Background:
Matriptase, which is a Type II transmembrane
serine protease, has the potential to activate several
growth factors, including
pro-hepatocyte growth factor (HGF). A
G protein-coupled transmembrane
cell-surface receptor and a
protease-activated receptor 2 (PAR-2) are also required for activation by
matriptase. Activation of PAR-2 has been reported to induce the progression of various
cancers. In a previous study, we evaluated the correlation between upregulation of MET phosphorylation with high
matriptase expression and worse prognosis in patients with muscle invasive
bladder cancer; however, expression of PAR-2,
matriptase and MET in
non-muscle invasive bladder cancer (
NMIBC) has not been evaluated. Materials and methods: We retrospectively analyzed the expression of PAR-2,
matriptase and MET using 55
paraffin-embedded specimens obtained from patients with
NMIBC by immunohistochemistry. Results: MET was significantly expressed in high-grade urothelial
carcinoma (UC) and pathological T1
cancers. High expression of PAR-2 was significantly associated with a worse recurrence rate in
NMIBC. In subgroup analysis, the expression of PAR-2 was also correlated with high recurrence rate in low-grade UC. In addition, expression of
matriptase tended to correlate with worse recurrence rate in high-grade UC. Conclusion: Increased expression of PAR-2 was significantly correlated with worse recurrence rate in patients with
NMIBC. In addition, expression of
matriptase also indicated a tendency toward recurrence in high-grade UC, suggesting an important role of
matriptase-induced PAR-2 activation in
NMIBC.