Construction And Analysis Of Circular RNA Molecular Regulatory Networks In Liver Cancer

Background and Purpose:Liver cancer is the sixth most prevalent cancer and the third most frequent cause of cancer-related death.Circular RNA（circRNA）is a novel kind of non-coding RNA.Because of the lack of free ends,circular RNAs are resistant toward exonucleases,thereby escaping normal RNA turnover.Circ RNAs can indirectly affect the function and expression of downstream genes though adsorbing target miRNAs,which play essential roles in the life and the process of cancer.This study is designed to integrate the academic advantages of Bioinformatics and Molecular Biology,explore the potential influence of circRNA on the occurance and development of liver cancer,and lay a foundation for deepenly studying the circRNA mechanism during the occurance and development of liver cancer.Meanwhile,it is also expected to provide new ideas on the study of other cancers.Material and methods:We conducted Arraystar Human circRNA Array and Arraystar Human mRNA Array to analyze the circRNA and mRNA profiles in three pair of liver cancer clinical tissues.The circRNA-micro RNA interaction was predicted with Arraystar’s home-made miRNA target prediction software based on Target Scan and mi Randa.The micro RNA-mRNA interaction was predicted with Target Scan,mi Randa and mi RDB,that match the seed region of human miRNA sequences as obtained from mi RBase,and then compared with the differentially expressed mRNAs,Cytoscape was applied to build a circRNA–miRNA–mRNA interaction.We performed the mRNAs associated pathways and gene ontology items.The significant differential expressions of representative circRNAs were further confirmed using qRT-RCR using β-actin as the internal standard.qRT-PCR was performed in Bio-Rad CFX96 system and the data were analyzed using the 2^-ΔΔCT method.Results:We totally detected 127 significantly differentially expressed circRNAs and 3235 significantly differentially expressed mRNAs with the fold charge over two.We construct circRNA and mRNA expression profiles and analysis the coding genes-mediated pathway and GO.And we construct the circRNA-miRNA-mRNA interaction network.We found that the circ FUT8,circ ZFR and circ IPO11 expression levels in liver cancer tissues were significantly higher than those in corresponding nontumorous tissues.The data indicated that microarray analysis was well consistent with qRT-PCR results regarding the expression levels of the three circRNAs.