The Rna-binding Protein GRSF1 Promote shepatocarcinogenesis via competitively Binding Toyy1 mRNA with mIR-30e-5p

Abstract

Background:Numerous studies have highlighted that dysregulation of RNA binding protein (RBP) expression is causally linked with human cancer tumorigenesis. The detailed biological effect and underlying mechanisms of RBP GRSF1 in hepatocellular carcinoma (HCC) remain unclear.Methods:GRSF1 expression in HCC tissues and cells was measured by western blotting and qRT-PCR assays. HCC cells with stable knockdown of GRSF1 were established using two sh-RNA encoding lentiviruses. Then the functions of GRSF1 in HCC were explored using MTT, colony formation, flow cytometry, Transwell assays and xenograft model. Transcriptometric sequencing in GRSF1-deficient MHCC-97H cells were carried out to identify the downstream effector of GSRF1. The regulatory mechanisms among GRSF1, YY1 and miR-30e-5p were investigated by RNA immunoprecipitation, luciferase assay, RNA pull down and ChIP assay.Results:GRSF1was frequently increased in HCC tissue and cells with a worse clinical outcomes in HCC. GRSF1 worked as a novel oncogenic RBP in vitro and in vivo via post-regulating the stability of YY1 mRNA. And the GUUU motifs on YY1 3`UTR 2663-2847 was the specific binding motifs for GRSF1. More interesting, YY1 feedback promoted GRSF1 expression by binding to GRSF1 promoters. In addition, YY1 was a critical target of miR-30e-5p, which was confirmed by our data that inhibited HCC hepatocarcinogenesis. Further investigation showed GRSF1 and miR-30e-5p competitively regulated YY1 via binding to its YY1 3`UTR 2663-2847 region. At last, we identified that 3-amino-6-(4-methylsulfonylphenyl)-N-phenylpyrazine-2-carboxamide (VE821) blocked HCC progression by inhibiting the GRSF1/YY1 pathway.Conclusions:GRSF1 promoted hepatocarcinogenesis via competitively binding to YY1 3`UTR 2663-2847 with miR-30e-5p.The interaction network among GRSF1, YY1 and miR-30e-5p provided a new insight for the HCC pathogenesis, and VE821 may serve as a novel agent with potential for HCC treatment via inhibiting GRSF1/YY1 axis.