HUMAN CELL AS PLATFORM FOR TRANSIENT EXPRESSION OF RECOMBINANT CHORIONIC GONADOTROPIN HORMONE

Human chorionic gonadotropin (hCG) is a glycoprotein, with α and β chains of Mw 14.6 kDa and 24 kDa, respectively, produced by placenta during pregnancy. For therapeutic uses, it is obtained from urine of pregnant women or produced recombinant by CHO cells (rhCG). The former lacks security while the later bears odd glycosylation pattern. This work addresses production of rhCG in HEK-293, a human cell, and comparison to rhCG of CHO cells. HEK-Expi-293® cultures in stirred flasks were transiently co-transfected onetime with plasmids carrying separately α and β hCG chain genes (proportions 1:1, 2:1 and 1:5) and cultivated along 7 days. SDS-PAGE analysis of these supernatants showed several bands circa the expected rhCG Mw of 37 Da. We conclude that HEK-293 afforded heterologous expression of hCG, in the culture conditions used, and that the range of Mw for rhCG was wide in HEK-293 compared to CHO´s rhCG, probably due to different glycan moieties. The different proportions of α:β did not increase the intensity of rhCG bands seen on the gels, suggesting there was no increase in its concentrations. More tests are currently ongoing, using Sigma® hCG ELISA Test, for rhCG content determinations, and Western-Blotting, for authenticating the rhCG gel bands.