• Journal of Gastric Cancer
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• v.3 no.1
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• pp.19-25
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• 2003

Purpose: Dysregulation of apoptosis may attribute to development of cancer by abnormally prolonging cell viability with accumulation of transforming mutations. Survivin and HIAP (Human Inhibitors of Apoptosis)-1 were recently described as apoptosis inhibitors. Their pathogenic roles in gastric cancer are largely unknown. In the present study, we examined the expression of survivin and HIAP-1 in gastric cancer tissues and cell lines in order to elucidate the roles of survivin and HIAP-1 in the process of gastric carcinogenesis. Materials and Methods: Eight gastric cancer cell lines and five gastric cancer tissues were studied. The expression of survivin and HIAP-1 were evaluated by reverse transcription -polymerase chain reaction (RT-PCR), immunohistochemistry, and Western blot. Results: Western blot and RT-PCR analysis revealed survivin and HIAP-1 expression in all gastric cancer cell lines. Increased expression of survivin and HIAP-1 were found in all cases of gastric cancer tissues compared to normal tissues by Western blot analysis. In immunohistochemical analysis tumor cells were stained with anti-survivin and anti-HIAP-1 antibodies. Cell cycle dependence of survivin expression was preserved in gastric cancer cell lines. Conclusion: The results indicate that increased expression of survivin and HIAP-1 genes may play an important role in gastric cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.6031-6034
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• 2013

This study describes recent trends in incidence, survival and prevalence of subgroups of esophageal and gastric cancer in Linzhou city between 2003 and 2009. Data of esophageal and gastric cancer for the period of interest were extracted from the Linzhou Cancer Registry. Using information on tumor morphology or anatomical site, data were divided into six groups; esophageal squamous cell carcinoma, esophageal adenocarcinoma, other and unspecified types of esophageal cancer, and cardia, non-cardia, and unspecified anatomical site of stomach cancer. Incidence, survival and prevalence rates for each of the six cancer groups were calculated. The majority of esophageal cancers were squamous cell carcinomas (82%). Cardiac cancer was the major gastric cancer group (64%). The incidence of esophageal squamous cell carcinoma and gastric cardiac cancer increased between 2003 and 2009. Both esophageal and gastric cancer had a higher incidence in males compared with females. Overall survival was poor in all sub-groups with 1 year survival ranging from 45.9 to 65.6% and 5 year survival ranging from 14.7 to 30.5%. Prevalence of esophageal squamous cell carcinoma and gastric cardiac cancer was high (accounting for 80% overall). An increased focus on prevention and early diagnosis, especially in esophageal squamous cell carcinoma and gastric cardiac cancer, is required.

• Journal of Gastric Cancer
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• v.11 no.1
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• pp.16-22
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• 2011

Purpose: Eupatilin is an antioxidative flavone and a phytopharmaceutical derived from Artemisia asiatica. It has been reported to possess anti-tumor activity in some types of cancer including gastric cancer. Eupatilin may modulate the angiogenesis pathway which is part of anti-inflammatory effect demonstrated in gastric mucosal injury models. Here we investigated the anti-tumor effects of eupatilin on gastric cancer cells and elucidated the potential underlying mechanism whereby eupatilin suppresses angiogenesis and tumor growth. Materials and Methods: The impact of eupatilin on the expression of angiogenesis pathway proteins was assessed using western blots in MKN45 cells. Using a chromatin immunoprecipitation assay, we tested whether eupatilin affects the recruitment of signal transducer and activator of transcription 3 (STAT3), aryl hydrocarbon receptor nuclear translocator (ARNT) and hypoxia-inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) to the human VEGF promoter. To investigate the effect of eupatilin on vasculogenesis, tube formation assays were conducted using human umbilical vein endothelial cells (HUVECs). The effect of eupatilin on tumor suppression in mouse xenografts was assessed. Results: Eupatilin significantly reduced VEGF, ARNT and STAT3 expression prominently under hypoxic conditions. The recruitment of STAT3, ARNT and HIF-$1{\alpha}$ to the VEGF promoter was inhibited by eupatilin treatment. HUVECs produced much foreshortened and severely broken tubes with eupatilin treatment. In addition, eupatilin effectively reduced tumor growth in a mouse xenograft model. Conclusions: Our results indicate that eupatilin inhibits angiogenesis in gastric cancer cells by blocking STAT3 and VEGF expression, suggesting its therapeutic potential in the treatment of gastric cancer.

