CDC25B, Ki-67, and p53 expressions in reactive gliosis and astrocytomas.

Purpose: To investigate the expression of CDC25B, which is a member of the cyclin-dependent kinase activating phosphatase family, in diffuse astrocytoma (DA), anaplastic astrocytoma (AA), glioblastoma multiforme (GBM), pilocytic astrocytoma (PA) and reactive gliosis (RG). Also, to study the relationship of the expression level of CDC25B with clinical parameters and with p53 and Ki-67 proliferation index (PI).

Methods: Tissues were collected from 36 cases diagnosed with astrocytoma (10 DA, 6 AA, 20 GBM), 10 PA, 10 RG and 10 normal brain tissues for controlling purposes. The sections were immunohistochemically stained with CDC25B, Ki-67 and p53. For each marker, 1000 tumor cells were counted and the ratio of positive tumor cells was calculated.

Results: The average CDC2B staining index (CSI) was 0.6% in PA, 0.4% in DA , 7.7% in AA and 25.5% in GBM. The increase of CSI in parallel with the increase of WHO grade was significant (p=0.001). No expressions were identified in RG and normal brain. There was also significant relationship between the tumor size and CSI (p=0.027) and also between Ki-67 PI and CSI (p=0.001). Among the groups with low and high CSI in astrocytoma cases, the disease free survival (DFS) was significantly higher in the low CSI group (p=0.0001).

Conclusions: Positive expression of CDC25B in astrocytoma affects the prognosis in an adverse manner. CSI can be used as a diagnostic method and CDC25B may be a possible target molecule for treatment.