[Significance in gene expression of matrix metalloproteinase-9, urokinase-type plasminogen activator and tissue inhibitor of metalloproteinase for metastases of gastric and/or colo-rectal cancer].

In order to clarify the role of matrix metalloproteinase-9 (MMP-9), urokinase-type plasminogen activator (uPA) and tissue inhibitor of metalloproteinase (TIMP) in metastases of gastroenterological cancer, their gene expression in the primary lesions on 47 gastric or 48 colorectal cancer patients was examined by RT-PCR method. 1) The expression of MMP-9, uPA, and TIMP was observed in 55.3%, 66.0% and 87.2% of gastric cancer and in 54.2%, 70.8%, and 89.6% of colorectal cancer, respectively. 2) In the cases with either peritoneal dissemination or lymph node metastases, the incidence of gene expression of MMP-9 was significantly higher in comparison to the cases without those metastases. The same result was observed as for uPA. 3) In the cases with liver metastases, the incidence of gene expression of MMP-9 was significantly higher in comparison to the cases without liver metastasis. The same result was observed as for uPA. The above results indicate that MMP-9 and uPA might play important roles in the peritoneal and lymph node metastases in gastric cancer and in liver metastasis in colorectal cancer. Therefore the investigation of their gene expression in the primary lesions of cancer could be one of the useful methods for the prediction of metastasis, leading to the best decision as to the treatment.