N6-methyladenosine-induced hsa_circ_0011536 acts as a microRNA-576-5p sponge to promote ferroptosis of non-small cell lung cancer cells via transferrin receptor.

Abstract

Lung cancer is the leading cause of death and the most diagnosed cancer worldwide. Non-small cell lung cancer (NSCLC) is the most common type of lung cancer; 85% of lung cancer patients are diagnosed with NSCLC. Though numerous treatments for lung cancer have been developed, the 5-year survival rate of patients with NSCLC remains low. Therefore, it is urgent to explore novel targets for NSCLC treatment. Growing evidence has revealed that circular RNAs (circRNAs) contribute to NSCLC progression. Besides, the data of circRNA microarray (GSE158695) has found that hsa_circ_0011536 is downregulated in NSCLC tissues. Nevertheless, the role of hsa_circ_0011536 in NSCLC remains unknown. In this study, RNA 6-methyladenosine (m6A) modification was detected by methylated RNA immunoprecipitation, the interaction of RNAs was determined using miRNA pulldown and luciferase reporter assay, while ferroptosis was identified by Cell Counting Kit-8 assay, intracellular iron content, and malondialdehyde level. Our findings demonstrated that hsa_circ_0011536 was downregulated in NSCLC cell lines. Mechanism investigation revealed that m6A modification enhanced the back-splicing of pre-ZMYM4 to increase hsa_circ_0011536 expression in A549 and NCI-H1299 cells. Moreover, hsa-miR-576-5p was the target of hsa_circ_0011536, while transferrin receptor (TFRC) was the downstream target of hsa-miR-576-5p in A549 and NCI-H1299 cells. Furthermore, hsa_circ_0011536 elevated TFRC expression by sponging hsa-miR-576-5p in A549 and NCI-H1299 cells, identified by luciferase reporter assay. In addition, hsa_circ_0011536 induced ferroptosis through hsa-miR-576-5p in A549 and NCI-H1299 cells. Therefore, this study revealed that m6A-induced hsa_circ_0011536 elevated TFRC expression to induce ferroptosis by sponging hsa-miR-576-5p in NSCLC. These results might provide novel therapeutic targets for NSCLC treatment.