Expression and significance of MMP2 and HIF-1α in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a serious threat to human health. HCC is a malignant tumor and its invasion and metastasis are the result of multigene interactions. Matrix metalloproteinase-2 (MMP-2) is capable of degrading the majority of components of the extracellular matrix and is regarded to closely correlate with tumor invasion and metastasis. Furthermore, the hypoxia-inducible factor 1α (HIF-1α) is an important transcription factor, which is closely associated with the process of tumor growth. The aim of the present study was to investigate the expression of MMP2 and HIF-1α) in HCC, and the relationship between MMP2/HIF-1α protein expression and the clinical/pathological characteristics of HCC. The mRNA levels of MMP2 and HIF-1α were detected in 32 cases of HCC and the corresponding normal adjacent tissues with fluorescence-based quantitative polymerase chain reaction (qPCR). The protein expression of MMP2 and HIF-1α was assessed in 45 HCC cases and 33 cases of corresponding normal adjacent tissue, using immunohistochemical methods. The association between MMP2/HIF-1α and pathological features of HCC, and the correlation between MMP2 and HIF-1α were analyzed. The Kaplan-Meier method was used to assess the impact of MMP2 and HIF-1α expression on survival. The fluorescence-based qPCR demonstrated that MMP2 and HIF-1α mRNA expression levels in the HCC tissues were 0.84±0.17 and 0.87±0.11, respectively, which were significantly higher than those in the adjacent normal tissues (0.70±0.13 and 0.68±0.13, respectively; P<0.05). Immunohistochemical analysis revealed that MMP2 and HIF-1α protein expression in the HCC tissues was 63.1 and 70.8%, respectively, which was also higher than that in the adjacent normal tissues (34.2 and 36.8%, respectively). There was no significant correlation between the expression of MMP2 or HIF-1α protein and the age or gender of patients with HCC (P>0.05). However, there was significant correlation between MMP2 or HIF-1α protein expression and tumor size, metastasis, presence of a capsule and clinical TNM staging of HCC. Their expression also had a significant effect on patient survival time. In conclusion, MMP2 and HIF-1α are overexpressed in HCC, and the MMP2 signaling pathway may promote the development of HCC together with HIF-1α.