Elevated circRNAs circ_0000745, circ_0001531 and circ_0001640 in human whole blood: Potential novel diagnostic biomarkers for breast cancer.

BACKGROUND AND OBJECTIVES:Increasing studies have shown that circular RNAs (circRNAs) have great diagnostic potential in cancer. Here, we examined whether the blood circRNAs could be promising candidates as diagnostic biomarkers in breast cancer. METHODS:Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to detect levels of five circRNAs (circ_0000501, circ_0000745, circ_0001531, circ_0001640 and circ_0001978) in 129 patients with breast cancer, 19 patients with benign breast tumor and 13 healthy controls. The diagnostic accuracy of circRNAs was assessed using the receiver operating characteristic (ROC) curve. A circRNA-miRNA-mRNA network was constructed based on bioinformatic analysis. RESULTS:QRT-PCR validated that circ_0000745, circ_0001531 and circ_0001640 were upregulated in breast cancer, compared with benign tumor and healthy control. ROC curve analysis revealed that circ_0000745, circ_0001531 and circ_0001640 had good diagnostic potential. Notably, a signature comprising the three circRNAs showed better diagnostic potential, with the area under curve (AUC) of 0.9130 (P < 0.0001). And a circRNA-miRNA-mRNA network revealed that the circRNAs could participate in complex regulated network and thus involve in cancer development and progression. CONCLUSIONS:Taken together, our findings support the potential of circ_0000745, circ_0001531, circ_0001640 and the three-circRNA signature as biomarkers for breast cancer diagnosis.