• Journal of Gastric Cancer
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• v.3 no.2
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• pp.88-92
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• 2003

Purpose: Mounting evidence suggests that alterations of Akt/protein kinase B (PKB) play an important role in tumorigenesis. Phosphorylated Akt regulates many of the key effector molecules involved in apoptosis, angiogenesis, and cell-cycle progression during tumorigenesis. The expression of phosphorylated Akt has been described in some human malignancies, but not in primary human gastric cancer. The purpose of this study was to explore the expression status of phosphorylated Akt protein in gastric carcinomas. Materials and Methods: In the current study, we analyzed the expression of phosphorylated Akt protein in 60 advanced gastric adenocarcinomas by using immunohistochemistry and a tissue microarray approach. Results: Immunopositivity (defined as $\geq\30\%$) was observed for the phosphorylated Akt in 42 ($70\%$) of the 60 cancers. Normal gastric mucosal cells showed no or weak expression of phosphorylated Akt protein. Conclusion: Taken together, these results indicate that Akt is frequently activated in gastric adenocarcinoma cells and suggest that phosphorylayed Akt may play a role in the development of human gastric adenocarcinomas.

• BMB Reports
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• v.47 no.1
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• pp.39-44
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• 2014

Increasing data shows miR-29a is a key regulator of oncogenic processes. It is significantly down-regulated in some kind of human tumors and possibly functionally linked to cellular proliferation, survival and migration. However, the mechanism remains unclear. In this study, we report miR-29a is significantly under-expressed in gastric cancer compared to the healthy donor. The microvessel density is negatively related to miR-29a expression in gastric cancer tissues. The ectopic expression of miR-29a significantly inhibits proliferation and invasion of gastric cancer cells. Furthermore, western blot combined with the luciferase reporter assays demonstrate that vascular endothelial growth factor A (VEGF-A) is direct target of miR-29a. This is the first time miR-29a was found to suppress the tumor microvessel density in gastric cancer by targeting VEGF-A. Taken together, these results suggest that miR-29a is a tumor suppressor in gastric cancer. Restoration of miR-29a in gastric cancer may be a promising therapeutic approach.

• Biomedical Science Letters
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• v.28 no.2
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• pp.92-100
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• 2022

Ginkgo biloba Leaf Extract (GBE) is an extract from leaves of the Ginkgo biloba tree, widely used as a health supplement. GBE can inhibit the proliferation of several types of tumor cell. Although it is known to have anti-cancer effects in breast cancer and skin cancer, research related to gastric cancer is still insufficient. Based on results showing anti-cancer effects on solid cancer, we aimed to determine whether GBE has similar effects on gastric cancer. In this study, the anti-cancer effect of GBE in gastric adenocarcinoma was investigated by confirming the cell proliferation inhibitory effect of AGS cells. We also evaluated whether GBE regulates expression of the tumor suppressor protein p53 and Rb. GBE has apoptotic effects on AGS cells that were confirmed by changes in anti-apoptosis protein Bcl-2, Bcl-xl and pro-apoptosis protein Bax levels. Wound healing and cell migration were also decreased by treatment with GBE. Furthermore, we verified the effects of GBE on mitogenic signaling by investigating AKT target gene expression levels and revealed downregulated Sod2 and Bcl6 expression. We also confirmed that expression of inflammation-related genes decreased in a time-dependent manner. These results indicate that GBE has an anti-cancer effect on human gastric cancer cell lines. Further research on the mechanism of the anti-cancer effect will serve as basic data for possible anti-cancer drug development.

