Development of Apoptosis-Resistant Dihydrofolate Reductase-Deficient Chinese Hamster Ovary Cell Line

Abstract

Apoptosis-resistant dihydrofolate reductase-deficient CHO cell line (dhfrm CHO-bcl2) was developed by introduction of the bcl-2 gene into the dhfrm CHO cell line (DUKX-B11, ATCC CRL-9096) and subsequent selection of clones stably overexpressing Bcl-2 in the absence of selection pressure. When the dhfrm CHO-bcl2 cell line was used as a host cell line for development of a recombinant CHO (rCHO) cell line expressing a humanized antibody, it displayed stable expression of the bcl-2 gene during rCHO cell line development and no detrimental effect of Bcl-2 overexpression on specific antibody productivity. Taken together, the results obtained demonstrate that the use of an apoptosis-resistant dhfrm CHO cell line as the host cell line saves the effort of establishing an apoptosis-resistant rCHO cell line and expedites the development process of apoptosis-resistant rCHO cells producing therapeutic proteins. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 872–876, 2003