CircRNA Is a Rising Star in Researches of Ocular Diseases

Abstract

A newly rediscovered subclass of noncoding RNAs, circular RNAs (circRNAs), is produced by a back-splicing mechanism with a covalently closed loop structure. They not only serve as the sponge for microRNAs (miRNAs) and proteins but also regulate gene expression and epigenetic modification, translate into peptides, and generate pseudogenes. Dysregulation of circRNA expression has opened a new chapter in the etiology of various human disorders, including cancer and cardiovascular, neurodegenerative, and ocular diseases. Recent studies recognized the vital roles that circRNAs played in the pathogenesis of various eye diseases, highlighting circRNAs as promising biomarkers for diagnosis and assessment of progression and prognosis. Interventions targeting circRNAs provide insights for developing novel treatments for these ocular diseases. This review summarizes our current perception of the properties, biogenesis, and functions of circRNAs and the development of circRNA researches related to ophthalmologic diseases, including diabetic retinopathy, age-related macular degeneration, retinopathy of prematurity, glaucoma, corneal neovascularization, cataract, pterygium, proliferative vitreoretinopathy, retinoblastoma, and ocular melanoma.

CircHIPK3: Key Player in Pathophysiology and Potential Diagnostic and Therapeutic Tool

“…Numerous studies have shown that circRNA plays an important role in the pathophysiological processes of various diseases, such as cancer and cardiovascular disease, and in the development of neurons. Furthermore, studies have shown that circRNA also affects the occurrence and development of fibrotic diseases of organs such as the heart, lungs, and kidneys, playing a key role in organ fibrosis ( 1 , 4 – 9 ). It has been shown that a member of the circRNA family, circHIPK3, is abnormally upregulated in organ fibrosis, cancer, and other diseases, suggesting that circHIPK3 is involved in these diseases.…”

CircAMOTL1 Promotes Tumorigenesis Through miR-526b/SIK2 Axis in Cervical Cancer

“…Non-coding RNAs have been manifested not to be the transcriptional noise, and but to be the important regulatory molecules ( Zhuang et al, 2015 ; Chen et al, 2016 , 2017 ; Li et al, 2016a , b ; Tran et al, 2020 ), and circRNAs are novel endogenous non-coding RNAs that have been identified as owing key regulatory roles in the cancer biology ( Ma et al, 2019 ; Di Agostino et al, 2020 ; Dong et al, 2020 ; Jin et al, 2020 ; Li and Wang, 2020 ; Liu et al, 2020 ; Ou et al, 2020 ; Zhang et al, 2020a ). circRNAs act as important roles in the development and progression of cancers and are involved in various biological processes, such as cell proliferation, apoptosis, and migration by regulating gene expression ( Liu et al, 2019 ; Di Agostino et al, 2020 ; Ji et al, 2020 ; Tang and Chen, 2020 ; Wang et al, 2020c ).…”

“…Silencing of SIK2 reversed malignant cervical carcinomas cells phenotypes promotion of overexpression circAMOTL1. Some studies illustrated that circRNAs and miRNAs could play important roles in cervical cancers ( Jayamohan et al, 2019 ; Dong et al, 2020 ; Jin et al, 2020 ; Li et al, 2020 ; Ou et al, 2020 ; Tang and Chen, 2020 ; Tran et al, 2020 ; Zhang et al, 2020a ). Previously, the function of circAMOTL1 in cervical cancers is completely unknown.…”

“…CircRNAs belong to a special class of non-coding RNA molecules, which are also the latest research hotspots in the field of RNA. Different from linear RNA(with 5′ and 3′ ends), and circRNA molecule has a closed circular structure, that is not affected by RNA exonuclide, and its expression is more stable and not easy to degrade ( Dong et al, 2020 ; Jin et al, 2020 ; Zhang et al, 2020a ). In terms of functions, recent studies reveal that circRNA molecules are rich in microRNA (miRNA) binding sites, and act as a miRNA sponge in cells, thereby removing the inhibition of miRNA on its target genes and increasing the expression level of target genes ( Di Agostino et al, 2020 ; Li and Wang, 2020 ; Liu et al, 2020 ).…”

“…Circular RNA could regulate gene expression at the transcriptional and post-transcriptional levels ( Di Agostino et al, 2020 ; Dong et al, 2020 ; Jin et al, 2020 ; Li and Wang, 2020 ; Liu et al, 2020 ; Zhang et al, 2020a ). CircAMOTL1 is found in human chromosome 11:94532555-94533477 and is upregulated in breast cancer tissues and could promote breast cancer progression ( Ma et al, 2019 ; Ou et al, 2020 ).…”