Circular RNA Circ100084 functions as sponge of miR‑23a‑5p to regulate IGF2 expression in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has become a major cause of cancerrelated mortality worldwide. Circular RNAs (circRNAs) are noncoding RNAs that serve important roles in multiple cancers. However, the role of circRNAs in HCC remains largely unknown. In the present study, a circRNA microarray dataset of HCC samples, GSE97332, was downloaded from the gene expression omnibus database. Following data preprocessing, differentially expressed circRNAs between HCC tissues and normal tissues were determined using GEO2R. The circRNAmiRNA interactions were predicted by the miRanda database. The miRTarbase database was used to search for target genes of the miRNAs. A circRNAmiRNAmRNA network was constructed using Cytoscape based on the obtained circRNA, miRNA and mRNA. In this network, the upregulated circRNA hsa_circRNA_100084 was found to be involved in a competing endogenous relationship of hsa_circRNA_100084hsamiR23a5p insulinlike growth factor 2 (IGF2). The differential expression of hsa_circRNA_100084, hsamiR23a5p and IGF2 in HCC tissues and liver cancer cells was validated by reverse transcriptionquantitative PCR. Additionally, the interactions between hsamiR23a5p with hsa_circRNA_100084 and IGF2 were validated by dualluciferase reporter assays. Knocking down hsa_circRNA_100084 inhibited the proliferation, migration and invasion of liver cancer cells, while the simultaneous overexpression of IGF2 reversed the effects of hsa_circRNA_100084 knockdown. The results show that hsa_circRNA_100084 could promote the expression of IGF2 by acting as a sponge of hsamiR23a5p in liver cancer cells.