Identification and integrated analysis of key differentially expressed circular RNAs in ER-positive subtype breast cancer.

Aim: To systematically profile and characterize the circular RNA (circRNA) expression pattern in estrogen receptor (ER)-positive breast cancer (BC). Materials & methods: CircRNA expression profile was performed in ER-positive BC and adjacent nontumor tissues. The differentially expressed circRNAs (DECs) was analyzed by bioinformatics. The analysis findings were validated by quantitative real-time PCR. Results: In total, 3653 DECs were detected in our ER-positive BC compared with the control. Bioinformatics analysis showed that some pathways related to cancer, especially BC, were significantly enriched. Additionally, hsa_circ_0087378 was validated to be downregulated in ER-positive BC and the hsa_circ_0087378-miR-1260b-SFRP1 axis was proposed to be a key regulatory pathway. Conclusion: This study revealed the general expression characteristics of specific DECs in ER-positive BC and hsa_circ_0087378 might be a promising candidate target.