Hsa_circ_0080608 Attenuates Lung Cancer Progression by Functioning as a Competitive Endogenous RNA to Regulate the miR-661/ADRA1A Pathway.

Circular RNAs (circRNAs) participate in the progression of human cancers and have been broadly elucidated. Here, we aimed to elucidate the roles and functional mechanisms of hsa_circ_0080608 (circ_0080608) in lung cancer. Quantitative real-time PCR (qPCR) was performed to assess the mRNA expression levels of circ_0080608, miR-661, and adrenoceptor alpha 1A (ADRA1A). Western blotting was performed to measure ADRA1A protein levels. CCK-8, colony formation, and Transwell assays were performed to determine the effect of circ_0080608 on cell proliferation and migration. Animal models were used to assess how circ_0080608 influences tumor progression in vivo. The binding relationships of miR-661's with circ_0080608 and ADRA1A was confirmed using dual-luciferase reporter and RIP assays. Circ_0080608 exhibited relatively low expression in lung cancer samples and cells. Lung cancer cells overexpressing circ_0080608 exhibited reduced migratory and proliferative abilities. Additionally, circ_0080608 binds to miR-661 and operates as a competing endogenous RNA (ceRNA) and shares a miR-661 binding site with the 3' UTR of ADRA1A. Furthermore, circ_0080608 inversely regulates miR-661 expression, consequently restraining the aggressive behavior of lung cancer cells. Lung cancer cells overexpressing ADRA1A also exhibit repressed migratory and proliferative abilities. However, reintroduction of miR-661 led to a decline in ADRA1A expression, thereby attenuating the functional effects of ADRA1A. Circ_0080608 impedes lung cancer progression by regulating the miR-661/ADRA1A pathway. Our findings provide new insights into the progression of lung cancer.