Cytoplasmic expression of P63 in neoplastic and non neoplastic prostatic tissue

ABSTRACT

P63 gene, is one of tumor suppressor genes. In normal and benign prostatic glands, it is found only in basal cells, so p63 helps to differentiate prostate cancer from benign mimicker, as it is expressed mainly in the nuclei of cells of normal and benign lesions. We studied the cytoplasmic mislocalization of p63 in different prostatic lesions as it may have a role in prostatic oncogenesis. Groups of 34 malignant, 26 suspicious and 12 benign prostatic tissue cases were retrieved from pathology department in Assiut university hospital and from other private laboratories. All specimens were immunostained for p63 and p504s. P504s was used to confirm diagnosis of malignancy. Prostatic acinar adenocarcinoma cases compared with normal prostatic tissues and benign prostatic lesions, showed statistically highly significant cytoplasmic staining for p63 [p=0.00002]. The intensity of cytoplasmic expression has high significant correlation with Gleason's score [p=0.000]. Additionally cytoplasmic expression was present in 8/10 high grade prostatic intraepithelial neoplasia [HGPIN] foci within the malignant specimen, with faint intensity. Cytoplasmic staining for p63 was also detected in benign glands within or near malignant foci in 42/44 of malignant cases. The aberrant cytoplasmic p63 expression in malignant foci, PIN and normal benign looking glands within malignant cases and its absence in normal and benign prostatic lesions emphasized the oncogenic role of aberrant genetic expression. Also its expression in benign glands surrounding malignancy may be used as an indicator for nearby malignant lesions or premalignant changes