Circular RNAs (circRNAs) Services
Contrary to linear RNA, circular RNAs, as a form of a covalently closed continuous loop, are a kind of single-stranded RNA whose 3' and 5' ends have been fused together to form circular RNA. With our well-established platforms and techniques, excellent scientists at our Creative Biolabs have majored in the field of circRNAs for several years and are capable of providing our worldwide clients with comprehensive, one-stop services to meet the different demands of their circRNAs-associated projects.
History of circRNAs
As a single-stranded RNA loop, viroids are the first circRNA molecules discovered more than 40 years before. Then, circRNAs can be checked in the cytoplasm of eukaryotic cells using electron microscopy. At that time, circRNAs are considered as the 'junk' during abnormal splicing events. Numerous circRNAs with tissue-specific expression patterns have been discovered in recent years thanks to high-throughput RNA sequencing and well-crafted circRNA-specific bioinformatics techniques. Since then, it has become widely acknowledged that circRNAs have significant biological roles, and novel approaches for identification and functional characterization are emerging. Endogenous circRNAs are widely expressed in all human tissues and the majority of studies identify that circRNAs are cell type-specific in solid tumors. Furthermore, the high stability of circRNAs allows them to be detected non-invasively in bodily fluids, which is helpful for disease diagnosis.
Biogenesis of circRNAs
In vivo, the naturally occurring production of circRNAs is usually caused by backsplicing. RNA-binding protein dimerization (such as protein quaking) or base pairing of inverted repeat elements (such as Alu elements) can bring the downstream splice donor and upstream acceptor together to loop the intron sequences, which is regarded as the core premise of backsplicing. Exon skipping-mediated lariat formation can also result in circRNA formation. In vitro transcription can produce the precursor linear RNA, which can be further circularized by T4 ligase or specific sequences such as T4 thymidylate synthase intron and homology sequences of permuted intron-exon splicing strategy resulting in the production of the circRNAs as you wish. If an internal ribosome entry site (IRES) cassette is involved, the synthetic circRNAs can translate the target protein once delivered to cells, which facilitates the use of circRNAs in disease treatment.
Function of circRNAs
CircRNAs play a critical role in several biological processes. Functions of circRNAs:
- Act as miRNA sponges;
- Act as protein sponges;
- Enhance the protein function;
- Act as a scaffold of two proteins;
- Recruit specific proteins to certain subcellular compartments;
- Act as a template for translation.
Fig.1 General roles of circRNAs in hepatocellular carcinoma (HCC).1
CircRNAs are famous for their stability, they have at least 2.5 times longer half-time (18.8 – 23.7 h) than linear RNA (4 – 7.4 h) because of the resistance to RNase R by their circular structure. When combined with the technique of charge-altering releasable transporters, a single dose treatment of circRNA-hEPO can increase the number of reticulocytes after a week, whereas the equimolar dose of mRNA causes no obvious effect than untreated animals. Synthetic circRNAs can be regarded as a protein-expressing vector, which sheds new light on the treatment of diseases and can replace traditional mRNA as a novel form of the vaccine especially. Combined with our lipid nanoparticle tools, the high-efficiency delivery of circRNAs in model organisms such as mice can be achieved and better performance will be observed due to the extraordinary property of circRNAs.
As a well-known biotechnological company, Creative Biolabs has majored in vaccine and disease treatment for decades. Since circRNAs have a bright future, we have established a professional workforce of trained researchers and well-defined strategies in this field. We can produce the services such as Custom Circular RNAs Synthesis Service, Circular RNAs Analysis Services, and Custom LNP Formulation Services for circular RNAs. For all your questions about circRNAs, please feel free to contact us for more details about your project.
Reference
- Shen, Hao, et al. "Circular RNAs: characteristics, biogenesis, mechanisms and functions in liver cancer." Journal of Hematology & Oncology 14.1 (2021): 1-16.
