CircRNA expression profiles of breast cancer and construction of a circRNA-miRNA-mRNA network.

CircRNAs are a group of endogenous small noncoding RNAs that are involved in multiple diseases including cancers. At present, the functions of circRNAs in breast cancer need to be further explored. In this study, 3 pairs of breast cancer and paracancer tissues with axillary lymph node metastasis were collected for circRNA high-throughput sequencing. We have identified 17,966 distinct circRNA candidates. Significant differential expressions were found in 136 circRNAs in breast cancer tissues relative to the matched paracancer tissues. We aslo identified differentially expressed 156 miRNAs and 1105 mRNAs in breast cancer tissues and normal breast tissues from public databases. Then we constructed a regulatory ceRNA network. 12 mRNAs were associated with prognosis of breast cancer. We also constructed a circRNAs-mediated subnetwork which might be related to prognosis of breast cancer. This article provides a better understanding of circRNAs-mediated ceRNA regulatory network by which circRNAs compete for endogenous RNAs in breast cancer.