Translational Applications of Linear and Circular Long Noncoding RNAs in Endometriosis

Abstract

Endometriosis is a chronic gynecologic disease that negatively affects the quality of life of many women. Unfortunately, endometriosis does not have a cure. The current medical treatments involve hormonal manipulation with unwanted side effects and high recurrence rates after stopping the medication. Sadly, a definitive diagnosis for endometriosis requires invasive surgical procedures, with the risk of complications, additional surgeries in the future, and a high rate of recurrence. Both improved therapies and noninvasive diagnostic tests are needed. The unique molecular features of endometriosis have been studied at the coding gene level. While the molecular components of endometriosis at the small RNA level have been studied extensively, other noncoding RNAs, such as long intergenic noncoding RNAs and the more recently discovered subset of long noncoding RNAs called circular RNAs, have been studied more limitedly. This review describes the molecular formation of long noncoding and the unique circumstances of the formation of circular long noncoding RNAs, their expression and function in endometriosis, and promising preclinical studies. Continued translational research on long noncoding RNAs, including the more stable circular long noncoding RNAs, may lead to improved therapeutic and diagnostic opportunities.

Emerging Role and Mechanism of circRNAs in Pediatric Malignant Solid Tumors

“…CircRNAs are formed by splicing of precursor mRNAs (pre-mRNAs) and are mostly endogenous. They have no 3′ tail or 5′ cap end and are covalently closed loops ( Qu et al, 2015 ; Meng et al, 2017 ) formed by lasso-driven cyclization, direct reverse splicing, or exon skipping, or they can be cyclized by intron pairing ( Wang et al, 2021e ; Xiao et al, 2021 ). In addition, circRNAs can also be formed by RNA binding proteins (RBPs)-mediated cyclization joining the downstream 5′ end donor site to the upstream 3′ end acceptor site to form a single-stranded covalent closed-loop that joins the remaining sequence after removal of the intron ( Ali et al, 2021 ; Wang et al, 2021d ).…”