Circular RNAs in breast cancer diagnosis, treatment and prognosis

Recently, circRNA has become a hot topic among cancer research. CircRNA dysregulation has been discovered in a variety of malignancies and circRNAs have important functions in tumorigenesis as well as cancer progression through diverse molecular mechanisms. Recent studies claimed that various circRNAs were related with breast cancer tumorigenesis, recurrence and multidrug resistance through various mechanisms. Besides, circRNAs are crucial players in treatment resistance and correlated with patients' clinicopathological characteristics of breast cancer. Here, we summary the recent researches about the characteristics and roles of circRNAs in breast cancer.

Increasing researches have claimed that circRNAs could act as promising diagnostic and prognostic prediction biomarkers. Indeed, tissue-specific expression and resistance to exonucleases make circRNAs attractive new class of non-invasive biomarkers for clinical application. Currently, the prospective value of circRNAs as biomarkers is under investigation in clinical trials with a series of human malignancies, including breast cancer. For instance, serum hsa_circ_0001785 and hsa_circ_100219 have been investigated as promising diagnostic or prognostic biomarkers in breast cancer (NCT05771337).

The roles and underlying mechanisms of circRNAs in predicting breast cancer treatment responsiveness have also been investigated. “However, there is still no circRNA drug that can be used in clinical settings due to low specificity and instability.”, says one of the study's authors, Hailin Tang, professor in State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center. “More investigations are required to promote the application of circRNAs as targetable molecules in future clinical treatment.”

In conclusion, circRNAs have important functions in the initiation and progress of breast cancer. Understanding the mechanisms by which circRNAs function would help develop novel circRNA-based therapeutic strategy for breast cancer treatment. Further explorations especially high-quality animal studies and large-scale clinical trials are needed to transform basic researches into clinical applications.