CONTINUOUS EPITHELIAL-CELL LINES FROM ADPKD LIVER CYSTS EXHIBIT CHARACTERISTICS OF INTRAHEPATIC BILIARY EPITHELIUM

We have produced continuous cell lines using retroviral transduction o f SV40 large T antigen into epithelial cells removed from the lumen of liver cysts from four female patients with autosomal dominant polycys tic kidney disease (ADPKD). Liver cyst-derived epithelial (LCDE) cell lines are grown in a hormonally supplemented medium in the presence of lethally irradiated NIH/3T3 fibroblast coculture. LCDE cells maintain their epithelial appearance and are positive for the biliary-specific markers cytokeratin 7 and 19 and gamma-glutamyl transpeptidase while being negative for hepatocyte markers. SV40 large T antigen is localiz ed to the cell nucleus. LCDE cells have been grown continuously for pe riods exceeding 12 mo and 25 passages (170 population doublings). LCDE cells exhibit intracellular pH regulatory pathways that, with one exc eption, are similar to those found in normal intrahepatic biliary epit helium. These LCDE cell lines exhibit impaired alkalinization in respo nse to Cl- substitution. This finding is suggestive of decreased funct ion or abundance of a Cl-/HCO3- anion exchanger and could account for the failure of ADPKD hepatic cysts to secrete HCO3- in response to sec retin.