Mechanism of circular RNA hsa_circ_0012779 expression in nasopharyngeal carcinoma and its influence on cell biological behavior

Background and purpose: Circular RNA (circRNA) plays an important regulatory role in the development of a variety of tumors. However, the abnormal expression and biological function of circRNA in nasopharyngeal carcinoma remain unclear. This study aimed to explore the effect of hsa_circ_0012779 on the biological behavior of nasopharyngeal carcinoma cells and its molecular mechanism. Methods: The expression of hsa_circ_0012779 in human immortalized nasopharyngeal epithelial cell line NP69 and nasopharyngeal carcinoma cell lines CNE2, 5-8F, HNE1 and SUNE1 was detected by real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR). Cell counting kit-8 (CCK-8) assay and transwell invasion assay were used to detect the effect of hsa_circ_0012779 on the proliferation and invasion ability of nasopharyngeal carcinoma cells. The protein level of ELAV like protein 1 (ELAVL1) in NPC cells with hsa_circ_0012779 knockdown was detected by Western blot. The binding of hsa_circ_0012779 and ELAVL1 was verified by RNA pull-down assay. Results: hsa_circ_0012779 was highly expressed in nasopharyngeal carcinoma tissues and cells. Knockdown hsa_circ_0012779 could inhibit the proliferation and invasion of nasopharyngeal carcinoma cells. hsa_circ_0012779 bound to RNA-binding protein ELAVL1 to promote its expression and colocalization in cytoplasm. In the meanwhile, the effect of knockdown hsa_circ_0012779 on nasopharyngeal carcinoma cells could be reversed by the overexpression of ELAVL1. Conclusion: hsa_circ_0012779 promote the expression of ELAVL1 and thus promote the proliferation and invasion of nasopharyngeal carcinoma, and influence the occurrence and development of nasopharyngeal carcinoma.