• Journal of Gastric Cancer
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• v.20 no.3
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• pp.300-312
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• 2020

Purpose: Circular RNAs (circRNAs) are a new class of RNA molecules whose function is largely unknown. There is a growing evidence that circRNAs play an important regulatory role in the progression of a variety of human cancers. However, the exact roles and the mechanisms of circRNAs in gastric cancer are not clear. In this study, we aimed to elucidate the mechanism of hsa_circ_0005556. Materials and Methods: Real-time quantitative polymerase chain reaction was used to detect the expression of hsa_circ_0005556, miR-4270, and matrix metalloproteinase-19 (MMP19) in gastric cancer tissues and cell lines. The expression of hsa_circ_0005556 in gastric cancer cells was silenced by lentivirus, and cell proliferation, invasion, migration, and tumorigenesis in nude mice were assessed to evaluate the function of hsa_circ_0005556 in gastric cancer. Results: The expression of hsa_circ_0005556 in gastric cancer tissues and gastric cancer cell lines was higher compared to normal controls. In vitro, the downregulation of hsa_ circ_0005556 significantly inhibited proliferation, migration, and invasion of gastric cancer cells. In vivo, the downregulation of hsa_circ_0005556 suppressed tumor growth in nude mice. Conclusions: Our study shows that the hsa_circ_0005556/miR-4270/MMP19 axis is involved in proliferation, migration, and invasion of gastric cancer cells through the competing endogenous RNA (ceRNA) mechanism.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.107-112
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• 1999

Effect of solvent extracts and juice supernatants from kimchis on the growth of various human cancer cells was studied, comparing with the actions on the normal cells. Inhibitory effect of kimchi extracts on[3H] thymidine incorporation n cancer cells was also investigated. The methanol extract, hexane extract and methanol soluble fraction (MSF) of 3-week fermented kimchi did not have growth inhibitory effect on Ac2F rat normal liver cells at the concentrations of 0.5~2%. However, marked decrease in the growth of AGS human gastric cancer cells was shown by the treatment of those extacts. The juice from the kimchi samples also suppressed the growth of K-562 human leukemia cells and MG-63 human osteosarcoma cells. Especially, the juice of 3-week fermented kimchi exhibited the strong growth inhibitory effect in MG-63 human osteosarcoma cells. At the photomicrographs, growth inhibition and morphological change of the cells treated with kimchi juice were observed. And the solvent extracts of 3-week fermented kimchi suppressed the growth of cancer morethan the extracts or juices from fresh and 6-week fermented kimchi. When AGS human gastric cancer cels were treated with the extracts of 3-week fermented kimchi, [3H] thymidine incorporation in the cells also decreased. These results showed that kimchi extracts and juices had growth inhibitory effects on human osteosarcoma, leukemia and gastric cancer cells, but had no toxicity to the normal cells. We suggest that kimchi might have anticancer effect in part due to inhibition of the growth and DNA synthesis of cancer cells.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1377-1382
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• 2012

Morphine is not only an analgesic treating pain for patients with cancer but also a potential anticancer drug inhibiting tumor growth and proliferation. To gain better insight into the involvement of morphine in the biological characteristics of gastric cancer, we investigated effects on progression of gastric carcinoma cells and the expression of some apoptosis-related genes including caspase-9, caspase-3, survivin and NF-${\kappa}B$ using the MGC-803 human gastric cancer cell line. The viability of cells was assessed by MTT assay, proliferation by colony formation assay, cell cycle progression and apoptosis by flow cytometry and ultrastructural alteration by transmission electron microscopy. The influences of morphine on caspase-9, caspase-3, survivin and NF-${\kappa}B$ were evaluated by semi-quantitative RT-PCR and Western blot. Our data showed that morphine could significantly inhibit cell growth and proliferation and cause cell cycle arrest in the G2/M phase. MGC-803 cells which were incubated with morphine also had a higher apoptotic rate than control cells. Morphine also led to morphological changes of gastric cancer cells. The mechanism of morphine inhibiting gastric cancer progression in vitro might be associated with activation of caspase-9 and caspase-3 and inhibition of survivin and NF-${\kappa}B$.

• Proceedings of the Korean Society of Toxicology Conference
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• 2006.11a
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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.