Objective: To detect protein expression of MMPs and TIMPs in various salivary gland neoplasms and to investigate their roles in invasion and metastasis of the malignant salivary gland tumors.
Methods: Immunohistochemistry and Gelatin zymography analyses for MMP-2, MMP-9, MT1-MMP, TIMP-1 and TIMP-2 were performed in 26 malignant and 28 benign salivary gland tumors.
Results: The expression of MMP-2 and MMP-9 was significantly higher in carcinomas than in adenomas (P < 0.05). The MMP-2/TIMP-1 and MMP-2/TIMP-2 was also significantly higher in carcinomas than in adenomas (P < 0.05). There was a cooperated effect among MMP-2, MT1-MMP and TIMP-2. The expression of active MMP-2, proMMP-9 and active MMP-9 was significantly higher in malignant tumors than in benign tumors (P < 0.05).
Conclusion: MMP-2 and MMP-9 may play important roles in invasion of malignant salivary gland tumors. A disturbed balance between MMP-2, MMP-9, TIMP-1 and TIMP-2 in malignant salivary gland tumors was detected. It was the absolute increase of MMP-2 and MMP-9 to induce the unbalance.