P53 Suppressor Gene Tissue Microarray-based Protein Expression Analysis in Meningiomas

Abstract

Background/Aim: Meningiomas represent the main intracranial primary central nervous system (CNS) tumour in adults worldwide. Oncogenes’ over-activation combined with suppressor genes’ silencing affect negatively the biological behavior of these neoplasms. This study aimed to explore the impact of p53 suppressor gene expression in meningiomas’ clinic-pathological features based on a combination of sophisticated techniques. Materials and Methods: Fifty (n=50) meningiomas were included in the study, comprising a broad spectrum of histopathological subtypes. An immunohistochemistry assay was applied on tissue microarray cores followed by digital image analysis. Results: p53 protein over-expression (high staining intensity levels) was observed in 27/50 (54%) cases, whereas the rest (23/50-/46%) demonstrated moderate to low levels of the protein. p53 over-expression was statistically significantly correlated to the mitotic index of the examined cases (p-value=0.001). Interestingly, the atypical/anaplastic group of histotypes demonstrated the strongest p53 expression rates compared to the others (p-value=0.001). Conclusion: p53 over-expression is observed in a broad spectrum of meningiomas. High expression levels lead to an aggressive biological behavior of the malignancy (combined with increased mitotic rates), especially in atypical and anaplastic sub-types that also have a high recurrence rate.