|Cell Fate mRNA
TriLink has developed optimized capped and polyadenylated mRNA for cell fate determination. Cell fate mRNA mimics fully processed mRNA which is a substrate for translation by the ribosome. For some applications, mRNA is preferred over DNA or viral vectors because there is no risk of integration into the genome which can lead to insertional mutagenesis.
Eliminating the risk of insertional mutagenesis is especially important in applications such as the generation of induced pluripotent stem cells (iPSCs). Once, iPSCs are made, they are typically expanded, differentiated and sometimes implanted in animals. During this process, an insertional event can lead to a cancerous phenotype. For safety reasons, the stem cell community has moved to non-integrating approaches, such as mRNA expressing factors.
Delivery to the appropriate compartment in the cell has been a major barrier in gene therapy research. mRNA expression factors target the cytoplasm, and hence only need to cross the plasma membrane. In contrast, plasmid DNA and most types of viral vectors must reach the nucleus and therefore need to cross an additional membrane barrier. In some cell lines collaborators have observed higher transfection efficiencies with TriLink cell fate mRNA compared to DNA plasmids.
Controlled, Rapid Expression Levels
With cell fate mRNA, it is easy to control gene dosage. Expression levels achieved from different promoters used in plasmid DNA or viral vectors can vary dramatically from cell type to cell type. Ectopic promoters are also frequently transcriptionally silenced over time. With integrating viral vectors such as retroviruses or lentiviruses, the number of vector integrations and the location of integration can greatly influence expression in individual cells. All of these concerns are eliminated with mRNA because they function post-transcriptionally.
Lastly, mRNA expression factors are expressed more rapidly than DNA or virus based approaches since there is no waiting for transcription, splicing, polyadenylation and nuclear export.
For some applications, such as genome editing using zinc-finger nucleases (ZFNs) or TALEN nucleases, transient transfection is desirable. This is much more easily achieved with mRNA expression factors.