TROP2 expression and its correlation with tumor proliferation and angiogenesis in human gliomas

Trophoblast cell surface antigen 2 (TROP2) is a transmembrane glycoprotein which is associated with tumor development and progression in a variety of epithelial carcinomas, while its expression and role in gliomas have not been considered. The aim of the study was to investigate TROP2 expression in malignant gliomas with different World Health Organization (WHO) classification and its correlation with tumor proliferation and angiogenesis. Immuohistochemistry was used to determine TROP2 and Ki-67 expression and microvessel density (MVD) in tumor specimens and normal brain tissues from 69 glioma patients and the relationship between TROP2 and Ki-67 and MVD was investigated. Immunohistochemistry results showed that the TROP2 expression was found in 59 (85.5 %) of the 69 tumor specimens, but no expression in normal brain tissues. Furthermore, TROP2 expression is significantly higher in WHO grade III (P = 0.025) and WHO grade IV (P = 0.011) gliomas than in WHO grade II gliomas. TROP2 expression correlates with Ki-67 (r = 0.676, P = 0.012) and MVD (r = 0.365, P = 0.035), but not with gender or age in human gliomas. These results suggested that the TROP2 correlated with malignancy, proliferation and angiogenesis in human gliomas. This is the first study describing TROP2 expression in gliomas and its proliferation and angiogenesis-related characteristic may serve as a potential therapeutic target for glioma treatment.