Comparative Evaluation of p53-protein Expression and Proliferating Indices in Astrocytic Tumors

Kim, Tae Young; Moon, Seung Keun; Kim, Jong Moon

Abstract

Paraffin-embedded surgical specimens from 27 human astrocytic tumors(7 astrocytomas, 10 anaplastic astrocytomas and 10 glioblastomas) were analyzed immunohistochemically for the presence of p53 protein and proliferation markers of proliferating cell nuclear antigen(PCNA), Ki-67 and agyrophilic nucleolar organizer regions (AgNORs). Approximately 33% of total cases were p53-protein positive. The p53-protein positive nuclei were revealed in 5 cases(50%) of glioblastomas, 4 cases(40%) of anaplastic astocytomas. None of the astrocytomas including 2 pilocytic tumors was p53-protein positive. There were no differences between histological types and p53-protein expression(p=0.0593), however, the more malignant histological features appear to be reflected by a greater incidence of p53 accumulation. In comparative evaluation of p53-protein expression and proliferation indices of PCNA, Ki-67 and AgNORs statistical analysis revealed significant correlation between p53 protein expression and Ki-67 labeling indices only(p=0.0177). p53-protein positive astrocytic tumors showed higher Ki-67 labeling index(10.8+/-6.9%) compared to p53-protein negative tumors(5.3+/-4.3%). In conclusion the malignant histological feature of astrocytic tumors may be associated with p53-protein expression, and among proliferation indices Ki-67 labeling index is correlated with p53-protein expression.