• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6481-6486
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• 2013

Background: Our previous study demonstrated cytotoxicity of a crude extract from Patrinia heterophylla Bunge (PHEB). In the present study, we aimed to investigate the effects of isovaltrate acetoxyhydrin (IA) isolated from PHEB on the gastric cancer cell SGC-7901, in order to explore a potential treatment for gastric cancer. Methods: MTT assays were employed to determine the effects of IA on cell vitality and proliferation, with monitoring of cell morphology changes and examination of apoptosis with Annexin V-PI staining. Flow cytometry was used to assess cell cycle progression and mitochondrial membrane potential. The activity of caspase 3, 9 was evaluated by spectrophotometry, and the protein levels of Bax, Bcl2 and Cyclin B1 were analyzed with Western blotting of total proteins extracted from cultured cells. Results: The results demonstrated direct toxicity of IA towards SGC-7901 cells. Evidence of apoptosis included blebbing and chromatin condensation. Annexin V-PI assays revealed early apoptosis, involving rapid depolarization of mitochondrial membranes and activity of caspase 3, 9 signaling pathways. Western blotting showed that Bcl2 and Bax proteins was down- and up-regulated, respectively, and cyclin B1 was up-regulated. Cell cycle analysis further indicated that IA could induce G2/M phase arrest in SGC-7901 cells. Conclusions: In conclusion, we believe that IA induces apoptosis of SGC-7901 cells, therefore providing a potential therapeutic agent for treatment of gastric cancer.

• 대한약침학회지
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• 제16권3호
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• pp.39-45
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• 2013

Objectives: Buxus Microphylla var. Koreana Nakai Extract (BMKNE) is used as a folk remedy for malaria and veneral disease. In the present study, we investigated the effects of BMKNE in the growth and the survival of AGS cells, the most common human gastric adenocarcinoma cell lines. Methods: The AGS cells were treated with varying concentrations of BMKNE. Analyses of the sub G1 peak, the caspase-3 and -9 activities, and the mitochondrial depolarization were conducted to determine whether AGS cell death occured by apoptosis. Also, to identify the role of transient receptor potential melastatin (TRPM) 7 channels in AGS cell growth and survival, we used human embryonic kidney (HEK) 293 cells overexpressed with TRPM7 channels. Results: Experimental results showed that the sub G1 peak, the caspase-3 and -9 activities, and the mitochondrial depolarization were increased. Therefore, BMKNE was found to induce the apoptosis of these cells, and this apoptosis was inhibited by SB203580 (a p38 mitogen-activated protein kinase (MAPK) inhibitor), and by a c-jun NH2-terminal kinase (JNK) II inhibitor. Furthermore, BMKNE inhibited TRPM7 currents and TRPM7 channel over-expressions in HEK 293 cells, exacerbating BMKNE-induced cell death. Conclusions: These findings indicate that BMKNE inhibits the growth and the survival of gastric cancer cells due to a blockade of the TRPM7 channel's activity and MAPK signaling. Therefore, BMKNE is a potential drug for treatment of gastric cancer, and both the TRPM7 channel and MAPK signaling may play an important role in survival in gastric cancer cells.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2006년도 추계학술대회
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• pp.19-24
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• 2006

Mothers against decapentaplegic homolog 4 (SMAD4) is a tumor suppressor gene associated with gastrointestinal carcinogenesis. The aim of the present study was to characterize more precisely its role in the development and progression of human gastric carcinoma. In this study, using tissue microarray analysis of 283 gastric cancers and related lesions, we found loss of SMAD4 protein expression in the cytoplasm (36/114, 32%) and in the nucleus (46/114, 40%) of gastric cancer cells. The loss of nuclear SMAD4 expression in primary tumors correlated significantly with poor survival, and was an independent prognostic marker in multivariate analysis. We also found a substantial decrease in SMAD4 expression at both the RNA and protein level in several human gastric carcinoma cell lines. To identify the genetic and/or epigenetic mechanisms of altered SMAD4 expression in gastric carcinoma, loss of heterozygosity (LOH), promoter hypermethylation, and exon mutations were examined. We found that LOH (20/70, 29%) and promoter hypermethylation (4/73, 5%) were associated with the loss of SMAD4 expression. SMAD4 protein levels wore also affected in certain gastric carcinoma cell lines following incubation with Mc132, a proteasome inhibitor. Taken together, our results indicate that the loss of SMAD4, especially loss of nuclear SMAD4 expression, is involved in gastric cancer progression. The loss of SMAD4 in gastric carcinomas is due to several mechanisms, including LOH, hypermethylation, and proteasome degradation.

