Molecular mechanisms of circular RNA in breast cancer: a narrative review.

Background and Objective: Breast cancer is presently the most prevalent cancer and the leading cause of cancer-related deaths in women worldwide. Circular RNA (circRNA) is a class of closed circRNAs lacking a 5'-end cap structure and a 3'-end polyA tail, which is highly stable and widely involved in a variety of pathophysiological processes such as cell proliferation, differentiation, and apoptosis. In recent years, accumulating studies have shown that circRNAs play an important role in the development and prognosis of breast cancer, but there are fewer literature reviews on their intrinsic molecular mechanisms which is the aim of this study. Methods: This review synthesizes the findings of literature retrieved from searches of PubMed and Google Scholar databases, hand searches, and authoritative texts. Citations mainly originate from the past 3 years. The articles need to describe the role of circRNA in breast cancer; no language restrictions were imposed. Key Content and Findings: This review summarizes the latest relevant literature and systematically reviews the four main mechanisms of circRNA in breast cancer from the perspective of circRNA function. At the same time, we describe the formation mechanism, characterization, and biological functions of circRNAs. Conclusions: We reviewed the status of actual knowledge about circRNA biogenesis and functions and summarized novel findings regarding the molecular mechanism of circRNA in breast cancer. Meanwhile, this review explores the possibility of circRNAs for becoming new biodiagnostic indicators and therapeutic targets in breast cancer.

Dual effects of circRNA in thyroid and breast cancer

CircRNA, the latest research hotspot in the field of RNA, is a special non-coding RNA molecule, which is unable to encode proteins and bind polyribosomes. As a regulatory molecule, circRNA participates in cancer cell generation and progression mainly through the mechanism of competitive endogenous RNA. In numerous regulated cancer organs, the thyroid and breast are both endocrine organs, and both are regulated by the hypothalamic pituitary gland axis. Thyroid cancer (TC) and breast cancer (BC) are both sexually prevalent in women and both are affected by hormones, thus they are intrinsically linked. In addition, recent epidemiological surveys have found that, early metastasis and recurrence of breast cancer remain the main cause of survival in breast cancer patients. Although at home and abroad, studies have shown that new targeted anti-tumor drugs with numerous tumor markers are gradually being used in the clinic, evidence for potential molecular mechanisms affecting its prognosis lacks clinical studies. Therefore, we search the relevant literature, and based on the latest domestic and international consensus, review the molecular mechanisms and regulation relevance of circRNA, compare the difference of the same circRNA in two tumors, to more deeply understand and lay the foundation for future clinical diagnostic, therapeutic and prognostic studies in large samples (AU)

Dual effects of circRNA in thyroid and breast cancer.

CircRNA, the latest research hotspot in the field of RNA, is a special non-coding RNA molecule, which is unable to encode proteins and bind polyribosomes. As a regulatory molecule, circRNA participates in cancer cell generation and progression mainly through the mechanism of competitive endogenous RNA. In numerous regulated cancer organs, the thyroid and breast are both endocrine organs, and both are regulated by the hypothalamic pituitary gland axis. Thyroid cancer (TC) and breast cancer (BC) are both sexually prevalent in women and both are affected by hormones, thus they are intrinsically linked. In addition, recent epidemiological surveys have found that, early metastasis and recurrence of breast cancer remain the main cause of survival in breast cancer patients. Although at home and abroad, studies have shown that new targeted anti-tumor drugs with numerous tumor markers are gradually being used in the clinic, evidence for potential molecular mechanisms affecting its prognosis lacks clinical studies. Therefore, we search the relevant literature, and based on the latest domestic and international consensus, review the molecular mechanisms and regulation relevance of circRNA, compare the difference of the same circRNA in two tumors, to more deeply understand and lay the foundation for future clinical diagnostic, therapeutic and prognostic studies in large samples.