Expression of p53 Protein and PCNA in Brain Tumors

ABSTRACT

Formalin-fixed, paraffin-embedded samples of 32 brain tumors(8 meningiomas, 10 astrocytomas(low grade 5, anaplastic 5), 8 glioblastoma multiforme, 6 oligodendrogliomas(low grade 2, anaplastic 3) were investigated by immunocytochemistry with monoclonal antibodies against p53 protein and proliferating cell nuclear antigen(PCNA). Expression of p53 protein was detected in 1 of 5 cases(20%) of low grade astrocytomas, 2 of 5 cases(40%) of anaplastic astrocytoma, 4 of 8 cases(50%) of glioblastoma multiforme and 4 of 4 cases(100%) of malignant oligodendroglioma. All low grade oligodendrogliomas, meningiomas fail to express p53. Expression of PCNA was detected in 3 of 8 cases of meningioma with very low labeling index(0-0.3), 2 of 5 cases of low grade astrocytoma with low labeling index(0-11.3), 3 of 5 cases of anaplastic astrocytoma with middle labeling index(0-28.2), 6 of 8 cases of glioblastoma multiforme and 4 of 4 cases of malignant oligodendroglioma with high labelling index(0-92.3, 7.6-48.1). Expression of PCNA was not detected in low grade oligodendrogliomas. Tumor group with high expression of p53 protein showed increment of PCNA expression. A strong positive correlation between tumor grade and extent of p53 protein and PCNA expression was found(p<0.002) .