RNA Binding Protein CPSF3 Mediates Cell Cycle Arrest Via PI3K/Akt/GSK-3β Signaling Pathways And Its Significance In Clinical Characteristics And Prognosis Of Hepatocellular Carcinoma Patients

BackgroundRecent studies have shown that cleavage and polyadenylation-specific factor 3(CPSF3)has proved to be a promising antitumor therapeutic target in acute lymphoblastic leukemia and Ewing’s sarcoma,but its potential role in hepatocellular carcinoma(HCC)has not been reported.MethodsThe expression pattern of CPSF3 in HCC tissues and normal tissues in TCGA database was analyzed by bioinformatics method.Kaplan-Meier method was used to analyze the correlation between CPSF3 expression and patient prognosis,tumor stage,tumor differentiation degree,liver cirrhosis grade and liver function grade.We used TIMER online tool to analyze the correlation between the expression pattern of CPSF3 and immune cell infiltration,and the correlation between the immune infiltration and the prognosis of HCC patients.Quantitative polymerase chain reaction(q PCR),western blot(WB)and immunohistochemical techniques were used to verify the expression pattern of CPSF3 in the matched HCC tissues and normal tissues.CPSF3 knockdown model of two HCC cell lines Hep G2 and SMMC-7721 was established by transfection of si RNA.The functional changes of CPSF3 knockdown group and normal group of HCC cell lines were explored by CCK8,clone formation,flow cytometry and Ed U staining.To explore the molecular mechanism of CPSF3 knockdown affecting HCC cell lines by detecting related tumor pathways through WB.ResultsThe results showed that the transcription and protein levels of CPSF3 were significantly higher in HCC tissues than in adjacent normal tissues(P <0.05).The HCC cohort with increased expression of CPSF3 is associated with advanced stage and differentiation and predicts poorer prognosis(p<0.05).CPSF3 knockdown significantly inhibited proliferation and clone formation of Hep G2 and SMMC-7721 cell lines.Flow cytometry analysis showed G1 to S cell cycle arrest in the CPSF3 knockdown group,and the results of Ed U staining were consistent with this.Compared with the control group,p-Akt and cyclin D1 were decreased,and GSK-3βwas increased in the knockdown group.Besides,the high expression of CPSF3 was positively correlated with MDSC(myeloid-derived suppressor cell)infiltration and negatively correlated with HSC(hematopoietic stem cell)infiltration through the TCA-LIHC dataset.Moreover,high infiltration of MDSC was associated with poor prognosis of patients with HCC,and high infiltration of HSC was associated with longer overall survival of patients with HCC.Finally,through correlation analysis,the high expression of CPSF3 was found to be related to TP53 mutation.ConclusionsThis study showed that CPSF3 was significantly overexpressed in HCC tissues,and was correlated with tumor stage,tumor cell differentiation,and poor prognosis of patients.In addition,CPSF3 may inhibit HCC cell proliferation by inhibiting PI3K/Akt/GSK-3β signaling pathway mediated cell cycle arrest.Finally,high CPSF3 expression was significantly positively correlated with MDSC infiltration,both of which were associated with poor prognosis in HCC patients.