Gene expression profiling of CD8+ T cells in the Norathyriol versus PBS-treated co-culture system

Metabolic reprogramming fuels cancer cell metastasis and remodels the immunosuppressive tumor microenvironment (TME). We report here that a circRNA, circPETH, packaged by extracellular vesicles (EVs) from tumor-associated macrophages (TAMs) to hepatocellular carcinoma (HCC) cells, facilitates glycolysis and metastasis of recipient HCC cells. Mechanistically, circPETH-147aa, encoded by circPETH in a m6A-driven manner, promotes PKM2-catalyzed ALDOA-S36 phosphorylation via MEG pocket. Furthermore, circPETH-147aa impairs anti-HCC immunity by elevating HuR-dependent SLC43A2 mRNA stability and driving methionine and leucine deficiency in cytotoxic CD8+ T cells. Importantly, by virtual and experimental screening, we found that the novel small-molecule Norathyriol was an effective inhibitor that targets the MEG pocket on circPETH-147aa surface. Norathyriol reverses circPETH-147aa-facilitated acquisition of metabolic and metastatic phenotypes for HCC cells, increases anti-PD1 efficacy and boosts cytotoxic CD8+ T-cell function. Our findings determine Norathyriol as a promising anti-HCC agent that contributes to the attenuation of advanced HCC resistance to immune checkpoint blocker (ICB) therapies.