EIF4A3-regulated hsa_circ_0001445 can inhibit the progression of laryngeal squamous cell carcinoma via hsa-miR-432-5p-dependent up-regulation of RGMA expression

Laryngeal squamous cell carcinoma (LSCC) is a common malignant tumor in the head and neck, the 5-year relative survival rate of patients diagnosed with laryngeal cancer was estimated to be 61% from 2012 to 2018. An increasing number of studies have shown that circular RNAs (circRNAs) play a key role in the occurrence and development of cancer and may function as cancer biomarkers and new therapeutic targets. At present, the research on the relationship between circRNAs and LSCC is still in its infancy and needs further exploration. In this study, we found a circRNA (hsa_circ_0001445) associated with LSCC based on bioinformatics analysis. Quantitative real-time polymerase chain reaction (qRT-PCR) assay indicated that the expression of hsa_circ_0001445 was down-regulated in LSCC tissues and cell lines. Notably, the expression of hsa_circ_0001445 was negatively correlated with aggressive clinicopathological features and poor prognosis. Then, functional experiments found that overexpression of hsa_circ_0001445 inhibited the proliferation, migration and invasion of LSCC cells and tumor growth in vivo. Mechanistically, RNA immunoprecipitation (RIP), biotin-labeled probe pull-down, luciferase reporter assay and western blot experiments were employed and found that EIF4A3 reduced the expression of hsa_circ_0001445, and the direct binding of hsa_circ_0001445 to hsa-miR-432-5p attenuated the inhibitory effect of hsa-miR-432-5p on RGMA. In summary, our research suggests that hsa_circ_0001445 may be used as a potential prognostic biomarker and therapeutic target for LSCC.