Kuwanon E sensitizes hepatocellular carcinoma cells to disulfidptosis via MTOR-mediated autophagy blockade.
TL;DR
Kuwanon E (KE) is identified as the most potent sensitizer of disulfidptosis in HCC cells and is established as a functional disulfidptosis-sensitizing agent from a natural source, providing a compelling mechanistic rationale for targeting disulfidptosis to overcome metabolic and autophagic resistance in HCC.
Abstract
Disulfidptosis, a recently identified form of regulated cell death driven by toxic intracellular disulfide accumulation and subsequent collapse of the actin cytoskeleton, represents a promising therapeutic vulnerability in hepatocellular carcinoma (HCC), particularly for tumors exhibiting metabolic reprogramming and resistance to conventional apoptosis-based therapies. In this study, we screened eleven representative bioactive constituents derived from Cortex Mori, including stilbenoids, flavonoids, coumarins, and phenolic acids, under glucose deprivation conditions that trigger disulfidptosis, and identified Kuwanon E (KE) as the most potent sensitizer of disulfidptosis in HCC cells. Integrative network pharmacology, RNA sequencing, and untargeted metabolomics revealed that KE preferentially targets the MTOR signaling pathway and autophagic flux. Mechanistically, KE significantly prolonged the half-life of MTOR protein without altering its mRNA expression, leading to MTOR accumulation. This was accompanied by a blockade of autophagic flux at the autophagosome-to-lysosome fusion step, as evidenced by increased p62 and LC3-II protein levels and accumulation of mRFP-GFP-LC3 puncta. This autophagic stagnation resulted in profound depletion of glutathione (GSH) and NADPH, shifting the redox balance toward disulfide formation and promoting non-reducible cross-linking of key cytoskeletal proteins FLNA and DREBRIN, ultimately leading to actin network collapse and cell death. Importantly, co-treatment with the MTOR inhibitor/autophagy inhibitor activator rapamycin or exogenous GSH supplementation effectively rescued KE-mediated disulfidptosis sensitization, confirming the functional centrality of MTOR signaling and GSH metabolism. These findings establish KE as a functional disulfidptosis-sensitizing agent from a natural source and provide a compelling mechanistic rationale for targeting disulfidptosis to overcome metabolic and autophagic resistance in HCC.