Screening of up- and downregulation of circRNAs in HBV-related hepatocellular carcinoma by microarray.

The present study describes circular RNA (circRNA) profiles in three pairs of hepatocellular carcinoma (HCC) tissues and the corresponding adjacent non-tumorous tissues (NTs) by microarray. circRNA is a type of endogenous RNA that serve a crucial role in disease development and aberrantly express in a number of types of cancer. In the present study, 3 paired HCC tissues and paired adjacent NTs were collected from HCC surgical specimens from 3 hepatitis B virus-infected patients with HCC. With abundant and varied probes accounting for 5,396 circRNAs, a large number of circRNAs are able to be quantitatively determined. Based on the microarray data, 222,567,556 upregulated circRNAs and 125,439,219 downregulated circRNAs were identified respectively. Further analysis revealed 24 upregulated and 23 downregulated significantly circRNAs (fold-change ≥2; P≤0.05) in HCC tissues compared with NTs. By means of computer analysis and database inquiring, the microRNA (miRNA) response elements associated with the abnormally expressed circRNAs were annotated. The present study showed novel evidence determining genome-wide circRNA expression patterns in HCC using microarray analysis. The results demonstrated that clusters of circRNAs were aberrantly expressed in HCC compared with NTs. These circRNAs may be involved in the occurrence and development of HCC. Therefore, the results of the present study may provide a novel approach for improving the understanding of the molecular basis of HCC. Furthermore, the identified circRNAs may be potential biomarkers for the diagnosis of HCC.