Expression of cyclin A and p27Kip1 in meningiomas

To investigate the cell cycle associated proteins involved in the growth of meningiomas, we studied the expression of cyclin A and p27(Kipl) in 52 meningiomas by immunohistochemical method. A cyclin A labeling index (LI) increased with histological grade. The mean cyclin A LI follows: anaplastic type, 8.53+/-3.73%; atypical type, 5.84+/-2.65%; benign type, 0.92+/-0.24% A positive linear correlation between cyclin A LI and Ki-67 LI was found (R-2=0.87). p27(Kipl) expression was diffuse and strong in benign type, whereas p27(Kipl) expression was decreased in atypical and anaplastic type. The mean p27(Kipl) LI follows: anaplastic type, 52.3+/-14.8%; atypical type, 66.8+/-9.8%; benign type, 78.8+/-8.9%. High cyclin A LI and low p27(Kipl) LI were correlate with tumor recurrence. Our results suggest that cyclin A and p27(Kipl) may be involved in the growth control of meningiomas.