• Journal of the Korean Society of Food Culture
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• v.35 no.3
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• pp.302-310
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• 2020

Although the age-standardized incidence of gastric cancer has decreased in Korea, it remains the second most common type of cancer. The purpose of this study was to analyze the phospholipid fatty acid compositions of gastric mucosa in gastric cancer. Cancerous mucosa and noncancerous mucosa adjacent to cancerous tissues were obtained from 29 patients who had undergone gastrectomy for gastric adenocarcinoma. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), and phosphatidylserine (PS) were separated from phospholipids by thin-layer chromatography, and fatty acids were analyzed by gas chromatography. In cancerous mucosa, saturated fatty acids of total phospholipids and stearic acid of PE and PC contents as well as total phospholipids were significantly more abundant than in noncancerous tissues. The ratios of ω6 fatty acid products to linoleic acid of PC, PE, PI, and PS contents as well as total phospholipids were significantly higher in cancerous mucosa than in noncancerous mucosa. Arachidonic acid levels of PE and PI were significantly higher, but the PC level was lower in cancerous mucosa. These results suggest that the characteristic differences in fatty acid compositions of phospholipids and their subfractions shown in gastric cancerous mucosa may be affected by changes in lipid metabolism in gastric carcinogenesis. Further studies on structural and functional changes in phospholipids related to gastric carcinogenesis will be needed.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.9
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• pp.4067-4070
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• 2014

Background: The Chinese Hui ethnic group has diverse origins, including Arab, Persian, Central Asian, and Mongol. The standardized mortality rate of gastric cancer in the Hui population is higher than the overall Chinese population. In this study, we investigated whether COX-2-765G>C polymorphism, an extensively studied polymorphism, contributes to gastric cancer and its precursor lesions (GPL) in the Chinese Hui ethnic group. Materials and Methods: COX-2-765G>C polymorphism was determined by pyrosequencing in 100 gastric cancer cases, 102 gastric cancerand its precursor lesions cases and 105 controls. Data were statistically analyzed using Chi-square tests and logistic regression models. Results: Among the Chinese Hui ethnic group COX-2-765 C allele carriers were at increased risk for gastric cancer (OR=1.977, 95%CI=1.104-3.541). We also found an interaction between COX-2 -765 C carriers and Helicobacter pylori infection and eating pickled vegetables. Conclusions: Our findings suggest a multi-step process of gene-environment interaction contributes to gastric carcinogenesis.

• Journal of Digestive Cancer Research
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• v.6 no.1
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• pp.6-10
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• 2018

The importance of signal transducer and activator of transcription 3 (STAT3) signaling in gastric carcinogenesis was firmly evaluated in the previous studies. Fully activated STAT3 induces various target genes involving tumor invasion and epithelial-mesenchymal transition (EMT), and mediates interaction between cancer cells and microenvironmental immune cells. Thus, suppression of STAT3 activity is an important issue for inhibition of gastric carcinogenesis and invasion. Unfortunately, data from clinical studies of direct inhibitor targeting STAT3 have been disappointing. SH2-containing protein tyrosine phosphatase 1 (SHP-1) effectively dephosphorylates and inhibits STAT3 activity, which has not been extensively studied gastric cancer research field. However, by summarizing recent data, it is evident that protein and gene expression of SHP-1 are minimal in gastric cancer cells, and induction of SHP-1 effectively downregulates phosphorylated STAT3 and inhibits cellular invasion in gastric cancer cells. Several SHP-1 inducers have been investigated in the experimental studies, including proton pump inhibitor, arsenic trioxide, and other natural compounds. Taken together, we suggest that modulation of SHP-1/STAT3 signaling axis may present a new way for treatment of gastric cancer, and development of effective SHP-1 inducer may be an important task in the future search field of gastric cancer.

• BMB Reports
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• v.46 no.1
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• pp.25-30
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• 2013

Gap junctions and their structural proteins, connexins (Cxs), have been implicated in carcinogenesis. To explore the involvement of Cx32 in gastric carcinogenesis, immunochemical analysis of Cx32 and proliferation marker Ki67 using tissue-microarrayed human gastric cancer and normal tissues was performed. In addition, after Cx32 overexpression in the human gastric cancer cell line AGS, cell proliferation, cell cycle analyses, and $p21^{Cip1}$ and $p27^{Kip1}$ expression levels were examined by bromodeoxyuridine assay, flow cytometry, real-time RT-PCR, and western blotting. Immunohistochemical study noted a strong inverse correlation between Cx32 and Ki67 expression pattern as well as their location. In vitro, overexpression of Cx32 in AGS cells inhibited cell proliferation significantly. $G^1$ arrest, up-regulation of cell cycle-regulatory proteins $p21^{Cip1}$ and $p27^{Kip1}$ was also found at both mRNA and protein levels. Taken together, Cx32 plays some roles in gastric cancer development by inhibiting gastric cancer cell proliferation through cell cycle arrest and cell cycle regulatory proteins.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.1077-1082
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• 2015

