Cui, Z.-M.; Lu, J.; Xu, Y.-Y.; Feng, Y.-Y.; Guo, Y.; Gao, Y.-P.; Wang, W.; Qiu, L.-L.; Wang, X.-Y.; Hua, Z.-C.; Wang, T.-Y.; Jia, Y.-L.

Chinese hamster ovary (CHO) cells serve as the primary host for industrial therapeutic protein production, yet enhancing their productivity remains a significant challenge. Epigenetic regulation, particularly RNA N6-methyladenosine modification, offers a promising strategy. Here, we show that the m6A reader protein insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) positively regulates recombinant protein yield in CHO cells. IGF2BP2 expression was elevated in high-producing clones, and its stable overexpression promoted cell proliferation, increased the S-phase cell proportion, and boosted titers and specific productivity of recombinant proteins-adalimumab, vitronectin, and donanemab-by 2.0-, 1.6-, 2.6-fold and 1.8-, 1.4-, 2.1-fold, respectively. Mechanistically, IGF2BP2 recognized m6A sites on HMGA1 mRNA, enhancing its stability and expression. Integrated analyses of oxidative stress, mitochondrial function, and metabolomics, along with inhibitor validation, revealed that IGF2BP2 also strengthens antioxidant defense, promotes mitochondrial ATP production and utilization, and reshapes cellular redox and metabolic homeostasis. These findings highlight IGF2BP2 as a critical regulator of recombinant protein expression and mitochondrial oxidative metabolism in CHO cells, illustrating how RNA methylation cooperates with mitochondrial function and proliferation to enhance protein production.