Immortalized Human Adult Hepatocytes (hepaRG)

HepaRG is a unique human bipotent progenitor cell line, originally isolated from a hepatocholangiocarcinoma associated with hepatitis C infection. Its advantage lies in its exceptional ability to undergo terminal differentiation into a stable, metabolically competent co-culture comprising both hepatocyte-like and biliary-like cells-a dual phenotype that recapitulates the cellular heterogeneity of human liver parenchyma.

Unlike HepG2, C3A, or Fa2N-4 cells, differentiated HepaRG hepatocytes express near-physiological levels of Phase I (CYP3A4, 1A2, 2B6, 2E1), Phase II (GST, UGT), and Phase III (uptake/efflux transporters) machinery, with CYP3A4 activity directly comparable to that of primary human hepatocytes (PHHs) and authentic human liver tissue. They retain functional nuclear receptor signaling (CAR, PXR, AhR), appropriate responsiveness to typical inducers/inhibitors, and intact hepatic polarity evidenced by formation of functional bile canaliculi and tight junctions-features uniformly absent or grossly deficient in conventional hepatoma lines.

HepaRG cells overcome the critical limitations of primary human hepatocytes-scarce donor tissue, prohibitive cost, inter-donor variability, and rapid phenotypic dedifferentiation-by offering unlimited supply, standardized genetic background, and sustained functional stability for ≥21 passages and several weeks in culture. This enables chronic toxicity studies, high-throughput screening, and mechanistic time-course experiments that are simply unattainable with PHH.

HepaRG is the only hepatoma-derived line permissive to hepatitis B virus (HBV) infection, supporting the complete viral life cycle and serving as the gold-standard in vitro model for HBV entry studies and antiviral screening. Its functional polarity and bile acid handling capacity position it as an indispensable tool for drug-induced cholestasis study, permitting real-time visualization of canalicular dynamics and quantification of biliary efflux. Furthermore, HepaRG cells readily form 3D spheroids with enhanced CYP/FMO activity and albumin secretion, enabling advanced co-culture paradigms and high-content/high-throughput screening in physiologically relevant formats.