Transient expression of recombinant sPDGFR alpha-Fc in CHO DG44 cells using 50-mL orbitally shaking disposable bioreactors.

Overactivity of platelet-derived growth factor (PDGF) has been linked to malignant cancers. High levels of PDGF result in the activation of its receptors (PDGFRs) and the over-proliferation of cells. Therefore, interfering with this signaling pathway in cancer cells could be significant for anti-cancer drug development. In a previous study, the sPDGFR alpha-Fc fusion protein expressed in static CHO-k(1) cells showed an anti-proliferative effect on vascular endothelial cells. However, it was difficult to obtain a large quantity of this fusion protein for further functional studies. In the present study, the sPDGFR alpha-Fc fusion protein was transiently expressed in Chinese Hamster Ovary (CHO) DG44 cells in 50-mL orbital shaking bioreactors. sPDGFR alpha-Fc was expressed as a 250-kDa dimeric protein with potential glycosylation. The final yield of sPDGFR alpha-Fc in the culture supernatant was as high as 16.68 mg/L. Our results suggest that transient expression in orbital shaking bioreactors may be feasible for preparation of recombinant proteins used for preclinical studies.