Circular RNA sponge, also known as circRNA sponge, is a synthetic RNA molecule derived from in vitro transcription (IVT) and circularization by permutated intron exon (PIE) or enzymatic ligation. circRNA sponge acts as a competitive inhibitor of specific miRNA. It contains multiple binding sites (MREs) for sequestering and “sponging” miRNA, thus preventing miRNA interaction with endogenous target mRNA. Compared to linear RNAs, circRNA sponges lack 5’ cap and 3’ poly(a) tail and are more resistant to exonucleolytic degradation resulting in higher intracellular levels for miRNA target derepression. circRNA sponges overcomes the toxicity exhibited by anti-miRNA oligonucleotides (AMO) and dosage constraint by the plasmid-based miRNA sponge. circRNA sponges does not require nucleoside modifications and are inherently non-immunogenic.
Applications of circular RNA sponge:
- Gene regulation engineering
- Functional studies of miRNAs
- Biomarker discovery and diagnostics
- Therapeutic interventions
