Abstract: Objective To investigate the effect of miR-491-5p targeting and regulating FGFR4 on the proliferation and migration of hepatoblastoma and its possible mechanism. Methods The expressions of miR-491-5p and FGFR4 mRNA in 15 cases of pediatric hepatoblastoma tissues and adjacent normal tissues, the normal hepatocytes cells LO2 and hepatoblastoma cells HuH-6 were detected by qRT-PCR, and the expression level of FGFR4 protein was detected by Western blot. TargetScan database predicted the target of miR-491-5p, and the relationship between miR-491-5 and FGFR4 was detected by luciferase activity assay. After the mimic NC, miR-491-5p mimic, pcDNA3.1 plasmid and pcDNA3.1-FGFR4 plasmid were all transfected into HuH-6 cells, the expression of FGFR4 was detected by qRT-PCR and Western blot, the cells proliferation was detected by CCK-8, the cell migration assay was detected by Transwell assay, and the expression of GSK3β/β-catenin signaling pathway related proteins was detected by Western blot. Results The expression level of miR-491-5p in pediatric hepatoblastoma tissues and HuH-6 cells was lower than that in adjacent normal tissues and hepatocyte cells LO2(P<0.05), while the expression level of FGFR4 was higher than that in adjacent normal tissues and hepatocyte cells LO2(P<0.05). TargetScan database predicted that miR-491-5p and FGFR4 had binding sites. Compared with the mimic NC group, overexpression of miR-491-5p inhibited the expression of FGFR4, the proliferation and migration of hepatoblastoma cells HuH-6, and the ratios of p-GSK3β/GSK3β, p-β-catenin/β-catenin and p-C-myc/C-myc(all P<0.05). Compared with mimic+Pc group, overexpression of FGFR4 could reverse the inhibitory effect of miR-491-5p on the proliferation and migration of HuH-6 cells, and the ratio of p-GSK3β/GSK3β, p-β-catenin/β-catenin and p-C-myc/C-myc(all P<0.05). Conclusion miR-491-5p negatively regulates FGFR4 to inhibit the proliferation and migra-tion of hepatoblastoma cells, which may be related to the inactivation of GSK3β/β-catenin signaling pathway.

Key words: Hepatoblastoma cells, miR-491-5p, FGFR4, GSK3β/β-catenin signaling pathway, Proliferation, Migration  ,