Analysis of Matrix Metalloproteinase-9 Expression in Renal Cell Carcinoma

Background: Matrix metalloproteinases (MMPs) are involved in the degradation of the extracellular matrix, which is an important step in tumor invasion and metastasis. A positive correlation between the expression of MMP-9 and aggressive behavior of renal cell carcinomas (RCCs) has been reported. MMP-9 expression in RCCs and adjacent normal kidney tissues were examined in this study. Materials and Methods: Twenty-five patients pathologically diagnosed as clear cell RCCs, from specimens obtained at radical nephrectomy, between May 2003 and December 2004 were enrolled in this study. MMP-9 activity was estimated using gelatin zymography, and quantified using a laser densitometer. The results were compared with clinicopathological characteristics. Results: The expression of MMP-9 was significantly elevated in the RCC compared with non-tumor kidney specimens (p4 cm) or vascular invasion were significantly higher than in those without these clinical manifestations (p