Development of recombinant Chinese hamster ovary cell lines for therapeutic protein production

•Overall explanation of cell line development scheme.•Comparison between two expression systems (DHFR system and GS system).•Recent advances in high-throughput technology for cell line screening.•Mechanism and application of site-directed integration technology.•Use of DNA elements for constant expression of product.

The current biopharmaceutical market is driven by the steady increase in demand for recombinant therapeutics produced in mammalian cell lines. Chinese hamster ovary (CHO) cells are the predominant workhorses for large-scale stable expression of human glycoproteins. However, the low throughput and time-consuming process of cell line development, heterogeneity and instability of CHO cell lines pose serious challenges. This review highlights the conventional expression system with its limitations and the recent advances in high throughput screening methods for rapid clonal selection, targeted gene integration methods for precise prediction of transcriptional activities, and engineering of DNA elements to improve the stability of CHO cell lines.