lncRNA FEZF1-AS1 contributes to cell proliferation, migration and invasion by sponging miR-4443 in hepatocellular carcinoma

As one of the most common and aggressive cancer types, hepatocellular carcinoma (HCC) leads to a large number of fatalities every year. However, the pathogenesis of HCC remains largely unknown. In the present study, it was identified that FEZF1-AS1 was significantly upregulated in HCC cell lines and tissues, as determined by reverse transcription-quantitative polymerase chain reaction. Additionally, it was observed that higher expression of FEZF1-AS1 in patients with HCC indicated poorer prognosis. Furthermore, it was identified that knockdown of FEZF1-AS1 markedly inhibited the proliferation, colony formation, migration and invasion of Hep3B and Huh7 cells, as determined by Cell Counting Kit-8, colony formation and Transwell assays. In terms of mechanism, it was observed that FEZF1-AS1 acted as a sponge for microRNA (miR)-4443. The results of a luciferase reporter assay revealed that overexpression of miR-4443 significantly inhibited the luciferase activity in Hep3B and Huh7 cells. Additionally, miR-4443 overexpression markedly inhibited the expression of FEZF1-AS1, and vice versa. It was additionally identified that miR-4443 was downregulated in HCC tissues. There was an inverse correlation between the expression of miR-4443 and FEZF1-AS1 in HCC tissues. Furthermore, through functional experiments, it was identified that knockdown of FEZF1-AS1 significantly inhibited the proliferation, migration and invasion of HCC cells, whereas inhibition of miR-4443 reversed these effects. Collectively, the present results demonstrated that FEZF1-AS1 acts as an oncogene by acting as a sponge for miR-4443.