A quantitative histological study of the expression of Snail and Cytokeratin 18 in benign prostatic hyperplasia and prostatic adenocarcinoma

The purpose of this study is to quantify from a histological point of view, the expression of Snail, both nuclear and cytoplasmic, correlating it with cytokeratin 18 immunoreactivity in normal prostate, benign prostate hyperplasia, and prostate cancer by estimates of integrated optical density per unit area in arbitrary units of uncalibrated optical density per µm2. These estimates will be made both globally and locally to verify the heterogeneity of these markers. Linear regression was applied to investigate the correlation between the expression of Snail and the expression of cytokeratin 18 in the study groups. Discriminant analysis performed to classify the cases in the study groups was also applied using Snail and cytokeratin 18 measurements as classifying variables. In all cases, Snail's immunoexpression is heterogeneous with local variations. In cancer, the expression of Snail is abundant at the nuclei, while in normal and hyperplastic tissue Snail is mainly cytoplasmic, which may indicate that in these situations, Snail predominates in an inactive form. The expression of Snail is negatively correlated with that of the epithelial marker cytokeratin 18; this could be correlated with mesenchymal epithelium transition developed in the cancer progression. Snail and cytokeratin 18 immunoexpression were able to discriminate between normal, hyperplastic, and malignant prostate tissues.