Overexpression of matrix metalloproteinase-12 (MMP-12) correlates with poor prognosis of hepatocellular carcinoma.

Tumour recurrence and metastasis are pressing issues of hepatocellular carcinoma (HCC) patients who receive surgical treatments. Matrix metalloproteinase-12 (MMP-12), previously identified from our animal model, is involved in tumour invasiveness of rat hepatoma. We aimed to investigate the significance and prognostic value of MMP-12 expression in human HCC. MMP-12 mRNA level of 139 pairs of tumour and non-tumour liver tissues of HCC patients after hepatectomy were investigated by quantitative real-time RT-PCR. MMP-12 mRNA was significantly elevated in tumour liver tissues of HCC patients compared to non-tumour and normal liver tissues. By comparing paired tumour and non-tumour liver tissues, MMP-12 mRNA was overexpressed in 58% of tumour tissue of HCC patients. Overexpression of MMP-12 mRNA was significantly correlated with presence of venous infiltration (p=0.004), high serum AFP level (p=0.012), early tumour recurrence (p=0.018) and poor overall survival (p=0.02) of HCC patients. Moreover, MMP-12 mRNA was an independent factor in predicting the 1- and 3-year overall survival of HCC patients after hepatectomy. Our data demonstrated that MMP-12 mRNA may be a valuable prognostic marker for both overall survival and tumour recurrence of HCC patients after liver resection.