Expression of RACGAP1 in high grade meningiomas: a potential role in cancer progression.

Recently, Rac GTPase-activating protein 1 (RACGAP1) has been shown to have a critical role in various tumors. The aim of the present study was to investigate the expression of RACGAP1 in human meningiomas and to compare these results with the clinicopathological parameters. Thirty-two cases, classified as 13 World Health Organization grade I (40.6 %), 10 grade II (31.3 %) and 9 grade III (28.1 %) primary meningiomas, were selected from our pathological files. Clinico-pathological data, including survival data, were also available. RACGAP1 expression in the meningiomas was measured by real-time quantitative PCR and western blot. Our results showed the level of RACGAP1 expression in grade III meningioma is higher than that of grade I. Higher levels of RACGAP1 mRNA were significantly correlated with tumor size, higher Simpson grade, histological type and clinical course (P < 0.05). Furthermore, the level of RACGAP1 expression mRNA was positively correlated with MIB-1 labeling index in different meningiomas tissue (r(2) = 0.3237, P = 0.0007). Additionally, Kaplan-Meier curves demonstrated a significantly worse survival in patients with high levels of RACGAP1 mRNA (P = 0.008). In conclusion, these findings suggest that RACGAP1 may be used as a potential predictor for tumor proliferative and patient prognosis in meningiomas.