Expression of matrix metalloproteinase -7 mRNA in human colorectal neoplasms

Objective: To investigate the correlation of MMP 7 mRNA expression with the progression of colorectal carcinoma. Methods: RT PCR technique was used to measure the expression of MMP 7 mRNA in clinical specimens. Results: MMP 7 mRNA was observed in 97.4%(37/38)colorectal cancers and in 1 liver metastatic tumor, while it was almost undetectable in the normal mucosas. The level of MMP 7 mRNA increased in parallel with Dukes stage of colorectal carcinoma ( P 0.01); as: Dukes A, 0.28±0.08; Dukes B, 0.54±0.17; Dukes C, 0.55±0.09; Dukes D, 0.73±0.06. MMP 7 mRNA was also observed in 5 cases with colorectal adenomas, but its expression level was lower than that of colorectal carcinomas. All 13 histologically positive lymph nodes were positive for MMP 7 mRNA, while of 12 histologically negative lymph nodes, 6 were positive and the other 6 were negative. When histological re examination was performed on 12 histologically negative lymph nodes, micrometastases were detected in 3 MMP 7 positive lymph nodes. Conclusion: The overexpression of MMP 7 may play an important role in infiltration and metastasis of colorectal neoplasms. RT PCR assay for MMP 7 mRNA is a sensitive method for detecting lymph node micrometastases in patients with colorectal carcinoma.