Conserved microRNA function as a basis for Chinese hamster ovary cell engineering

Area of Science:

• Biotechnology
• Molecular Biology
• Cell Engineering

Background:

• MicroRNAs (miRNAs) regulate molecular networks and are being explored to enhance recombinant protein production in Chinese Hamster Ovary (CHO) cells.
• miRNA expression profiling and screening are crucial for identifying suitable miRNA candidates for stable genetic manipulation in CHO cells.

Purpose of the Study:

• To investigate the potential of miR-34a, a tumor suppressor miRNA, for engineering CHO cells to improve recombinant protein production.
• To assess the impact of miR-34a ectopic expression and stable depletion on CHO cell growth and function.

Main Methods:

• Selected miR-34a based on conserved sequence and function across species.
• Ectopically expressed miR-34a in CHO-SEAP cells to evaluate its functional conservation and impact on cell growth.
• Stably depleted the miR-34 family using a miRNA sponge decoy vector in CHO cells.
• Assessed changes in cell growth and recombinant product yield in both fed-batch and batch cultures.

Main Results:

• Ectopic expression of miR-34a inhibited CHO cell growth by 90% and reduced viable cell population by 30%.
• Stable depletion of the miR-34 family resulted in an approximate twofold enhancement of overall product yield.
• This yield improvement was observed in both fed-batch and small-scale clonal batch cultures, despite a negative impact on cell growth.

Conclusions:

• miR-34a retains its tumor suppressor function in CHO cells, significantly impacting cell growth.
• Stable depletion of the miR-34 family is an effective strategy for enhancing recombinant protein yield in CHO cells.
• miRNAs represent powerful tools for modifying and optimizing CHO cell performance for biopharmaceutical production.