hsa_circ_0000264 promotes tumor progression via the hsa-let-7b-5p/HMGA2 axis in head and neck squamous cell carcinoma

Objective Circular RNAs (CircRNAs) are involved in various tumors. However, their role in head and neck squamous cell carcinoma (HNSCC) is unknown. CircRNA sequencing data showed that hsa_circ_0000264 is significantly upregulated in HNSCC tissues. In this study, we aimed to investigate the role of hsa_circ_0000264 in HNSCC and elucidate its underlying regulation mechanism. Materials and Methods RNase R treatment was performed to confirm the loop structure of hsa_circ_0000264. Fluorescence in situ hybridization was performed to show the subcellular localization of hsa_circ_0000264. We then performed wound healing assay, Transwell assay, Western blot, and in vivo experiments to determine the effect of alterations in hsa_circ_0000264 expression. We performed RNA pull-down and dual luciferase reporter assay to identify and confirm the binding sites in RNAs. Results hsa_circ_0000264 was upregulated in HNSCC tissues and cells, and its loop structure was confirmed. Knockdown of hsa_circ_0000264 inhibited the migration, invasion, and epithelial-to-mesenchymal transition of HNSCC cells in vivo and in vitro. Mechanistically, hsa_circ_000026 upregulation can upregulate the expression of high mobility group AT-hook 2 (HMGA2) by sponging hsa-let-7b-5p, which in turn promotes HNSCC progression. Conclusion Our results showed that hsa_circ_0000264 promotes HNSCC progression via the hsa-let-7b-5p/HMGA2 axis, and hsa_circ_0000264 can serve as a potential target for HNSCC treatment.