Adaptation process of engineered cell line FCHO/IL-24 stably secreted rhIL-24 in serum-free suspension culture

• Published in: Protein expression and purification 2022-11, Vol.199, p.106154-106154, Article 106154
• Main Authors: Hua, Jilei, Wei, Yuexian, Zhang, Yao, Xu, Hanli, Ge, Jianlin, Liu, Mengzhe, Wang, Yuqi, Shi, Yinan, Hou, Lingling, Jiang, Hong
• Format: Article
• Language: English
• Subjects: CHO cells; Engineered FCHO/IL-24 cell line; Serum-free culture; Suspension culture; The recombinant human IL-24 protein
• ISSN: 1046-5928; 1096-0279
• DOI: 10.1016/j.pep.2022.106154

Interleukin-24 (IL-24) displays tumor cell-specific proliferation inhibition in vitro and in vivo. Recombinant human IL-24 (rhIL-24) has significantly higher activity, yet significantly lower expression level in mammalian cells than in bacteria. To further realize therapeutic potential of IL-24, we enhanced rhIL-24 expression in mammalian cell systems by adapting engineered Flp-InTMCHO/IL-24 (FCHO/IL-24) cells (adherent cultured in Ham's F12 medium with 10% serum) to serum-free suspension culture. First, MTT assay showed that among four different media (F12, DMEM/F12, 1640 and DMEM), DMEM/F12 medium was the most suitable media for lower-serum adherent culture. Then, cells were adherently cultured in DMEM/F12 with serum concentration reduced from 10% to 0.5% in a gradient manner. Compared to cells in 10% serum, cells in 0.5% serum displayed significantly lower relative cell viability by 40%, increased G0/G1 phase arrest (8.5 ± 2.4%, p