Circular RNA, hsa_circRNA_102049, promotes colorectal cancer cell migration and invasion via binding and suppressing miRNA-455-3p

Colorectal cancer (CRC) is the second most prevalent malignant gastrointestinal tumor type worldwide, displaying poor prognosis. Accumulating studies have reported the significance of circular RNAs (circRNAs) and microRNAs (miRNAs) in CRC carcinogenesis and development. At present, the functions and mechanisms of action underlying the circular RNA, hsa_circRNA_102049, in CRC are not completely understood. The present study aimed to establish the involvement of hsa_circRNA_102049 in CRC, as well as the associated mechanisms. The expression levels of hsa_circRNA_102049 and miRNA-455-3p were measured in CRC cell lines and tissues via reverse transcription-quantitative PCR. CRC progression was evaluated by performing Cell Counting Kit-8, flow cytometry, wound healing and Transwell invasion assays. The results demonstrated that hsa_circRNA_102049 was highly expressed in both CRC tissues and cell lines, which was associated with enhanced CRC cell proliferation, migration and invasion. Furthermore, miR-455-3p expression was downregulated in CRC cells and served as a target of has_circRNA_102049, which was validated by performing the dual luciferase reporter assay. hsa_circRNA_102049 knockdown significantly increased miR-455-3p expression, which was significantly reversed by co-transfection with the miR-455-3p inhibitor. Notably, miRNA-455-3p overexpression alleviated hsa_circRNA_102049-mediated induction of CRC cell proliferation, migration and invasion. The present study clearly demonstrated that miRNA-455-3p was a target of hsa_circRNA_102049. Moreover, the results indicated that the circular RNA, hsa_circRNA_102049, may function as a tumor promoter in CRC via directly sponging miRNA-455-3p.