Overexpression of a disintegrin and metalloprotease 8 in human gliomas is implicated in tumor progression and prognosis

A disintegrin and metalloprotease 8 (ADAM8) has been shown to be expressed in various cancer types, and its expression was associated with advanced progression of several tumors. However, little is known about ADAM8 in human gliomas. Therefore, we here evaluated the correlation of ADAM8 expression with the clinicopathological features and prognosis in the patients with gliomas. Immunohistochemistry and western blot were used to investigate the expression of ADAM8 protein, respectively, in 128 patients with gliomas. The expression levels of ADAM8 in glioma tissues were significantly higher (P = 0.002) than those in non-neoplastic brain tissues according to the immunohistochemistry analysis. In addition, a high level of ADAM8 expression was significantly more common in glioma tissues with advanced grade than those with low grade (P = 0.01), which were in line with the results of western blot analysis (P = 0.01). Moreover, the increased expression of ADAM8 was significantly correlated with low Karnofsky performance score (KPS) (P = 0.008), frequent intra-tumor necrosis (P = 0.01), and poor overall survival (P = 0.008). Furthermore, multivariate analysis identified the expression levels of ADAM8 (P = 0.01) and intra-tumor necrosis (P = 0.03) to be independent prognostic factors. These findings suggest for the first time that ADAM8 is frequently overexpressed in human gliomas and is closely associated with poor clinical outcome.