Expression of tissue inhibitors of metalloproteinases (TIMPs) in gastric cancer

Matrix 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). Sixty-five patients who underwent surgery for gastric cancer in 1992 at Chonnam National University Hospital were selected for this study. The primary selection criteria were the availability of formalin-fixed and paraffin-embedded blocks and sufficient clinical follow-up for tumor-specific survival analysis. In this study, we examined the expression of TIMP-1 and TIMP-2 in human gastric cancer tissue by in situ hybridization and immunohistochemistry, and the correlation between their expression and clinicopathological parameters. TIMP-1 and TIMP-2 expressions were detected predominantly in the peritumor stromal cells rather than tumor cells themselves. Immunohistochemical stainings were concordant with the result obtained by in situ hybridization. The intensity of TIMP-1 immunohistochemical stromal staining correlated with tumor stage (P = 0.009) and patient survival (P = 0.025). However, the intensity of TIMP-2 immunohistochemical stromal staining did not correlate with tumor stage (P = 0.339) and patient survival (P = 0.474). The correlation between the increased TIMP-1 expression and cancer stage noted in this study reflects a role of TIMP-1 in predicting the aggressive behavior of gastric cancer. TIMP-2 expression did not correlate with clinicopathological parameters. However, expression of TIMP-1 and the possible additional value of TIMP-2 should be further explored in determining the prognosis of gastric cancer.