Identification of Circular RNA hsa-circ-0006969 as a Novel Biomarker for Breast Cancer

Background: To investigate the characteristics of circular RNA hsa-circ-0006969 in breast cancer and identify it as a novel biomarker for breast cancer.Methods: Three breast cancer (BC) patient tissues were selected to per-form human circRNA microarray analysis. GeneSpring 13.0 (Agilent) software was applied for analyzing the data. Another 116 BC patients were recruited for verification. Hsa-circ-0006969 was found as a potential circRNA for BC diagnostic biomarker. The structure of hsa-circ-0006969 was predicted by circPrimer1.2 software. MiRanda v3.3, RNA hybrid 2.1, and Cytoscape 3.6.0 were used for predicting the networks of circRNA-miRNA. T-test, Curve regression, and ROC analysis were applied to certify the diagnostic values of hsa-circ-0006969. Using SPSS25.0 software to perform the Statistical analysis. Results: 546 higher expression and 1475 lower expression circRNAs were identified. Four circRNAs were filtrated for further verification. Hsa-circ-0006969 was significantly low expressed in BC tissues and peripheral blood. Hsa-circ-0006969 was confirmed as higher diagnostic correla-tion with BC tissues (AUC = 0.965) and peripheral blood (AUC = 0.842), with Grade 1 (AUC = 0.639), ER -posi-tive (AUC = 0.612), TNM I (AUC = 0.693), TNM II (AUC = 0.712), TNM III (AUC = 0.757), TNM early stage(I, II) (AUC = 0.709). Hsa-circ-00069 69 presented more effective diagnostic values for tumor metastasis (AUC = 0.784) compared with CA153 (AUC = 0.752).Conclusion: Hsa-circ-0006969 could be a novel biomarker for the diagnosis and treatment of BC.