Clinical significance of autophagic protein LC3 levels and its correlation with XIAP expression in hepatocellular carcinoma

Abstract

Autophagy is a cellular recycling process to enable cell survival in less favorable conditions through degradation of their unnecessary cellular components and utilization of the breakdown components. Autophagy also plays an important role in tumor pathology. In this study, we detected autophagy protein light chain 3 (LC3) and X-linked inhibitor of apoptosis protein (XIAP) in hepatocellular carcinoma (HCC) tissue specimens to assess their role in HCC tumorigenesis and progression. We analyzed expression of LC3, XIAP, and Ki-67 proteins immunohistochemically in surgical specimen of 150 HCC and 136 nontumor hepatic tissues. The levels of LC3 and XIAP proteins were compared between tumor and nontumoral parenchyme. The data showed that LC3 expression was increased in HCC compared with nontumoral parenchyma. LC3 expression was significantly associated with male gender, large tumor size, advanced tumor stages, and worse relapse-free and overall survival (OS). In contrast, XIAP expression was associated with small tumor size, early tumor stage, and better relapse-free and OS. In contrast, XIAP expression was associated with small tumor size, early tumor stage, and better relapse-free and OS. Furthermore, expression of LC3 and XIAP was inversely associated in HCC tissue specimens. In conclusion, increase in autophagic LC3 activity and low XIAP expression could be useful to predict the worse HCC prognosis.