Lentiviral Engineered cells for production of miR34a loaded exosomes

Background: RNA antisense emerging as novel candidates for therapeutic purposes. As an RNA, miR-34a involves in P53 function, and triggers cancer cells apoptosis. The clinical applications of miRNAs face some limitation which can be potentially resolved using exosome as a transporting vehicle. Aims: The aim of this study is to create a cell factory to generate miR34a-enriched exosomes. Methods: First exosome specific sequences were inserted into miR34a. The resulting miR34a gene were transduced HEK293T cells genome with a lentiviral system. In the structure of miR34a gene 6 nucleotides were substituted to increase its packaging rate into exosomes. To maintain the secondary structure, stability and expression of the miRNA gene, changes to the miR34a gene were made using PCR Extension. Results: The results confirmed the created changes in the miR34a gene do not affect its secondary structure. The energy level of the manipulated miR34a gene was not changed in comparison with the original one. Conclusion: Our results suggested that the induced mutation (replacing 6 nucleic acids at the 3' end of miR34a) increases loading of miR34a into the exosome by 3-fold.