Objective: Cyclin D1 is an important nuclear protein required for progression of cells through the G1 phase of the cell cycle. The proliferative potential of meningiomas has been studied using various proliferative markers. However, there have been only few published studies evaluating Cyclin D1 immunoreactivity in meningiomas.
Purpose of the study: The aim of our study was to analyze the Cyclin D1 expression in meningiomas and correlate it both with proliferation markers Ki67 and PCNA, and with meningiomas of WHO grade.
Material and methods: We evaluated immunoreactivity for proliferative markers (Cyclin D1, Ki-67, and PCNA) in a consecutive series of 64 meningioma samples obtained from patients who underwent surgical resection because of cerebral or spinal meningiomas. Immunohistochemical staining with Ki-67, PCNA, and Cyclin D1 was performed using the microwave processing procedure and LSAB+ methodology. The number of positive cells for each antibody has been determined and shown in percentage in relation to 1000 counted cells.
Results: All meningioma samples showed immunostaining for Ki-67, PCNA, and Cyclin D1 antibodies. The Cyclin D1 scores exhibited a close correlation with Ki-67 and PCNA immunostaining (P < 0.01). Some meningiomas (15 cases) showed a combination of nuclear and cytoplasmatic (fine granular) Cyclin D1 immunoreactivity. All proliferative indexes have been in positive correlation with meningioma grade.
Conclusion: Our comparative study of proliferative markers in meningiomas demonstrated Cyclin D1 as a very useful proliferative marker in meningiomas.