Targeted regulation of miR-154-5p/Cullin-2 pathway by hsa_circ_0000276 in human papillomavirus type 16 positive cervical cancer cells

Abstract

Abstract Purpose To investigate the role of targeting and silencing miR-154-5p by hsa_circ_0000276 in regulating Cullin-2 (CUL2) expression in human papillomavirus type 16 (HPV16)-positive cervical cancer (CC) cells. Methods Cervical tissues of individuals with normal cervix (NC), low-grade squamous intraepithelial lesions (LSIL), high-grade squamous intraepithelial lesions (HSIL), and HPV16-CC were collected. hsa_circ_0000276 level in cervical tissues and cell lines was determined using real-time fluorescence quantitative PCR (qRT-PCR). A shRNA expression vector was constructed for the circular RNA—hsa_circ_0000276. CC cells were transfected with sh-hsa_circ_0000276 or sh-NC. The cell counting kit-8, scratch healing, transwell migration assays, and flow cytometry were used to assess the proliferation, migration, invasiveness, cell cycle distribution, and apoptosis of cells, respectively. Mechanistically, the targeting and regulatory activity between hsa_circ_0000276 and miR-154-5p were confirmed using the Dual-Luciferase Reporter gene assay and rescue experiments. Results The expression of hsa_circ_0000276 was significantly higher in CC tissues and cells. Functionally, knockdown of sh-hsa_circ_0000276 decreased proliferation, migration, and invasiveness, slowed the cell cycle, and enhanced apoptosis. Mechanistically, hsa_circ_0000276 could bind miR-154-5p and prevent miR-154-5p from reducing the levels of CUL2. Notably, the application of miR-154-5p inhibitor significantly rescued hsa_circ_0000276-mediated tumorigenesis. Conclusion hsa_circ_0000276 is upregulated in HPV16-positive CC and promotes CC progression by regulating the miR-154-5p/CUL2 pathway, suggesting that it may be a target of CC treatment.