Hsa_circ_0003645 shows an oncogenic role by sponging microRNA-1299 in hepatocellular carcinoma cells.

Background Studies found circular RNAs (circRNAs) and microRNAs (miRNAs) are abnormally expressed in hepatocellular carcinoma. Cancer process might be modulated by circRNA-miRNA node. Here, we focused on hsa_circ_0003645 and miR-1299. Methods RT-qPCR was used to examine hsa_circ_0003645 and miR-1299 in hepatocellular carcinoma tissues and cells. Hsa_circ_0003645 and miR-1299 were regulated by transfection. The phenotypes of hepatocellular carcinoma cells were evaluated through cell viability, colony, apoptosis, migration and invasion, and proteins associated with apoptosis and motility. Targeting relationship between hsa_circ_0003645 and miR-1299 was confirmed by dual-luciferase reporter assay. Changes in signaling transduction were monitored by Western blot. Results Hsa_circ_0003645 was notably enhanced in patients with hepatocellular carcinoma tissues and (Huh7 and SK-HEP-1) cells. Silencing hsa_circ_0003645 blocked the growth of hepatocellular carcinoma cells by inhibiting colony formation, inducing apoptosis, impeding migration and invasion, promoting the expression of apoptosis-associated proteins, and decreasing the expression of motility-relevant proteins. miR-1299 was targeted by hsa_circ_0003645 and upregulated by silencing hsa_circ_0003645. miR-1299 deficiency reversed the role of hsa_circ_0003645 silence in growth of hepatocellular carcinoma cells and signaling transduction of PI3K/mTOR pathway. Conclusion Silencing hsa_circ_0003645 buffered the growth of hepatocellular carcinoma cells. miR-1299 was responsible for the role of hsa_circ_0003645 silence.