CircMYH9 increases KPNA2 mRNA stability to promote hepatocellular carcinoma progression in an EIF4A3-dependent manner

Hepatocellular carcinoma (HCC) is the most commonly diagnosed cancer worldwide with a high incidence of recurrence and metastasis; however, the molecular mechanisms underlying HCC development remain to be fully understood. In this study, we identified circMYH9 as an important regulator of HCC. Overexpression of circMYH9 induced, while knockdown of circMYH9 inhibited, the proliferation, migration, and invasion of HCC cells. Mechanistically, circMYH9 bound to eukaryotic translation initiation factor 4A3 (EIF4A3) and increased karyopherin subunit alpha 2 (KPNA2) mRNA stability. circMYH9 knockdown in HCC cells reduced the stability of KPNA2 mRNA. Importantly, circMYH9 regulation of HCC required the activity of KPNA2. In support with this, circMYH9 level was positively correlated with the expression of KPNA2 in HCC patient samples. Taken together, our study was the first to uncover the oncogenic role of circMYH9 in HCC and further elucidated the functional mechanism of circMYH9 by interacting with EIF4A3 to increase KPNA2 mRNA stability. Our findings might provide a novel potential target for the diagnose and treatment of HCC.