Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes which degrade the extracellular matrix or components of the basement membrane. They have essential roles in tumor invasion and metastasis. In bladder cancer, elevated MMP-2 and MMP-9 expression in tumor tissues, correlated with tumor stage, grade or prognosis, were reported in several studies. Moreover, high levels of serum or urine MMP and TIMP were observed in patients with bladder cancer especially in advanced cases. However, the true roles of MMPs and TIMPs in bladder cancer progression are not yet clarified. Here, we discuss the roles and clinical implications of MMPs in bladder cancer
