In silico analysis and comprehensive review of circular-RNA regulatory roles in breast diseases; a step-toward non-coding RNA precision.

In the current comprehensive review, we first highlighted circRNAs, which are key ncRNAs. Next, we discussed the relationships among circRNAs and breast cancer subtypes via in silico databases analysis and extensive literature search. CircRNAs, that sponge miRNA axes or act as silencers of oncogenic mRNAs, have been extensively addressed in the context of this review. During BC pathogenesis, the circRNA/microRNA/messenger RNA (mRNA) axis plays a major role in disease growth, progression, and survival/resistance and could be targeted for improved treatment options. This review also aimed to address oncogenic and tumor suppressor mRNAs, which are regulated by various circRNAs in BC. Moreover, we mentioned the relation of different circRNAs with cancer hallmarks, patient survival together with drug resistance. Additionally, we discussed circRNAs as vaccines and biomarkers in BC. Finally, we studied exosomal circRNAs as a hot interesting area in the research. REVIEW SIGNIFICANCE: Via using in silico databases, bioinformatics analysis, and a thorough literature search to first highlight circRNA as a crucial ncRNA and its biogenesis, and then we explored the connection between circRNA and breast illnesses. In the framework of the review, circRNA sponged-miRNAs axis or as silencers to oncogenic mRNAs were extensively discussed. In the pathophysiology of BC, the circular RNA/microRNA/messenger RNA axis is crucial for the propagation of the disease and resistance that may be targeted for more effective treatment options, in order to confront tumor suppressor and oncogenic mRNAs that are presently regulated by circRNAs in BC. For better patient results, we advised further mechanistic research to elucidate additional ncRNA axis that may be targeted for the therapy of BC and for prognosis/ or early diagnosis.