Overexpression of matrix metalloproteinase-7 mRNA in human colon carcinomas

Background. Matrix metalloproteinase-7 (MMP-7) is a member of the family of matrix-degrading metalloproteinases (MMPs) that are considered to contribute to cancer invasion and metastasis. One of the gene products that the authors have isolated by a cDNA subtraction of human gastric cancer minus normal gastric mucosa is MMP-7. The purpose of this study was to examine the expression of MMP-7 mRNA in different stages of human colorectal carcinomas. Methods. A subtracted complementary DNA library was generated from a paired sample of human gastric carcinoma minus normal gastric mucosa. Screening of the library clones determined that MMP-7 mRNA was overexpressed. The complementary DNA insert was then used as a probe to evaluate the expression in a larger number of surgical samples of human colorectal carcinomas by Northern hybridization. Results. The mRNA signal was greater in the colorectal carcinoma than in paired adjacent normal colonic or rectal mucosa in 39 of 47 cases. The expression of MMP-7 mRNA in tumor tissues increased with increasing Dukes' stage (P < 0.05). The MMP-7 mRNA expression was greatest in the metastatic liver lesions. Conclusions. The findings imply that MMP-7 mRNA is overexpressed in human colorectal carcinomas and that MMP-7 may prove useful as a marker of biologic aggressiveness. Cancer 1995;75:1516-9.