• BMB Reports
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• 제57권4호
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• pp.188-193
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• 2024

Gastric cancer (GC), a leading cause of cancer-related mortality, remains a significant challenge despite recent therapeutic advancements. In this study, we explore the potential of targeting cell surface glucose-regulated protein 94 (GRP94) with antibodies as a novel therapeutic approach for GC. Our comprehensive analysis of GRP94 expression across various cancer types, with a specific focus on GC, revealed a substantial overexpression of GRP94, highlighting its potential as a promising target. Through in vitro and in vivo efficacy assessments, as well as toxicological analyses, we found that K101.1, a fully human monoclonal antibody designed to specifically target cell surface GRP94, effectively inhibits GC growth and angiogenesis without causing in vivo toxicity. Furthermore, our findings indicate that K101.1 promotes the internalization and concurrent downregulation of cell surface GRP94 on GC cells. In conclusion, our study suggests that cell surface GRP94 may be a potential therapeutic target in GC, and that antibody-based targeting of cell surface GRP94 may be an effective strategy for inhibiting GRP94-mediated GC growth and angiogenesis.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6757-6760
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• 2013

Gastric cancer is one of the most frequently occurring malignancies in the world. Development of multiple drug resistance (MDR) to chemotherapy is known as the major cause of treatment failure for gastric cancer. Multiple drug resistance 1/P-glycoprotein (MDR1/p-gp) contributes to drug resistance via ATP-dependent drug efflux pumps and is overexpressed in many solid tumors including gastric cancer. To investigate the role of MDR1 knockdown on drug resistance reversal, we knocked down MDR1 expression using shRNA in drug resistant gastric cancer cells and examined the consequences with regard to adriamycin (ADR) accumulation and drug-sensitivity. Two shRNAs efficiently inhibited mRNA and protein expression of MDR1 in SGC7901-MDR1 cells. MDR1 knockdown obviously decreased the ADR accumulation in cells and increased the sensitivity to ADR treatment. Together, our results revealed a crucial role of MDR1 in drug resistance and confirmed that MDR1 knockdown could reverse this phenotype in gastric cancer cells.

• Journal of Gastric Cancer
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• 제6권2호
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• pp.91-96
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• 2006

목적: 일반적으로 DNA가 손상된 세포들은 사멸되거나 적절히 손상된 부위를 복구하여 항상성을 유지하거나, 손상된 DNA를 가지고 계속 증식하여 결국 암으로 진행한다. 그러므로 세포자멸사와 세포증식의 균형의 변화는 조직 항상성 및 암 발생의 중요한 조절기전이다. 이에 본 연구자들은 위샘종 또는 위샘암종 조직을 대상으로 세포 사멸 및 세포증식의 정도를 보고자 하였다. 대상 및 방법: 내시경적으로 절제된 위샘종 41예, 외과 수술로 절제된 위샘암종 100예를 대상으로 면역조직화학적 검사를 시행하여 Ki-67 labelling 지수를 구하고, TUNEL 방법을 이용하여 세포자멸사 지수를 구하여 위샘종에서의 이형성 정도에 따른 발현도의 차이 및 위샘암종에서의 조직분류 및 병기에 따른 발현도의 차이를 관찰하였다. 결과: Ki-67 labelling 지수는 위샘종 $51.90{\pm}1.45$, 위샘암종 $55.33{\pm}0.94$로서 위샘암종에서 의의 있게 높았다(P<0.05). 세포자멸사 지수는 위샘종 $53.27{\pm}2.67$, 위샘암종 $42.41{\pm}1.32$로서 위샘종에서 의의 있게 높았다(P<0.05). 위샘종에서 이형성에 따른 Ki-67 labelling 지수 및 세포자멸사 지수는 차이가 없었다. 위샘암종에서 Ki-67 labelling 지수 및 세포자멸사 지수는 Lauren 분류법에 의한 장형과 미만형, 조기 위암과 진행성 위암, 림프절 전이 유무, TNM 분류에 따른 각 군 간의 통계학적 차이는 보이지 않았다. 결론: 샘암종에서의 세포자멸사 지수와 Ki-67 labelling 지수에 대한 연구에서 위샘종은 위샘암종보다 좀 더 정적인 결과를 보이고, 위암발생에서는 세포증식이 중요한 역할을 하나 이 두 지수가 위암의 조직학적 분류 및 병기에 따른 예후와는 관련이 없었다.

