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OBJECTIVE: Oxidative stress is linked to increased risk of gastric cancer and matrix metalloproteinases (MMPs) are important in the invasion and metastasis of gastric cancer. We aimed to analyze the effect of the accumulation of oxidative stress in the gastric cancer MKN-45 and 23132/87 cells following hydrogen peroxide (H2O2) exposure on the expression patterns of MMP-1, MMP-3, MMP-7, MMP-9, MMP-10, MMP-11, MMP-12, MMP-14, MMP-15, MMP-17, MMP-23, MMP-28, and ß-catenin genes. METHODS: The mRNA transcripts in the cells were determined by RT-PCR. Following H2O2 exposure, oxidative stress in the viable cells was analyzed by 2',7'-dichlorofluorescein diacetate (DCFH-DA). Caffeic acid phenethyl ester (CAPE) was used to eliminate oxidative stress and the consequence of H2O2 exposure and its removal on the expressions of the genes were evaluated by quantitative real-time PCR. RESULTS: The expressions of MMP-1, MMP-7, MMP-14, MMP-15, MMP-17 and ß-catenin in MKN-45 cells and only the expression of MMP-15 in 23132/87 cells were increased. Removal of the oxidative stress resulted in decrease in the expressions of MMP genes of which the expressions were increased after H2O2 exposure. ß-catenin, a transcription factor for many genes including MMPs, also displayed decreased levels of expression in both of the cell lines following CAPE treatment. CONCLUSIONS: Our data suggest that there is a remarkable link between the accumulation of oxidative stress and the increased expressions of MMP genes in the gastric cancer cells and MMPs should be considered as potential targets of therapy in gastric cancers due to its continuous exposure to oxidative stress.
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The thermophilic microorganism Geobacillus thermoleovorans ARTRW1 was isolated from water samples collected in the Armutlu hot spring in Turkey. Here, the whole-genome sequence and its annotations are reported.
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BACKGROUND: The gastric epithelium is continuously exposed to toxic reactive oxygen species and matrix metalloproteinases (MMPs) are the enzymes known for their roles in the invasion of tumor cells. Here, we report the suppression of matrix metalloproteinase 3 (MMP-3) in gastric cancer cell line AGS by small interfering RNA (siRNA) transfection and its potential role in gastric cancers. METHODS: Oxidative stress in the cell lines was assessed following H2O2 exposure using an oxidative stress marker, 2,7-dichlorofluorescein diacetate (DCFDA). Transfection of cells with small interfering RNA specific to MMP-3, Transwell invasion assay, quantitative reverse transcriptase polymerase chain reaction analysis, and over-expression of MMP-3 were used to determine the potential role of MMP-3 gene in gastric cancers. RESULTS: The silencing of the MMP-3 gene resulted in a decrease of invading AGS while the over-expression of it caused an increase in the invading cells compared to the untreated control cells. Moreover, it also caused a 4.1 fold increase in matrix metalloproteinase 10 (MMP-10) and a 7.4 fold decrease in matrix metalloproteinase 15 (MMP-15) mRNA expression levels. CONCLUSIONS: Our results show that the silencing of the MMP-3 gene decreases the number of invading AGS cells and additionally, affects the expressions of MMP-10 and MMP-15, suggesting that targeting the MMP-3 gene in gastric cancers might be a therapeutic approach due to its effects on the invasion of AGS cells and the expression of the MMP-15 gene.