P-0026 Matrix Metalloproteinase Gene Expressions and Oxidative Stress in Gastric Cancer

Abstract

ABSTRACT Introduction Chronic inflammation in gastric tissue owing to persistent oxidative stress has been associated with different complex stages involved in carcinogenesis. Matrix metalloproteinases (MMPs) are zinc dependent endopeptidases that are capable of degrading extracellular matrix proteins. This feature provides them to take important roles in the invasion and metastasis of gastric cancer. In this study, the changes in the expression levels 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 b-catenin genes were analyzed following H2O2 exposure of gastric carcinoma MKN-45 and 23132/87 cell lines to understand whether there is an association between oxidative stress in gastric cancer cells and MMP gene expressions. Methods MKN-45 and 23132/87 gastric cancer cell lines were exposed to 50-200 µM concentrations of H2O2. The mRNA transcripts in these cells were determined by RT-PCR. After H2O2 exposure, oxidative stress in the viable cells was analyzed by DCFH-DA (2’, 7’- dichlorofluoresceindeacetate). Caffeic acid phenethyl ester (CAPE) was used to remove oxidative stress and the consequence of H2O2 exposure and the removal of oxidative stress on the expressions of the genes were determined by quantitative real time PCR. Results The expressions of MMP-1, MMP-7, MMP-14, MMP-15, MMP-17 and b-catenin in MKN-45 cells increased after the exposure of H2O2. Following 12 hours of H2O2 application, MMP-14 displayed 1.4, 4.4, and 2.03 fold increase whereas the expression of MMP-1 gene was nearly similar at all the H2O2 concentrations. Also, 24 hours of H2O2 application resulted with 2.45, 1.7, 0.8 (80%) fold increase and 4.6, 4.9, and 6.1 times increase for MMP-14 and MMP-1, respectively. The expression of MMP-15 was observed only in 23132/87 cells. Subsequent to 24 hours of H2O2 exposure, 3, 3.9, 3.4 fold increase in the expression of MMP-15, and 5.05, 5.1, and 4.3 fold increase in the expression of MMP-17 gene were demonstrated at different concentrations of H2O2, respectively. Elimination of the oxidative stress resulted in decrease in the expressions of the MMPs of which the expressions were increased after H2O2 exposure. The MMP-1 and MMP-7 genes showed a fold of 4.7 and 8.7 decrease following CAPE treatment compared to the H2O2 exposed cells, respectively. Also, 1.3 and 10.8 fold decrease in the expression of the MMP-15 gene was determined. The expressions of MMP-14 and MMP-17 genes that were only expressed in MKN-45 cells were decreased 11.2 and 0.38 (38%) fold, respectively, after the removal of oxidative stress. b-catenin, a transcription factor for many genes including MMPs, also displayed decreased levels of expression in both of the cell lines following CAPE treatment. Conclusion According to our data, there is a significant relationship between the accumulation of oxidative stress and the increased expressions of MMPs in the gastric cancer cells. Owing to this, MMPs should be regarded as potential therapeutic target in gastric cancers due to the continuous exposure of gastric tissue to oxidative stress. This project was granted by TUBITAK 105S352 (SBAG-K-110) and by the Scientific Research Fund of Faith University (P50030703).