Mechanisms of Circular RNAs in Breast Cancer Progress: A Special Attention to hsa_circ_000839 and hsa_circ_0005986 as Novel Biomarkers

Breast cancer (BC) is one of the most frequently diagnosed cancers and the leading cause of death among females around the world. Circular RNAs (circRNAs) are a newly identified class of non-coding RNAs with a covalently closed circular structure. Aberration in circRNAs expression has been implicated in different cancer types, including BC. These structurally stable molecules have been illustrated as indispensable regulators of BC progression and carcinogenesis. Aberrantly downregulation of hsa_circ_000839 and hsa_circ_0005986 proposes a tumor-suppressive ability of these circRNAs in BC, suggesting that further investigation is required to interpret the mechanisms underlying the causal role of hsa_circ_000839 and hsa_circ_0005986 in BC progression. This review focused on the association of hsa_circ_000839 and hsa_circ_0005986 with BC.