CircACAP2 promotes cell proliferation and migration in lung adenocarcinoma via LASP1-mediated TGF‐β/Smad3 pathway

Abstract Lung adenocarcinoma (LUAD), a common malignant tumor, has led to a great number of deaths around the world. Circular RNAs (circRNAs) have been certified as essential players in the progression of diverse cancers. CircRNA ACAP2 (hsa_circ_0068568) is an oncogene in several cancers. However, the role of circACAP2 in LUAD remains unknown. This study revealed that the expression of circACAP2 was significantly elevated in LUAD tissues and cell lines, especially in the tissues of LUAD patients at advanced stage. Additionally, circACAP2 enhanced cell proliferation, migration, invasion abilities and epithelial-mesenchymal transition (EMT) process in LUAD. Moreover, miR-342-3p interacted with circACAP2 in LUAD cells. Importantly, we found that miR-342-3p targeted LIM and SH3 protein 1 (LASP1), and circACAP2 positively regulated LASP1 expression by competing for miR-342-3p in LUAD. Further, it was confirmed that circACAP2 promoted the malignant behaviors and stimulated the activation of TGF-β/Smad3 pathway in LUAD by modulating the miR-342-3p/LASP1 axis. To conclude, the molecular regulatory mechanism of circACAP2 in LUAD was under discussion in the current study. The findings revealed that circACAP2 facilitated malignant phenotypes in LUAD via the activation of the TGF‐β/Smad3 pathway.