Nuclear overexpression of urocortin discriminates primary brain tumors from reactive gliosis

The role of urocortin (UCN) is still ambiguous in human cancers. We tested the hypothesis that using UCN expression discriminates reactive gliosis from primary brain tumors (PBTs). Immunohistochemical analysis of UCN was performed in six reactive gliosis and 99 PBTs. The immunostain scores of UCN were calculated as the degree of intensity multiplied by the percentage of expressed tumor cells. Nuclear staining of UCN revealed weak intensity and small portion of positively stained cells in reactive gliosis. However, comparing with non-neoplastic tissues, higher immunostain scores of UCN were identified in each WHO grade of astrocytomas and meningiomas. Finally, neither WHO grade nor overall survival rate did not significantly correlate with UCN expression in astrocytomas and meningiomas. Our findings demonstrate for the first time that the application of UCN might be a novel biomarker for not only discriminating reactive gliosis from PBTs, but also deciding where the clear surgical margin was.