Gene expression profiling for circPETH overexpression and knockout
Metabolic reprogramming fuels cancer cell metastasis and remodels immunosuppressive tumor microenvironment (TME). We report here that a circRNA packaged by extracellular vesicles (EVs) from tumor-associated macrophages (TAMs) to hepatocellular carcinoma (HCC) cells, circPETH, facilitates glycolysis and metastasis of HCC cells. Mechanistically, circPETH-147aa, encoded by circPETH in m6A-driven manner, promotes the PKM2-catalyzed ALDOA-S36 phosphorylation via MEG pocket. Furthermore, circPETH-147aa impairs anti-HCC immunity by elevating the HuR-dependent SLC43A2-mRNA stability and stimulating the deficiency of methionine and leucine in cytotoxic CD8+ T cells. Importantly, we successfully identified a novel small molecule, Norathyriol, by virtual and experimental screening as an effective inhibitor targeting MEG pocket on circPETH-147aa surface. Norathyriol reverses circPETH-147aa-facilitated metabolic and metastatic phenotypes of HCC cells, improves anti-PD1 efficacy and boosts cytotoxic CD8+ T cells function. Our findings determine Norathyriol as a promising anti-HCC agent, and contribute to overcoming the resistance of advanced HCC to immune checkpoint blockades (ICBs) therapies. Overall design: To gain insights into the regulatory mechanism of circPETH in terms of comprehensive gene expression, RNA-sequencing (RNA-seq) was conducted to compare the following two expression profiles: OE-circPETH versus Vector; and circPETH KO versus NTC.