MicroRNA-223 Promotes Hepatocellular Carcinoma Resistance To Sorafenib By Targeting Inhibition Of FBW7

BackgroundHepatocellular carcinoma(HCC)has a high incidence and poor prognosis.Early diagnosis and treatment are the best treatment.However,most patients with clinically diagnosed HCC are in the advanced stage,with low surgical resection rate and lack of effective treatment.Clinical trials have demonstrated that the molecularly targeted drug sorafenib,which is effective in targeting the hallmarks of tumor cellogenesis,can significantly improve the condition of patients with advanced HCC.However,only some patients benefited,and some patients developed drug resistance,even if the efficacy of combination therapy was not satisfactory.Recent studies on the molecular mechanisms of microRNAs(MiRNAs)suggest that the regulation of various signaling pathways that miRNAs may regulate[22],dysregulation of miRNAs,plays a different role in the resistance to sorafenib,which may be the cause The cause of sorafenib resistance.The aim of this study was to reveal the regulatory relationship between miR-223 and the mRNA target F-box and WD-containing repeat domain 7(FBW7),and the role of both in regulating HCC resistance to sorafenib.Objective:To investigate the mechanism of miR-223 targets FBW7 sorafenib resistance of hepatocellular carcinoma by inhibiting FBW 7.Methods:We investigated the relationship between microRNA-223(miR-223)expression and the sensitivity of HCC cells to sorafenib treatment.miR-223 expression was determined in HCC cell lines with differential sorafenib sensitivity using reverse RT-PCR.miR-223 inhibitor,miR-223 mimic,andFBW7 siRNAs were transfected into the HCC cells to regulate the expression levels of miR-223 and FBW7.Cell proliferation was evaluated using an EdU incorporation assay and CCKit-8.FBW7 protein expression levels were observed using western blotting.The TargetScan web server predicted that FBW7 is a target of miR-223,which was confirmed by western blotting.Results:1.The highest to low activity of sorafenib in HCC cells were Huh7,SNU449 and SNU387;IC50 was 8.749±.876μM,13.4±1.05μM and 15.72±1.58μM,respectively,and the expression level of miR-223 was compared with sorafenib.The IC50 showed the same trend.2.Increasing the expression of miR-223 can promote the viability of HCC cells.Inhibition of miR-223 expression can significantly increase the therapeutic effect of sorafenib on HCC cells with increased sensitivity.3.TargetScan predicts that FBW7 is a potential target for miR-223.The expression of miR-223 was increased or decreased,respectively,and it was found that there was a corresponding change in the expression of FBW7 in HCC cells as the expression of miR-223 was changed.Overexpression of miR-223 significantly inhibited FBW7,while observing the opposite effect in HCC cells that reduced miR-223 expression.4.After treatment with sorafenib,inhibition of FBW7 expression increased HCC cell viability and a higher EdU positive rate.5.There was no difference in cell viability after HCC transfected with FBW7 siRNA and FBW7 siRNA+miR-223 inhibitor.WB confirmed that FBW7 siRNA can abolish the effect of miR-223 inhibitor on increasing FBW7 expression.Conclusion:miR-223 expression is upregulated in sorafenib-resistant HCC cells,and miR-223 knockdown significantly enhances HCC cell sensitivity to sorafenib by increasing expression of the target gene,FBW7,suggesting that miR-223 might be a new therapeutic target for overcoming sorafenib resistance.