AbstractBackground and ObjectivesMatrix metalloproteinases (MMPs) are one of the major classes of proteolytic enzymes involved in tumor invasion and metastasis, being inhibited by naturally occurring tissue inhibitors of metalloproteinases (TIMPs). We examined mRNA expression for MMP‐2, MMP‐7, MMP‐9, MT1‐MMP, TIMP‐1, and TIMP‐2 in human gastric adenocarcinoma tissues, and the correlation between their expression and clinicopathological variables.MethodsGastric tissue samples from 72 patients with gastric adenocarcinoma were available for this study. To determine mRNA expression for MMP‐2, MMP‐7, MMP‐9, MT1‐MMP, TIMP‐1, and TIMP‐2, semiquantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR) was carried out on tumor and normal tissues, respectively.ResultsMean MMP‐2, MMP‐7, MMP‐9, MT1‐MMP, TIMP‐1, and TIMP‐2 mRNA expression in the gastric adenocarcinomas was significantly higher than in the normal tissue. In terms of the invasion of the tumor, lymph node metastasis, and tumor stage of gastric adenocarcinoma, the differences in MMP‐2, MMP‐7, MMP‐9, and MT1‐MMP mRNA expression levels were significant. MMP‐2, MMP‐7, MMP‐9, MT1‐MMP, TIMP‐1, and TIMP‐2 mRNA expression did not differ significantly in relation to histological type of gastric adenocarcinoma.ConclusionThe correlation between the increased expression of MMP‐2, MMP‐7, MMP‐9, and MTI‐MMP and clinicopathological parameters reflects a role in predicting the aggressive behavior of gastric cancer. J. Surg. Oncol. 2011; 103:243–247. © 2010 Wiley‐Liss, Inc.