Circular RNA in Retina: A Potential Biomarker and Therapeutic Target

Circular RNA (circRNA) is a newly discovered noncoding RNA, which forms a closed ring with more than 200 bases in length. CircRNA is formed by back splicing of precursor RNA, and its expression abundance in body fluid is up to 10 times that of homologous linear transcripts. Recently, novel activities for circRNA in various diseases have emerged, ranging from cancer therapy and neurodegenerative diseases. Here, we reviewed the literature on the biogenesis of circRNA and its relationship with retinal diseases in recent years. We first described the mechanism, existing form and main function of circRNA. Next, we also pinpoint that circRNA has great value in the diagnosis and treatment of retinal diseases represented by retinoblastoma, retinal degeneration, and diabetic retinopathy. By this review, we hope to explore more possibilities of circRNA in clinical diagnosis and treatment.

Circular RNAs and tumors

Circular RNAs (circRNAs) are a novel type of RNA that differ from linear RNAs; they have the ability to regulate gene expression and are found to be diverse in various cell types. circRNAs mostly originate from exons or introns, are generated by back splicing or lariat introns, and are evolutionally conserved, stable and tissue specific. These properties confer them different functions, such as microRNA sponge, regulating splicing and expression, and modifying the expression of parental genes. In this paper, we will review the diversities and properties of circRNAs, their roles in cancer, and their effects in cancer targeted therapy.