Overexpression of matrix metalloproteinase 9 in tumor epithelial cells correlates with colorectal cancer metastasis.

Colorectal cancer mortality largely reflects metastasis, the spread of the disease to distant organs. Matrix metalloproteinase 9 (MMP-9) is a key regulator of metastasis and a target for anticancer strategies in colon cancer. Here, the overexpression of MMP-9 in pure tumor epithelial, but nor stromal, cell populations was associated with metastatic progression of colorectal cancer, as defined by reverse transcriptase-polymerase chain reaction (qRT-PCR) and confirmed by immunostaining. Thus, cancer cell MMP-9 represents a novel, selective prognostic and predictive factor that may be exploited for more effective disease stage stratification and therapeutic regimen selection in patients with colorectal cancer.