Tissue inhibitor of metalloproteinases-3 promoter methylation is an independent prognostic factor for bladder cancer.

Abstract

TIMP-3 (tissue inhibitor of metalloproteinases-3) is 1 of 4 members of a family of proteins that were originally classified according to their ability to inhibit matrix metalloproteinases. We analyzed TIMP-3 methylation in 175 urine sediment DNA samples from patients with bladder cancer with well characterized clinicopathological parameters, including patient outcome. We examined urine sediment DNA for aberrant methylation of 9 genes, including TIMP-3, by quantitative fluorogenic real-time polymerase chain reaction. Using an optimal cutoff value by TaqMan(R) quantitation we found that the risk of death was statistically significantly higher in patients with higher TIMP-3 and ARF methylation (HR 1.99, 95% CI 1.12 to 3.27, p = 0.01 and HR 1.66, 95% CI 1.00 to 2.76, p = 0.05, respectively) than in patients without/lower TIMP3 and ARF methylation in urine. A significant correlation was also seen between the risk of death and stage 3 tumor (HR 2.73, 95% CI 1.58 to 4.72, p = 0.003) and metastasis (HR 3.32, 95% CI 1.98 to 5.57, p = 0.0001). Multivariate analysis subsequently revealed that TIMP-3 methylation was an independent prognostic factor for bladder cancer survival with stage and metastasis (p = 0.001 and 0.02, respectively). These results suggest that TIMP-3 promoter methylation could be a clinically applicable marker for bladder cancer progression.