Insertion of a suicide gene into an immortalized human hepatocyte cell line

For developing a bioartificial liver (BAL) device, an attractive alternativ e to the primary human hepatocytes would be the use of highly differentiate d immortalized human hepatocytes with a safeguard. To test the feasibility, the primary human hepatocytes were immortalized by a plasmid SV3neo encodi ng simian virus 40 large T antigen (SV40Tag) gene. A highly differentiated hepatocyte line OUMS-29 was established. A suicide gene of herpes simplex v irus-thymidine kinase (HSV-TK) was retrovirally introduced into OUMS-29 cel ls as a safeguard for clinical application. One of the resulting HSV-TK-pos itive Cell lines, OUMS-29/tk, grew in chemically defined serum-free medium with the gene expression of differentiated liver functions. OUMS-29/tk cell s were 100 times more sensitive to ganciclovir compared with unmodified OUM S-29 cells in in vitro experiments. We have established a tightly regulated immortalized human hepatocyte cell line. Essentially unlimited availabilit y of OUMS-29/tk cells may be clinically useful for BAL therapy.