• BMB Reports
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• 제46권6호
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• pp.316-321
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• 2013

Gastric cancer remains the main cause of cancer death all around the world, and upregulated activation of the nonreceptor tyrosine kinase c-SRC (SRC) is a key player in the development. In this study, we found that expression of Src is also increased in clinical gastric cancer samples, with the protein level increased more significantly than that at the RNA level. Further study revealed that miR34a and miR203, two tumor suppressive miRNAs, inversely correlate with the expression of Src. Restoration of miR34a and miR203 decreased Src expression in gastric cancer cell lines, which in turn inhibited cell growth and cell migration. In summary, our study here revealed that posttranscriptional regulation of Src contributes to the deregulated cell growth and metastasis in gastric cancer, and targeting Src by miR34a or miR203 mimics would be a promising strategy in therapy.

• 동의생리병리학회지
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• 제27권1호
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• pp.92-98
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• 2013

Bee Venom(below BV) has been used in alternative medicine to treat the diseases, such as pain diseases. BV contains a variety of peptides, including melittin, apamin, adolapin, MCD peptide, enzymes(i.e. PLA2), amines(i.e. histamine and epinephrine), and nonpeptide components. The two main components of BV are melittin and PLA2. The cell cytotoxic effects through the activation of PLA2 by melittin have been suggested to be the critical mechanism for the depress of cancer cell. Melittin and PLA2 have been reported to induce apoptosis and to possess anti-cancer effects and neurite outgrowth in PC12 cells. Analysis of proliferation was confirmed by MTT assay. BV decreased cell number through dose- and duration-dependent manner and these effects are apparent at a concentration of 3 ${\mu}g/ml$. To observe which signaling molecules will be activated by BV, phosphorylation of ERK, p38 MAPK, JNK and ERM were examined by Western blot analysis. To study the long term effect of BV in human gastric adenocarcinoma cell lines, the image of cells treated with BV for 4 days were obtained. BV was shown to exhibit anti-cancer activity in human gastric adenocarcinoma cell lines at a broad range of concentrations of 3 ${\mu}g/ml$. ERK, p38 MAPK and JNK were found to increase in BV treated cells. However, ERM which known to be involved in the cell death, was gradually decreased to 30minutes after addition 3 ${\mu}g/ml$ of BV. These results provide a possible BV-induced inhibitory signal for cancer proliferation that is initiated by the decrease in ERM activity. Moreover, it is likely that the activation of ERK, p38 MAPK and JNK are required for the BV-induced inhibition of cancer proliferation.

• Journal of Korean Neurosurgical Society
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• 제56권1호
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• pp.51-54
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• 2014

Gastric cancer is one of the most common causes of cancer-related death in Asian countries, including Korea. We experienced a case of leptomeningeal carcinomatosis (LC) from gastric cancer that was originally misdiagnosed as vestibular schwannoma based on the similar radiological characteristics. To our knowledge, LC from gastric cancer is very rare. In conclusion, our experience with this case suggests that clinicians should consider the possibility of delayed leptomeningeal metastasis when treating patients with gastric cancer.

• Molecules and Cells
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• 제41권6호
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• pp.532-544
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• 2018

Gastrointestinal stromal tumours (GIST) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. In order to investigate a new treatment fot GIST, we hypothesized the effect of miR-374b targeting PTEN gene-mediated PI3K/Akt signal transduction pathway on proliferation and apoptosis of human gastrointestinal stromal tumor (GIST) cells. We obtained GIST tissues and adjacent normal tissues from 143 patients with GIST to measure the levels of miR-374b, PTEN, PI3K, Akt, caspase9, Bax, MMP2, MMP9, ki67, PCNA, P53 and cyclinD1. Finally, cell viability, cell cycle and apoptosis were detected. According to the KFGG analysis of DEGs, PTEN was involved in a variety of signaling pathways and miRs were associated with cancer development. The results showed that MiR-374b was highly expressed, while PTEN was downregulated in the GIST tissues. The levels of miR-374b, PI3K, AKT and PTEN were related to tumor diameter and pathological stage. Additionally, miR-374b increased the mRNA and protein levels of PI3K, Akt, MMP2, MMP9, P53 and cyclinD1, suggesting that miR-374b activates PI3K/Akt signaling pathway in GIST-T1 cells. Moreover, MiR374b promoted cell viability, migration, invasion, and cell cycle entry, and inhibited apoptosis in GIST cells. Taken together, the results indicated that miR-374b promotes viability and inhibits apoptosis of human GIST cells by targeting PTEN gene through the PI3K/Akt signaling pathway. Thus, this study provides a new potential target for GIST treatment.