Background
Sorafenib, an orally active potent tyrosine kinase inhibitor (TKI), represented a primary treatment in patients with advanced hepatocellular carcinoma (HCC). Unfortunately, sorafenib resistance was regarded as a huge obstacle for HCC treatment.
Methods
RNA-sequencing including circRNA Sequencing (circRNA-Seq) for circular RNAs (circRNAs), miRNA Sequencing (miRNA-Seq) for microRNAs (miRNAs), as well as mRNA Sequencing (mRNA-Seq) for mRNAs in sorafenib-resistant HCC cells vs sorafenib-sensitive HCC cells, were performed. Then, interaction correlation analysis between differentially expressed circRNAs and miRNAs and their target genes in Huh7/SOR and SMMC7721/SOR cells was exhibited. The "circRNA-miRNA-mRNA" network was constructed through the Cytoscape software application, Circular RNA Interactome and Targetscan prediction, RNA binding protein immunoprecipitation (RIP), RNA pull-down, and Dual luciferase reporter assay. Furthermore, mRNA-Seq, Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for the downstream genes involved in the "circRNA-miRNA-mRNA" network was implemented. Iron detection assay, Lipid peroxidation quantification assay, ROS measurement assay, CCK-8 assay, and tumor challenge in vivo were used to determine the mechanisms promoting sorafenib resistance in HCC, where the "circRNA-miRNA-mRNA" network is clearly involved in.