non-malignant tissue of histolgically normal, which strongly suggest that $TGF-{\alpha}$ is involved in the differentiation of cancer cells. Immunocytochemicstry using EMB-11 antibody identified the existence of macrophages which express $TGF-{\alpha}$ and EGF-R mRNA. Protein products of EGF-R was identfified using monoclonal antibody. Cancer cells were also identified in the non-malignant normal tissues by the method of immunocytochemicstry using carcino embryonic antigen (CEA)antibody. It is considered that the activity of $TGF-{\alpha}$ increased as tumor cell prolifierates. Immunocytochemistry and in situ hybridization techniques can be used to diagnose gastric cancer along with the use of ${\alpha}-feto$ protein and CEA.

• Nutrition Research and Practice
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• v.5 no.3
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• pp.185-191
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• 2011

In Korea, chestnut production is increasing each year, but consumption is far below production. We investigated the effect of chestnut extracts on antioxidant activity and anticancer effects. Ethanol extracts of raw chestnut (RCE) or chestnut powder (CPE) had dose-dependent superoxide scavenging activity. Viable numbers of MDA-MD-231 human breast cancer cells, DU145 human prostate cancer cells, and AGS human gastric cancer cells decreased by 18, 31, and 69%, respectively, following treatment with $200{\mu}g/mL$ CPE for 24 hr. CPE at various concentrations ($0-200{\mu}g/mL$) markedly decreased AGS cell viability and increased apoptotic cell death dose and time dependently. CPE increased the levels of cleaved caspase-8, -7, -3, and poly (ADP-ribose) polymerase in a dose-dependent manner but not cleaved caspase-9. CPR exerted no effects on Bcl-2 and Bax levels. The level of X-linked inhibitor of apoptosis protein decreased within a narrow range following CPE treatment. The levels of Trail, DR4, and Fas-L increased dose-dependently in CPE-treated AGS cells. These results show that CPE decreases growth and induces apoptosis in AGS gastric cancer cells and that activation of the death receptor pathway contributes to CPE-induced apoptosis in AGS cells. In conclusion, CPE had more of an effect on gastric cancer cells than breast or prostate cancer cells, suggesting that chestnuts would have a positive effect against gastric cancer.