Targeted Knockdown of CCND1 by shmiR Induces Cell Cycle Arrest and Boosts Recombinant Protein Production in a CHO-K1 Cell Line

MicroRNAs (miRNA) or their mimics, have played an important role as tools for engineering different pathways in recombinant Chinese hamster ovary (CHO) cells to improve protein production. Computational biology research shows that protein-coding genes account for 1% and above of the gene population while controlling thousands of genes through miRNA regulation. To date, research focusing on recombinant protein production in CHO cells mostly explored genes linked to cell growth, metabolism, apoptosis, protein folding and secretion. However, investigations into the direct targeting of vital cell cycle genes in a complex and their effect on protein production are relatively limited. The goal of this research is to identify an essential cell cycle target gene through computational and systems biology analysis followed by its direct targeting, employing a designed miRNA mimic (shmiR) to maximize recombinant protein output within CHO cells. The conservation of metabolic energy within growth-arrested cells using this approach plays a role in elevating productivity because such cells would have used this energy for biomass production instead. The findings in our study open new possibilities for enhancing transient recombinant protein manufacturing in mammalian cells with potential impacts for both research and biopharmaceutical development efforts.