Recent studies have suggested that the RAS protein activator like-1 (RASAL1) functions as a tumor suppressor in vitro and may play an important role in the development of gastric cancer. However, whether or not RASAL1 suppresses tumor growth in vivo remains to be determined. In the present study, we investigated the role of RASAL1 in gastric carcinogenesis using an in vivo xenograft model. A lentiviral RASAL1 expression vector was constructed and utilized to transfect the human poorly differentiated gastric adenocarcinoma cell line, BGC-823. RASAL1 expression levels were verified by quantitative real-time RT-PCR and Western blotting analysis. Then, we established the nude mice xenograft model using BGC-823 cells either over-expressing RASAL1 or normal. After three weeks, the results showed that the over-expression of RASAL1 led to a significant reduction in both tumor volume and weight compared with the other two control groups. Furthermore, in xenograft tissues the increased expression of RASAL1 in BGC-823 cells caused decreased expression of p-ERK1/2, a downstream moleculein the RAS/RAF/MEK/ERK signal pathway. These findings demonstrated that the over-expression of RASAL1 could inhibit the growth of gastric cancer by inactivation of the RAS/RAF/MEK/ERK pathway in vivo. This study indicates that RASAL1 may attenuate gastric carcinogenesis.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6305-6310
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• 2012

Objectives: This study aimed to demonstrate the tyrosine phosphorylation motif (TPM) and 3' region structure of the Helicobacter pylori CagA gene as well as its SHP-2 binding activity in AGS cells and relation to gastric carcinogenesis. Methods: Sixteen clinical isolate H. pylori strains from eight duodenal ulcer and eight gastric adenocarcinoma patients were studied for CagA repeat sequence EPIYA motifs, C-terminal structure, and western blot analysis of CagA protein expression, translocation, and SHP-2 binding in AGS cells. Results: Except for strain 547, all strains from the gastric adenocarcinoma patients were positive for CagA by PCR and had three EPIYA copy motifs. Western blotting showed that all strains were positive for CagA protein expression (100%), CagA protein translocation (100%), and SHP-2 binding (100%). CagA protein expression was significantly higher in the gastric adenocarcinoma patients than in the duodenal ulcer patients (P=0.0023). CagA protein translocation and SHP-2 binding in the gastric adenocarcinoma patients were higher than those in the duodenal ulcer patients, but no significant differences were found between the two groups (P=0.59, P=0.21, respectively). Conclusions: The TPMs and 3' region structures of the H. pylori CagA gene in the duodenal ulcer and gastric adenocarcinoma patients have no significant differences.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.sup1
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• pp.83-92
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• 2008

Helicobacter pylori is the causative agent of chronic gastritis and has a role in the pathogenesis of peptic ulcer diseases, and gastric cancer. There have been reports suggesting a close link between these gastroduodenal disorders and a state of vitamin C deficiency. In this paper, the past, present and future perspectives on H. pylori infection and vitamin C will be discussed under the following view points. Since the ecological niche of H. pylori is the mucus layer and intercellular junctions of the gastric epithelium, the various kinds of host inflammatory cells motivated by the local and systemic immune responses cannot eliminate the microorganisms. When the invading foreign body is not removed, despite full activation of defense mechanisms, adverse consequences of the immune responses develop on the host gastric mucosa. The reasons for the body vitamin C depletion could be explained as follows; 1) the increased vitamin C consumption by increased oxygen free radical production through the prolonged hypersensitivity reactions in the gastric mucosa, 2) the increased vitamin C oxidation by the nitrite which is formed from nitrate reduction by the intragastric bacteria proliferated in the hypochlorhydric gastric cavity, 3) the strong ${\gamma}$-glutamyltranspeptidase activity of H. pylori which depletes the glutathiones in gastric mucosa. Depletion of glutathiones in the stomach favors irreversible oxidative destruction of ascorbic acid. Both persistent inflammatory burdens in the stomach by H. pylori and resultant vitamin C depletions synergistically and uninhibitedly might aggravate the hypothetical sequence of gastric carcinogenesis: atrophic gastritis${\rightarrow}$intestinal metaplasia${\rightarrow}$dysplasia${\rightarrow}$gastric adenocarcinoma. High intake of vitamin C could reverse the hypothetical sequence of the gastric carcinogenesis via direct and indirect effects on H. pylori and host-parasite relationships.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.945-950
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• 2014

