Comparative Analysis of the Efficiency of Insertion of Genetic Cassettes into the Genome of CHO Cells Based on Non-Homologous Recombination and Integration by the PiggyBac Transposase

Industrial production of recombinant protein in Chinese hamster ovary (CHO) cells is currently performed in various ways, in particular, using the method of genomic amplification under the methotrexate (MTX) treatment. However, this approach has significant disadvantages. A possible solution is the use of transposon delivery systems. The aim of this study is to analyze the efficiency of insertion into the genome of CHO cells of genetic cassettes with the promoter region of the EEF1A1 gene during non-homologous recombination and integration by the PiggyBac transpose. The objectives of the work are: 1) obtaining of constructs containing genetic cassettes with the promoter repeat gene EEF1A1 and inverted PiggyBac systems; 2) transfection of a CHO cell with the resulting main plasmid and supplementary plasmid containing the PiggyBac transpose; 3) conducting genomic amplification under the influence of MTX; 4) analyzing the efficiency of protein expression during non-homologous recombination and integration by the PiggyBac transposase: the relative amount of GFP in cells and the number of copies of the integrated gene. It is anticipated that the efficiency of obtaining GFP using the PiggyBac system will be higher than with conventional selection using MTX.