Overexpression of circular RNA circ{sub 0}01569 indicates poor prognosis in hepatocellular carcinoma and promotes cell growth and metastasis by sponging miR-411-5p and miR-432-5p

Emerging evidence indicated that abnormally expressed circular RNAs (circRNAs) are critically involved in tumorigenesis and development of several cancers. However, the study relevant to the relationship between circRNAs and hepatocellular carcinoma (HCC) is rare. In this study, the expression of circ{sub 0}01569 in HCC tissue specimens and cells were determined by qRT-PCR. The clinical relevance of circ{sub 0}01569 was also analyzed. In addition, loss-of-function and gain-of-function assays were conducted to explore the biological functions of circ{sub 0}01569. Furthermore, tumor formation and lung metastasis studies were induced to confirm the in vitro data. Mechanistically, bioinformatics analysis and luciferase reporter assays were conducted to illustrate the underlying mechanism of circ{sub 0}01569. The results indicated that circ{sub 0}01569 was overexpressed in HCC tissue samples and cells. This overexpression is correlated with larger tumor size, advanced TNM stages and unfavorable prognosis in the patients with HCC. Additionally, circ{sub 0}01569 significantly facilitated HCC cell growth, migration and invasion. The animal studies further confirmed the in vitro results. More importantly, circ{sub 0}01569 could directly sponge miR-411-5p and miR-432-5p. The oncogenic functions of circ{sub 0}01569 is partially dependent on its regulation on miR-411-5p and miR-432-5p. In summary, circ{sub 0}01569/miR-411-5p/miR-432-5p regulatory signaling might be a rational HCC-related therapeutic target.