Self-splicing RNA circularization facilitated by intact group I and II introns

Area of Science:

• RNA therapeutics
• Molecular biology
• Biochemistry

Background:

• Circular RNA (circRNA) offers advantages in RNA therapeutics due to stability and protein-coding potential.
• Existing circularization methods face limitations in efficiency, speed, and scalability for large RNA constructs.

Purpose of the Study:

• To develop novel in vitro RNA circularization techniques.
• To enhance the efficiency, speed, and applicability of circRNA production for therapeutic purposes.

Main Methods:

• Introduced two techniques: Permuted Intron-Exon through Trans-splicing (PIET) and Complete self-splicing Intron for RNA Circularization (CIRC).
• CIRC utilizes natural group I and group II introns without engineering.
• Demonstrated CIRC's efficiency with large RNA constructs, including full-length dystrophin.

Main Results:

• CIRC shows enhanced efficiency and speed under mild conditions compared to PIE.
• Successfully circularized large RNA constructs, overcoming previous size limitations.
• CIRC enables scarless circRNA production with potentially reduced immunogenicity and facilitates purification.

Conclusions:

• CIRC is a powerful and versatile tool for generating high-quality circRNAs.
• This method significantly advances the potential of circRNA platforms for research and therapeutic applications, particularly for genetic disorders like Duchenne muscular dystrophy.