Many investigators have demonstrated that the family of matrix metalloproteinases (MMP) are important in the degradation of extracellular matrices, which facilitates cancer cell invasion and metastasis. In renal cell carcinoma (RCC), expression of both MMP 2 and 9 have been correlated with prognosis and thought to be important molecular markers of metastatic progression.
Here, Miyata and colleagues examine the expression of MMP 10 as a marker of prognosis in RCC.Immunohistochemistry was utilized in 103 specimens of clear cell RCC, collected over a 7 year period, to examine MMP 10 expression. Positive staining was identified in 43.7% of the samples and was primarily identified in the cell cytoplasm. Interestingly, the authors reported anecdotal evidence of increased expression of MMP 10 in the few samples of sarcomatoid differentiation that they tested. Over expression of MMP 10 correlated with increased tumor grade (p= 0.006), increased pT stage (p<0.001), and increased tumor microvessel density (p=0.22). In multivariate analysis, MMP 10 expression was an independent predictor of advanced pT stage, but was not predictive of death from RCC in this study group. Over expression of MMP10 also did not correlate with the presence of metastatic disease.Like MMP 9 and 2, over expression of MMP 10 appears to be associated with a worse prognosis and more advanced stage disease in RCC. Further studies are needed to elucidate the exact function of the family of MMP's in the biology of RCC progression and metastasis.(Source: European Journal of Urology : Nagasaki University : May 2007.)