title: Pathological significance and prognostic implications of heme oxygenase 1 expression in non-muscle-invasive bladder cancer: Correlation with cell proliferation, angiogenesis, lymphangiogenesis and expression of VEGFs and COX-2.
abstract: Heme oxygenase 1 (HO-1) is a stress-response protein and its expression is associated with malignant potential and poor prognosis in several types of cancer. The present study investigated the association between HO-1 expression levels and the pathological features, clinical outcomes and other associated factors in patients with non-muscle-invasive bladder cancer (NMIBC). HO-1 expression was evaluated using immunohistochemistry in 147 formalin-fixed tissue specimens. The proliferation index, microvessel density, lymph vessel density and expression of cyclooxygenase (COX)-2 and vascular endothelial growth factor (VEGF)-A, -C, and -D were also investigated. Correlations among variables were analyzed by multivariate analysis. Survival was assessed using Kaplan-Meier survival curves and multivariate statistics. HO-1 expression levels in high-grade and pT1 tumors were significantly higher compared with low-grade and pTa tumors, and were correlated with the proliferation index (P<0.001), lymph vessel density (P=0.021) and COX-2 expression levels (P=0.003). The proliferation index and COX-2 expression levels were also identified as independent contributing factors in multivariate models. Kaplan-Meier survival curves associated HO-1 expression with a poor prognosis in metastasis-free (P=0.047) and cause-specific survival (P=0.017), but not with urinary tract recurrence (P=0.231). Furthermore, HO-1 expression was identified by multivariate analysis to be a significant predictor for cause-specific survival (hazard ratio, 4.08; 95% confidence interval, 1.06-15.66; P=0.004). HO-1 has an important role in the malignant aggressiveness of NMIBC and its expression is associated with cause-specific survival. HO-1-associated activities are regulated by cancer cell proliferation, lymphangiogenesis and COX-2. The results suggest that HO-1 may be a potential therapeutic target and a useful predictive prognostic factor in patients with NMIBC.
authors.affiliation: Department of Urology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8501, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Matsuo
authors.affiliation: Department of Urology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8501, Japan.
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Miyata
authors.affiliation: Department of Urology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8501, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Mitsunari
authors.affiliation: Department of Urology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8501, Japan.
authors.forename: Takuji
authors.initials: T
authors.lastname: Yasuda
authors.affiliation: Department of Urology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8501, Japan.
authors.forename: Kojiro
authors.initials: K
authors.lastname: Ohba
authors.affiliation: Department of Urology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8501, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Sakai
keywords: angiogenesis; cell proliferation; cyclooxygenase-2; heme oxygenase 1; lymphangiogenesis; non-muscle-invasive bladder cancer; vascular endothelial growth factor