The role of circRNAs in N ⁶ -methyladenosine(m ⁶ A), cell death and clinical applications in human breast cancer

Breast cancer (BC) is widely recognized as the most frequently diagnosed neoplasm among women worldwide. Despite significant advances, improved diagnosis and treatment of breast cancer have failed to translate into earlier detection or markedly better outcomes for patients, due to challenges including late-stage presentation, metastasis, recurrence, metabolic reprogramming, and drug resistance. Identifying reliable predictive indicators for early intervention and diagnostic markers remains a priority in breast cancer research, as this is crucial for improving patient prognosis. Circular RNAs (circRNAs), a class of non-coding RNAs (ncRNAs) abundant in various tissues and human cells, are established biomarkers for diagnosing and monitoring diseases such as those affecting the nervous, cardiovascular, and immune systems. CircRNAs contribute to tumorigenesis through the regulation of proliferation, metastasis, angiogenesis, and the tumor microenvironment. A growing body of evidence has established circRNAs as key regulators in breast cancer, elucidating their specific roles in driving tumor development and progression. Nevertheless, a more comprehensive understanding of the functional roles and molecular mechanisms of circRNAs in BC is essential and requires further research. This narrative review synthesizes the current knowledge on circRNAs encompassing their biogenesis, characteristics, methylation, tumor cell death, and selectively analyzes the translational potential of circRNAs in BC patients.