Abstract
Circular RNAs (circRNAs), continuous loops of single-stranded RNA, regulate gene expression during the development of various cancers. However, the function of circRNAs in hepatocellular carcinoma (HCC) is rarely discussed. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the mRNA levels of circ_0011385, miR-361-3p, and STC2 in 96 pairs of HCC tissues (tumor tissues and adjacent normal tissues), HCC cell lines, and L02 (human normal liver cell line) cells. The relationships between circ_0011385 expression and clinical features of HCC were evaluated. Functional experiments in vitro or in vivo were used to evaluate the biological function of circ_0011385. Bioinformatics analysis was performed to predict miRNAs and mRNAs sponged by circ_0011385. RNA immunoprecipitation (RIP) and dual-luciferase reporter gene assays were used to elucidate the interactions among circ_0011385, miR-361-3p, and STC2 (stanniocalcin 2). ChIP and dual-luciferase reporter gene assays were used to identify the upstream regulator of circ_0011385. High expression of circ_0011385 was observed in HCC tissues and cell lines and was significantly associated with tumor size, TNM stage, and prognosis. In addition, inhibition of circ_0011385 expression prevented the proliferation of HCC cells in vitro and in vivo. Circ_0011385 sponged miR-361-3p, thereby regulating the mRNA expression of STC2. In addition, the transcription of circ_0011385 was regulated by SP3. Circ_0011385 knockdown suppressed cell proliferation and tumor activity in HCC. Circ_0011385 may therefore serve as a new biomarker in the diagnosis and treatment of HCC.