Expression of bone morphogenetic proteins, the subfamily of the transforming growth factor-beta superfamily, in renal cell carcinoma.

Abstract

We investigated the potential expression of bone morphogenetic proteins, including bone morphogenetic protein-4, 6 and 7, the largest subfamily of the transforming growth factor-beta superfamily, in patients with renal cell carcinoma and identified its potential prognostic value in terms of clinical outcome. Immunohistochemical staining of paraffin sections for bone morphogenetic protein was performed in 185 cases of renal cell carcinoma using a streptavidin-peroxidase procedure. Relationships between bone morphogenetic protein expression, and clinicopathological characteristics and clinical outcome were analyzed. The positive rate of bone morphogenetic protein-4, 6 and 7 expression in renal cell carcinoma was 44.3%, 20.0% and 34.1%, respectively. No statistically significant association was observed between bone morphogenetic protein immunoreactivity and age, Eastern Cooperative Oncology Group performance status and T stage. However, bone morphogenetic protein-4 expression correlated with Fuhrman grade (p = 0.034). The bone morphogenetic protein-7 expression rate was higher in female than in male patients (p = 0.007). The bone morphogenetic protein expression rate in nonclear types including chromophobe or papillary type was higher than that in the clear cell type (each p <0.001). Disease-free survival was higher in patients with bone morphogenetic protein-7 expression than in those without expression (log rank test for trend p = 0.0273). In the current study, the correlation between the expression of bone morphogenetic proteins and histological subtype was found. In addition, our findings suggest that bone morphogenetic protein-7 expression may be considered a new prognostic factor in renal cell carcinoma.