Mechanisms By Which BOP1 Promotes The Development And Poor Prognosis Of Hepatocellular Carcinoma Through Extensive Transcriptional And Post-transcriptional Regulation

Objective:Hepatocellular carcinoma(HCC)is the most common primary malignant tumor of the liver worldwide.Block of proliferation 1(BOP1)is an RNA-binding protein gene involved in ribosome assembly and r RNA processing that has been linked to the emergence of certain gastrointestinal cancers.Therefore,we speculate that BOP1 may be crucial in the development of hepatocellular carcinoma.Methods:The Cancer Genome Atlas(TCGA)was used to identify BOP1 gene expression differences and their survival significance in hepatocellular carcinoma.Real-time quantitative PCR(RT-q PCR)and protein blotting,respectively,were used to further analyze the m RNA and protein levels of BOP1 in liver cancer tissues.Investigations focused on the genes and variable splicing events that followed BOP1 silencing in Hep G2 cells as well as those that happened in the two sets of samples taken from the TCGA HCC dataset with high and low BOP1 expression that were significantly differentially expressed.Both sets of results are compared and verified.Cell viability,cell cycle,migration and invasion were investigated in hepatocellular carcinoma cell lines with BOP1 silencing or overexpression.The cell cycle associated proteins,including c-MYC and Cyclin E1,were measured using immunoblotting.Finally,the downstream pathway of BOP1 were explored using bioinformatic analysis and q PCR.Results:Compared to paired normal tissues,liver cancer tissues were shown to have higher levels of BOP1(p < 0.0001).The genes associated with differential variable splicing events found in clinical samples and cell lines were concentrated in cell migration,apoptotic,and cell cycle pathways.This shows that BOP1 is largely responsible for the splicing of such genes and that some of these splicing events are significantly related to the prognosis of liver cancer.The overexpression of BOP1 promoted cell proliferation,migration,and invasion while silencing BOP1 showed a reversed trend.Then,bioinformatic prediction showed that the cell cycle could be a downstream pathway of BOP1.Immunoblotting results suggested that BOP enhanced c-MYC and Cyclin E1.Conclusions: This research reveals that BOP1 not only controls the hepatocarcinogenesis and development splicing genes’ variable splicing directly but also has a regulatory effect on the splicing of splicing factors,subsequently influencing the genomic transcriptional landscape indirectly.Finally,the present study demonstrated that BOP1 contributed to the development of hepatocellular carcinoma by promoting proliferation,invasion,and migration,which could be a biomarker or therapeutic target in HCC.