mRNA expression profile of matrix metalloproteinases and their tissue inhibitors in malignant and non-malignant prostatic tissue

Background: Increased expression of matrix metalloproteinases (MMPs) was found in various carcinomas. The aim of this study was to present a comprehensive mRNA expression profile of MMPs in benign and malignant prostatic tissue. Materials and Methods: mRNA expression patterns Of MMP-1, -2, - 7, -9, -11, -14 and their tissue inhibitors (TIMPs) -1, -2 and -3 were studied in cancerous and non-cancerous parts of 17 prostates removed by radical prostatectomy. Competitive reverse transcription PCR was used for quantification of MMP and TIMP mRNA. Results: Both decreased (MMP-2, MMP-11, MMP-14) and a tendency to increased (MMP-9) MMP values in cancerous compared to the non-cancerous samples were observed. Significantly reduced TIMP-2 and TIMP-3 values were remarkable. Relatively strong associations were found among the three TIMPs while only a significant correlation between MMPs was observed between MMP-2 and MMP-7. There were no significant correlations between MMPs and tumor grade and stage and serum prostate-specific antigen. Receiver operation characteristic analyses proved that MMP and TIMP mRNA and their ratios have an insufficient capability to differentiate between cancerous and non-cancerous tissue. The ratios of MMP-9 to all three TIMPs and the ratio of MMP-14 to TIMP-3 were significantly increased. Conclusion: These increased ratios support the view of an imbalance between MMP-9 activity and its inhibitory counterparts in cancerous tissue as an important step in the development of prostate carcinoma and implicate the rationale of using synthetic inhibitors of MMPs as potential therapeutic tools.