Direct gene transfer into mouse muscle in vivo.
Level 5 - mechanism / opinion, no new human data
Animal model study with no human data
PubMed 1690918 · doi:10.1126/science.1690918
What was done
RNA and DNA expression vectors encoding chloramphenicol acetyltransferase, luciferase, and beta-galactosidase were injected directly into mouse skeletal muscle in vivo without specialized delivery vehicles. Protein expression was assessed, localized via in situ cytochemical staining for beta-galactosidase, and tracked over time for the luciferase construct, with expression magnitude compared against in vitro transfected fibroblasts.
What was found
Protein expression was detected across all RNA and DNA constructs, yielding expression levels comparable to in vitro transfection of fibroblasts under optimal conditions. In situ staining demonstrated beta-galactosidase expression localized to muscle cells. Following injection of the luciferase DNA construct, luciferase activity persisted in skeletal muscle for at least 2 months. The abstract reports no numerical values or sample sizes.
Why it matters
This paper provides the foundational proof of concept that mammalian skeletal muscle can directly take up and express naked DNA and RNA in vivo, paving the way for non-viral gene therapy and nucleic acid vaccines.
Limits
The study is restricted to a mouse model. The abstract does not disclose sample sizes, exact quantitative yields, transfection efficiency percentages, toxicity, or potential host immune reactions to the foreign vectors or expressed proteins.
Cited by
- supports In 1990, researchers published a paper demonstrating for the first time that injected mRNA into mouse muscle cells could express protein.