Autophagy paradox: Genetic and epigenetic control of autophagy in cancer progression

Abstract

Autophagy is a highly regulated, evolutionarily conserved process of self-digestion controlled by autophagy-related (ATG) genes. It involves the lysosomal degradation of cargoes, including cytoplasmic organelles, misfolded proteins, and toxic aggregates, to enrich cellular nutrient pools and reduce oxidative stress. In normal cells, basal autophagy occurs to maintain cellular homeostasis, which changes during tumor initiation, progression, and malignant transformation. The alteration in autophagy in cancer remains unclear and under-explored. Research indicates that genetic regulations, such as gene mutations, gene polymorphisms, or epigenetic modifications, including DNA methylation, histone modification, microRNAs (miRNAs), and long non-coding RNAs (lncRNAs), regulate ATGs, orchestrating the fluctuating nature of autophagy in cancer. Many studies describe the paradoxical role of autophagy in cancer, portraying it as a double-edged sword depending on the context, oscillating between promoting cell survival and inducing cell death-the dual roles in preventing tumor initiation and supporting tumor progression place autophagy at the centre of controversy. Recent findings suggest that autophagy is regulated at the intrinsic cellular level and within the tumor microenvironment. Thus, identifying the molecules, mediators, and mechanisms associated with the regulation of autophagy during tumor development, maintenance, therapy resistance, and dormancy could open new research avenues to enhance the efficacy of cancer therapeutics. Furthermore, this review encompasses preclinical studies and clinical trials, highlighting the effectiveness of modulating autophagy in cancer therapy.