MAT2A Knockdown Enhances Recombinant Protein Expression in Transgenic CHO Cells Through Regulation of Cell Cycle

ABSTRACT Chinese hamster ovary (CHO) cells represent the most widely utilized host system for industrial production of high‐quality recombinant protein therapeutics. Novel CHO cell line development is achieved through genetic and cellular engineering approaches, effectively addressing limitations such as clonal variation and productivity loss during culture. Previous studies have established that MAT2A inhibition in tumor cells promotes expression of the cyclin‐dependent kinase inhibitor p21, inducing antitumor activity. Notably, p21 induction has been shown to enhance recombinant protein expression in CHO cells by triggering cell cycle arrest. In this study, we identified MAT2A as a potential regulatory target, showing significant differential expression in transfected CHO cells with elevated versus diminished recombinant protein production. To investigate this phenomenon, we generated CHO cells with MAT2A knockdown (shMAT2A) and evaluated their recombinant protein output. Results demonstrated that MAT2A silencing enhanced recombiant protein/antibody production by 1.73‐/1.70‐fold through suppression of CyclinD1, thereby activating p21 and inducing G1 phase arrest. Furthermore, pharmacological inhibition of MAT2A using small molecules increased cell volume, boosted metabolic activity, and improved specific antibody productivity of recombiant protein/antibody production by 1.88‐/2.16‐fold in transfected CHO cells. These findings advance our understanding of MAT2A‐mediated regulatory mechanisms and provide a strategic framework for developing high‐efficiency CHO cell expression systems.