Significance of p53 and CD31 in astrogliomas

Astrogliomas are the most common primary brain tumor. Its progression is the result of activation of oncogenes, inactivation of tumor suppressor genes (TSGs), and expression of various growth factors. The angiogenesis and p53 in astrogliomas play an important role in its grading, treatment strategies, and hence its clinical outcome.

To analyze the frequency of presentation and the possible co-expression of p53 and angiogenesis marker (CD31) and their clinical implications in astrogliomas.

This retrograde study included 45 cases with astrocytomas in the form of paraffin blocks. Sections were stained with hematoxylin and eosin to determine the type and histological grade according to WHO (2007) classification of CNS tumors. Immunostaining was done using anti p53 and CD31 and the results were measured as labeling index (LI) using image analyzer system CAS-200.

Both p53 and CD31 expressions were correlated well with the histopathological grades of different subtypes of astrogliomas with good discrimination between low and high grades. Overall, a highly significant statistical correlation was observed between the grades of astrocytomas and the p53 and CD31 labeling indices. The expressions of p53 and CD31 were markedly increased in glioblastoma multiforme (GBM) with mean values (59.7 +/- 13.5) (P = 0.0001) and (40.7 +/- 8.9) (P = 0.001), respectively. Obviously, these observations demonstrate that the co-expression and increased levels of p53 and CD31 in astrogliomas are increasing as the tumor grade is increasing.

The estimation of p53 and CD31 could be used as good tools to assess the grade, prognosis, and aggressiveness of the astroglial tumors. Thus, the two markers can be used as adjunct to the diagnosis and stratification of the high grade from the low-grade intrinsic brain astrogliomas.