EIF4A3-Induced CircDHTKD1 regulates glycolysis in non-small cell lung cancer via stabilizing PFKL

Lung cancer (LC) is one of the malignancies with the highest incidence and mortality in the world, approximately 85% of which is non-small cell lung cancer (NSCLC). Circular RNAs (circRNAs) exert multiple roles in NSCLC occurrence and development. The sequencing results in previous literature have illustrated that multiple circRNAs exhibit upregulation in NSCLC. We attempted to figure out which circRNA exerts an oncogenic role in NSLCL progression. RT-qPCR evaluated circDHTKD1 level in NSCLC tissue specimens and cells. Reverse transcription as well as RNase R digestion assay evaluated circDHTKD1 circular characterization in NSCLC cells. FISH determined circDHTKD1 subcellular distribution in NSCLC cells. Loss- and gain-of-function assays clarified circDHTKD1 role in NSCLC cell growth, tumour growth and glycolysis. Bioinformatics and RIP and RNA pull-down assessed association of circDHTKD1 with upstream molecule Eukaryotic initiation factor 4A-III (EIF4A3) or downstream molecule phosphofructokinase-1 liver type (PFKL) and insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) in NSCLC cells. Rescue assays assessed regulatory function of PFKL in circDHTKD1-meidated NSCLC cellular phenotypes. CircDHTKD1 exhibited upregulation and stable circular nature in NSCLC cells. EIF4A3 upregulated circDHTKD1 in NSCLC cells. CircDHTKD1 exerted a promoting influence on NSCLC cell malignant phenotypes and tumour growth. CircDHTKD1 exerted a promoting influence on NSCLC glucose metabolism. CircDHTKD1 exerts a promoting influence on NSCLC glucose metabolism through PFKL upregulation. RIP and RNA pull-down showed that circDHTKD1 could bind to IGF2BP, PFKL could bind to IGF2BP2, and circDHTKD1 promoted the binding of PFKL to IGF2BP2. In addition, RT-qPCR showed that IGF2BP2 knockdown promoted PFKL mRNA degradation, suggesting that IGF2BP2 stabilized PFKL in NSCLC cells. CircDHTKD1 exhibits upregulation in NSCLC. We innovatively validate that EIF4A3-triggered circDHTKD1 upregulation facilitates NSCLC glycolysis through recruiting m6A reader IGF2BP2 to stabilize PFKL, which may provide a new direction for seeking targeted therapy plans of NSCLC.