Specific Activation of the Expression of Growth Factor Genes in Expi293F Human Cells Using CRISPR/Cas9-SAM Technology Increases Their Proliferation.

Human cell lines play an important role in biotechnology and pharmacology. For them to grow, they need complex nutrient media containing signaling proteins - growth factors. We have tested a new approach that reduces the need of cultured human cell lines for exogenous growth factors. This approach is based on the generation of a modified cell with a selectively activated gene expression of one of the endogenous growth factors: IGF-1, FGF-2, or EIF3I. We modified the Expi293F cell line, a HEK293 cell line variant widely used in the production of recombinant proteins. Gene expression of the selected growth factors in these cells was activated using CRISPR/Cas9 technology with the synergistic activation mediators CRISPR/Cas9-SAM, which increased the expression of the selected genes at both mRNA and protein levels. Upon culturing under standard conditions, the modified lines exhibited increased proliferation. A synergistic effect was observed in co-culture of the three modified lines. In our opinion, these results indicate that this approach is promising for efficient modification of cell lines used in biotechnology.