Expression and activity levels of matrix metalloproteinase-7 and in situ localization of caseinolytic activity in colorectal cancer

Matrix metalloproteinase-7 is capable of degrading several ECM and non-ECM molecules and contributes to colorectal cancer progression and metastasis. Here, we examined the significance of MMP-7 in colorectal tumors by detecting active and latent MMP-7 levels and localization of its caseinolytic activity. We investigated expression levels, localization, and proteolytic activity of MMP-7 and local caseinolytic activity in colorectal tumor and paired normal tissues by using real time PCR, casein zymography, immunohistochemistry and in situ casein zymography, respectively. In addition the results were compared with clinicopathological variables. Real time PCR and immunohistochemistry showed that MMP-7 expressions were higher in colorectal tumor tissues than in normal tissues. Also, mRNA expressions of MMP-7 were positively correlated with tumor and pathological stages and negatively correlated with age. Furthermore, MMP-7 mRNA expression had a sensitivity of 81.3% and a specificity of 81.2% at a cut-off value of 0.0006, making it a potential marker for diagnosis of colorectal cancer. According to casein zymography, pro- and active MMP-7 levels were also elevated in tumor tissues. In addition, we assessed local caseinolytic activity using in situ casein zymography. Increased immunoreactivity of MMP-7 and local caseinolytic activity were found in neoplastic cells but not in stromal cells. We emphasized the significant role of MMP-7 in diagnosis and progression and/or development of colorectal cancer. •MMP-7 mRNA and protein expression levels are increased in colorectal cancer.•MMP-7 mRNA expressions are related with late tumor stage and younger patients.•Increased pro and active MMP-7 levels are found in colorectal tumor tissues.•MMP-7 mRNA expression is a potential marker for diagnosis of colorectal adenocarcinoma.•Increment of local caseinolytic activity is detected in colorectal tumor sections.