Hypoxia-induced autophagy in hepatocellular carcinoma and anticancer therapy

Abstract

Autophagy is a genetically programmed dynamic process for the lysosomal degradation and recycling of bulk cytoplasmic contents, abnormal proteins, and damaged organelles. Along with cellular homeostasis maintenance, autophagy plays a fundamental role in cancer as tumor cells activate autophagy under stressful conditions such as hypoxia, nutrient derivation, and anticancer therapy. Increasing reports suggest the protective role of autophagy in hepatocellular carcinoma (HCC). Despite recent developments in HCC anticancer treatment, the overall patient survival remains poor. Tumor hypoxia, a common characteristic of most solid tumors like HCC is correlated with poor prognosis for patients partly because hypoxia promotes resistance to cancer therapy. Hypoxia preferentially selects apoptosis-resistant cells and activates autophagy as a survival mechanism leading to malignant and aggressive phenotype. In this review, we summarized the molecules involved in hypoxia-induced autophagy for HCC progression and anticancer therapy resistance. In addition, the molecular pathways involved in hypoxia-induced autophagy were provided. We also focused on some recent researches between hypoxia-induced autophagy and microRNAs in HCC. We believe understanding the novel function of hypoxia-regulated autophagy may coin new targets for the betterment of HCC treatment and improved clinical outcomes.