Exosome-transported circHDAC1_004 Promotes Proliferation, Migration, and Angiogenesis of Hepatocellular Carcinoma by the miR-361-3p/NACC1 Axis

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) is among the most common malignant tumors globally. Circular RNAs (circRNAs), as a type of noncoding RNAs, reportedly participate in various tumor biological processes. However, the role of circHDAC1_004 in HCC remains unclear. Thus, we aimed to explore the role and the underlying mechanisms of circHDAC1_004 in the development and progression of HCC. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect circHDAC1_004 expression (circ_0005339) in HCC. Sanger sequencing and agarose gel electrophoresis were used to determine the structure of circHDAC1_004. In vitro and in vivo experiments were used to determine the biological function of circHDAC1_004 in HCC. Herein, qRT-PCR, RNA immunoprecipitation, western blotting, and a luciferase reporter assay were used to explore the relationships among circHDAC1_004, miR-361-3p, and NACC1. RESULTS: circHDAC1_004 was upregulated in HCC and significantly associated with poor overall survival. circHDAC1_004 promoted HCC cell proliferation, stemness, migration, and invasion. In addition, circHDAC1_004 upregulated human umbilical vein endothelial cells (HUVECs) and promoted angiogenesis through exosomes. circHDAC1_004 promoted NACC1 expression and stimulated the epithelial-mesenchymal transition pathway by sponging miR-361-3p. CONCLUSIONS: We found that circHDAC1_004 overexpression enhanced the proliferation, stemness, and metastasis of HCC via the miR-361-3p/NACC1 axis and promoted HCC angiogenesis through exosomes. Our findings may help develop a possible therapeutic strategy for HCC.