The Pathological Significance and Prognostic Roles of Thrombospondin-1, and -2, and 4N1K-peptide in Bladder Cancer.

Abstract

Thrombospondins (TSPs) play a role as inhibitors of angiogenesis under various pathological conditions. The aim of the study was to evaluate the pathological significance and prognostic role of the 4N1K-peptide (KRFYVVMWKK), which is derived from TSP-1 and -2, in bladder cancer. Two-hundred and six bladder cancer tissues were examined for expression of TSP-1, TSP-2, and 4N1K-peptide by immunohistochemistry. Cancer cell proliferation, apoptosis, angiogenesis and matrix metalloproteinase (MMP)-9 immunoreactivity were also examined. Expression of TSP-2 and 4N1K-peptide was negatively associated with T stage, metastasis, and grade. TSP-2 expression was negatively associated with cancer cell proliferation and MMP-9 expression, whereas 4N1K-peptide was significantly associated with apoptosis, angiogenesis, and MMP-9 expression. Multivariate analysis showed that 4N1K-peptide expression was a significant predictor of metastasis (hazard ratio=3.90, p=0.002). TSP-2 and 4N1K peptide played important roles in malignant aggressiveness and progression of bladder cancer via complex mechanisms involving cell proliferation, apoptosis, angiogenesis, and MMP-9.