Development of a phosphoproteomic workflow for the analysis of Chinese hamster ovary cell nuclei

Abstract

Monoclonal antibodies are essential for the treatment of a wide variety of human diseases such as colon cancer and arthritis. Because of the complexity of monoclonal antibodies and the need for proper post-translational modifications (PTMs), mammalian host cells are used to create recombinant proteins that are fully functional in human targets. For more than twenty years, the leading host cells for protein therapeutics have been Chinese hamster ovary (CHO) cells because they are amenable to large scale culture conditions and are easily transfected with target DNA. Although CHO cells are widely used, the current selection process for high producing lines requires the testing of growth conditions for hundreds of cell lines in order to determine their productivity rates, which can be costly and time consuming. An alternative option for cell line selection that has not been fully explored is the screening of cell lines for protein markers such as transcriptional factors that are up- or down-regulated. This could potentially lead to more rapid selection criteria and increased production of recombinant proteins.