Purpose: To explore the value of systemic inflammatory markers as independent prognostic factors and the extent these markers improve prognostic classification for patients with inoperable advanced or metastatic gastric cancer (GC) receiving palliative chemotherapy. Methods: We studied the prognostic value of systemic inflammatory factors such as circulating white blood cell count and its components as well as that combined to form inflammation-based prognostic scores (Glasgow Prognostic Score (GPS), Neutrophil-Lymphocyte Ratio (NLR), Platelet Lymphocyte Ratio (PLR), Prognostic Index (PI) and Prognostic Nutritional Index (PNI)) in 384 patients with inoperable advanced or metastatic gastric cancer (GC) receiving first-line chemotherapy. Univariate and multivariate analyses were performed to examine the impact of inflammatory markers on overall survival (OS). Results: Univariate analysis revealed that an elevated white blood cell, neutrophil and/or platelet count, a decreased lymphocyte count, a low serum albumin concentration, and high CRP concentration, as well as elevated NLR/PLR, GPS, PI, PNI were significant predictors of shorter OS. Multivariate analysis demonstrated that only elevated neutrophil count (HR 3.696, p=0.003) and higher GPS (HR 1.621, p=0.01) were independent predictors of poor OS. Conclusion: This study demonstrated elevated pretreatment neutrophil count and high GPS to be independent predictors of shorter OS in inoperable advanced or metastatic GC patients treated with first-line chemotherapy. Upon validation of these data in independent studies, stratification of patients using these markers in future clinical trials is recommended.

• Korean Journal of Veterinary Research
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• v.54 no.3
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• pp.171-177
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• 2014

Garlic and mugwort have long been used in traditional medicine to prevent various diseases. Several in vitro studies have reported protective efficacies of garlic and mugwort in cases of gastric cancer. In the present study, we investigated the cancer preventive effects of garlic and mugwort mixture extract (GME) in a Helicobacter (H.) pylori-associated gastric carcinogenesis mouse model. To induce gastric cancer, C57BL/6 mice were treated with N-methyl-N-nitrosourea and H. pylori. Various concentrations of GME (0, 100, 500, and 1,000 ppm) were then fed to the mice for 38 weeks, after which the tumor tissues were examined for histopathology, mucin histochemistry and ${\beta}$-catenin. The incidence of gastric tumors was significantly lower in the highest dose GME-treated mice (46.7%) than control mice (85.7%) (p < 0.05). The multiplicity and size of tumors were also significantly reduced by GME feeding in a dose-dependent manner (p < 0.01). Furthermore, GME suppressed the H. pylori-associated chronic inflammation measured by histologic grading of H. pylori density, chronic gastritis, glandular atrophy and intestinal metaplasia in non-tumorous gastric mucosae. Our data suggest that GME suppresses gastric tumorigenesis via suppression of H. pylori-associated chronic inflammation.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.6
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• pp.2757-2760
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• 2016

Gastric cancer (GC) is the fourth most prevalant cancer and the second leading cause of cancer-related mortality worldwide. As in other cancers gastric carcinogenesis is multifactorial involving environmental, genetic and epigenetic components. Epigenetic silencing due to hypermethylation of tumour suppressor genes is one of the key events in gastric carcinogenesis. This study was aimed to analyse the hypermethylation status of the E-Cadherin (CDH1) gene promoter in GCs in the ethnic Kashmiri population. In this study a total of 80 GC patients were recruited. Hypermethylation in tumour tissue was detected by methylation specific PCR (MS-PCR). Hypermethylation of CDH1 promoter was observed in 52 (65%) of gastric carcinoma cases which was significantly much higher than adjacent normal tissue [$p{\leq}0.0001$]. Further the frequency of CDH1 promoter methylation was significantly different with intestinal and diffuse types of gastric cancer [55.7% vs 82.1%; p<0.05]. Moreover females and cases with lymph node invasion had higher frequencies of CDH1 hypermethylation [$P{\leq}0.05$]. Thus the current data indicate a vital role of epigenetic alteration of CDH1 in the causation and development of gastric cancer, particularly of diffuse type, in our population.