Background: Ameloblastoma is a frequently encountered odontogenic benign tumor characterized by local invasiveness and high risk of recurrence. Matrix metalloproteinase (MMP)-2 can degrade type IV collagen, one of the major components in the basement membrane, resulting in the promotion of tumor invasion, whereas it is under the influence of an activator, membrane type 1-MMP-14 and the tissue inhibitor of metalloproteases (TIMP)-2. The aim of this study was to investigate combinatorial role played by MMP-2, TIMP-2 and MMP-14 in ameloblastoma.
Methods: Transcriptional expression of MMP-2, TIMP-2 and MMP-14 in tissue extracts of 42 ameloblastomas and 10 dental follicles was detected using reverse transcription-polymerase chain reaction, and compared difference in clinical type and local recurrence of ameloblastoma.
Results: MMP-2, TIMP-2 and MMP-14 mRNA were detected in all investigated ameloblastoma tissues. While MMP-2 mRNA was only expressed in eight of 10 odontotheca tissues and TIMP- 2 and MMP-14 were not found in all odontotheca tissues. The mRNA expression of MMP-2, TIMP-2 and MMP-14 were significantly higher in ameloblastoma tissues than in odontotheca tissues. The mRNA levels of TIMP-2 and MMP-14 were significantly higher in recurrent and solid/multicystic ameloblastoma tissues than in primary and unicystic ameloblastoma tissues respectively.
Conclusions: Of the MMP-2/TIMP-2/MMP-14 complex, a high expression of MMP-2, TIMP-2 and MMP-14 mRNA levels may contribute to the local invasive characteristics of ameloblastoma, whereas the local invasive capacity of ameloblastoma is more likely related to a high transcriptional levels of TIMP-2 and MMP-14.