Immunohistochemical expression of Beclin-1 and LC3B in benign and borderline ovarian tumors

Abstract

Background Epithelial ovarian tumors account for ⁓90% of ovarian cancers. Recently conducted studies have demonstrated autophagy role in tumor development and progression. Autophagic markers include Beclin-1, essential for autophagosome formation and LC3B, required for the elongation step during autophagy. Aim To investigate Beclin-1 and LC3B expression in benign and borderline epithelial ovarian tumors along with its relation to clinicopathologic parameters. Materials and methods Thirty-six cases of epithelial ovarian neoplasms were subjected to hematoxylin and eosin staining and immunohistochemical staining with Beclin-1 and LC3B. Results Beclin-1 was expressed in the nucleus and/or the cytoplasm of tumor cells. The cytoplasmic expression of Beclin-1 was significantly more frequent in borderline cases compared with benign tumors. High Beclin-1 cytoplasmic expression was significantly associated with tumor size, gross appearance, and tumor histological type. Benign Brenner tumors were the only benign tumors expressing cytoplasmic Beclin-1 localization. Regarding LC3B expression, nuclear and cytoplasmic subcellular localizations were also detected. Cytoplasmic LC3B localization was significantly more frequent in the borderline groups. A significant relation was observed between high cytoplasmic LC3B expression and tumor size, tumor gross appearance, and histological type. The majority of benign Brenner tumors showed a high cytoplasmic LC3B expression. Conclusions The expression of Beclin-1 and LC3B varies in benign versus borderline epithelial ovarian tumors. Cytoplasmic expression is predominant in borderline tumors. Beclin-1 and LC3B cytoplasmic expression is significantly high in small-sized and solid benign tumors. Benign Brenner tumors are the only benign tumors showing cytoplasmic Beclin-1 and LC3B localization.