An RNA-seq based transcriptomic investigation into the productivity and growth variants with Chinese hamster ovary cells

Chinese hamster ovary (CHO) cells are widely used in producing monoclonal antibodies (mAbs), however, these cell lines can show variants associated with productivity and growth. Fundamental understanding of cellular mechanisms can benefit high mAbs production while maintaining robust cell growth. In this study, RNA sequencing (RNA-seq) based approach was used to study the transcriptomic space among three mAb-producing CHO cell lines. A phenotypic contrast of higher productivity but lower growth was found with one cell line versus the other two cell lines. The messenger RNAs (mRNAs) from those cells at two different time points in culture were sequenced to seek the gene functions possibly associated with the phenotypic differences. It was found that the mAb transcripts from each cell line were correlated with the mAb production level, indicating a strong determination of production by the expression level of gene of interest (GOI). Further exploration in the global transcriptome showed that the high producers had more expression with genes related with secretion and protein transportation. In the meantime, the slower growth of the high producers was linked to higher regulation to cell growth as well as lower gene expression on biosynthesis, central metabolism and nutrient transport.