A Comparative Study of PCNA(Proliferating Cell Nuclear Antigen) and AgNORs(Argyrophilic Nucleolar Organizer Regions) in Malignancy of Brain Tumors

ABSTRACT

The authors studied the expression of proliferating cell nuclear antigen (PCNA) and the number of argyrophilic nucleolar organizer regions (AgNORs) in 94 cases of various brain tumors and in 5 cases of normal brains. PCN was recognized immunohistochemically in paraffin sections by the monoclonal antibody PC-10. AgNORs could be demonstrated using the silver impregnation method. The PCNA index was not significantly different from the histological grading of glioma(glioblastoma multiforme 41.40+/-29.14%, anaplastic astrocytoma 35.00+/-41.02%, and low grade astrocytoma 22.37+/-30.85%) and there was a wide range of staining even in the same tissue section. However, the AgNORs count per cell correlated well with the pathologic grading of glioma (glioblastoma multiforme 3.19+/-0.71, anaplastic astrocytoma 2.06+/-0.16, and low grade astrocytoma 1.27+/-0.29) with statistical significance. In meningiomas, AgNORs were useful to differentiate benign meningiomas(1.25+/-0.19) and malignant meningiomas(1.78+/-0.35) The authors suggest that the AgNORs count is a faster, less expensive, and a more predictive method in the malignancy of brain tumors than the PCNA immunochemistry expression.