Targeting autophagy-related protein kinases for potential therapeutic purpose

Autophagy,defined as a scavenging process of protein aggregates and damaged organelles mediated by lysosomes,plays a significant role in the quality control of macromolecules and organelles.Since protein kinases are integral to the autophagy process,it is critically important to understand the role of kinases in autophagic regulation.At present,intervention of autophagic processes by small-molecule modulators targeting specific kinases has becoming a reasonable and prevalent strategy for treating several varieties of human disease,especially cancer.In this review,we describe the role of some autophagy-related kinase targets and kinase-mediated phosphorylation mechanisms in autophagy regulation.We also summarize the small-molecule kinase inhibitors/activators of these targets,highlighting the opportunities of these new therapeutic agents.

Drug discovery by targeting the protein–protein interactions involved in autophagy

Autophagy is a cellular process in which proteins and organelles are engulfed in autophagosomal vesicles and transported to the lysosome/vacuole for degradation.Protein–protein interactions(PPIs)play a crucial role at many stages of autophagy,which present formidable but attainable targets for autophagy regulation.Moreover,selective regulation of PPIs tends to have a lower risk in causing undesired off-target effects in the context of a complicated biological network.Thus,small-molecule regulators,including peptides and peptidomimetics,targeting the critical PPIs involved in autophagy provide a new opportunity for innovative drug discovery.This article provides general background knowledge of the critical PPIs involved in autophagy and reviews a range of successful attempts on discovering regulators targeting those PPIs.Successful strategies and existing limitations in this field are also discussed.

Discovery of a novel sodium taurocholate cotransporting polypeptide(NTCP) inhibitor: Design, synthesis, and anti-proliferative activities

Sodium taurocholate cotransporting polypeptide(NTCP)is identified as the functional receptor for HBV entry,which is responsible for upregulated HBV transcription in the HBV life cycle.Besides,NTCP is also implicated in the progression of HBV-induced hepatocellular carcinoma(HCC).Thereby,NTCP-targeting entry inhibitors are proposed to suppress HBV infection and replication in HBV-induced hepatoma therapy.Herein,we integrated in silico screening and chemical synthesis to obtain a small-molecule NTCP inhibitor B7,which exhibited moderate anti-proliferative activities against HepG2 cells and anti-HBV activity in vitro.Additionally,CETSA assay,molecular docking,and MD simulation validated that B7 could bind to NTCP.Furthermore,western blot analysis demonstrated that B7 induced apoptosis with an increased expression of Bax and caspase 3 cleaving as well as a decreasing expression of Bcl-2 in HepG2 cells.Taken together,our study identified B7 as a novel NTCP inhibitor with anti-proliferation activities which might provide a new opportunity for HCC therapy.