Expression of Apoptotic Protease Activating Factor-1 in adenoid cystic carcinoma of the salivary glands and its clinicopathological relevance

Abstract

Background/Aim. Apoptotic Protease Activating Factor-1 (Apaf-1) is a key molecule in the intrinsic or mitochondrial pathway of apoptosis. Some pathological conditions such as cancer, stroke, and neurodegenerative diseases, are the result of disregulation in the intrinsic apoptosis pathway. The aim of this study was to analyse the immunohistochemical expression of Apaf-1 in ACC tumor cells of the salivary glands and its correlation with clinicopathological parameters (gender, age, localization, histological type and overall survival). Methods. Formalin-fixed, paraffin-embedded tissues from 50 human ACC of the salivary glands, male and female, average age 58 years, were used for our present study. We used the technique of tissue microarray (TMA blocks). Sections from the TMA mould, 5?m thick, were stained with the streptavidin-biotin immunohistochemical technique using primary antibodies specific for Apaf-1 (Leica Biosystems, Newcastle, UK). Stained tissue sections were analyzed by the light microscope (Olympus type BH-2). Based on the data collected, the database was created in SPSS software v. 22.0 (SPSS Inc., Chicago, ILL, USA), which was used for a further statistical analysis. The statistical data analysis included methods of descriptive and analytical (inferential) statistics. Results. The results of the immunohistochemical analysis of Apaf-1 expression in the samples of patients with ACC of the salivary glands were compared with the clinicopathological parameters of these patients. The immunohistochemical expression of Apaf-1 showed no statistical significance with regard to the patients gender (p=0.552), age (p=0.106), histological tumor type (p=0.654) and localization of ACC in the salivary glands (p=0.486). There was no statistically significant correlation observed between overall survival of ACC patients and Apaf-1 expression in tumor cells (p=0.340,Long-Rank test). Conclusion. With regard to ACC, Apaf-1 expression is not in correlation with clinicopathological parameters (gender, age, localization, histological tumor type, outcome of the disease, and overall survival). Therefore, we believe Apaf-1 cannot be regarded as an independent prognostic factor.