Overexpression of MT3-MMP in hepatocellular carcinoma correlates with capsular invasion

BACKGROUND/AIMS: Extracellular matrix-degrading matrix metalloproteinases (MMPs) are invariably up-regulated in epithelial cancers and are key agonists of angiogenesis, invasion and metastasis. Recent studies have shown high levels of various MMPs, including MT1-MMP, MMP-1, MMP-2 and MMP-9, and their involvement in tumor progression in human hepatocellular carcinoma (HCC). However, the expression and role of MT3-MMP in HCC remains unclear. METHODOLOGY: We examined the immunohistochemical expression of MT3-MMP in surgically resected HCCs (n=58), hepatitis C virus (HCV) and hepatitis B virus (HBV)-related chronic hepatitis (n=34) and cirrhosis (n=24). RESULTS: MT3-MMP expression was observed in all non-cancerous liver tissues. In HCCs, 52% (30/58) of patients showed high MT3-MMP expression while the remaining 48% (28/58) of patients showed low expression. A clinicopathological survey demonstrated a significant correlation between high MT3-MMP expression and capsular invasion of carcinoma (p = 0.034) although there was no correlation between high MT3-MMP expression in HCC and overall survival or disease-free survival. CONCLUSIONS: MT3-MMP was expressed not only in chronic hepatitis and liver cirrhosis, but also in HCC, and high MT3-MMP expression correlated significantly with capsular invasion of carcinoma.