The establishment and characterization of immortal hepatocyte cell lines from a mouse liver injury model.

Hepatocytes are an important research tool used for numerous applications. However, a short life span and a limited capacity to replicate in vitro limit the usefulness of primary hepatocyte cultures. We have hypothesized that in vivo priming of hepatocyte could make them more susceptible to growth factors in the medium for continuous proliferation in vitro. Here, a novel approach used to establish hepatocyte cell lines that included hepatocyte priming in vivo prior to culture with a 3,5-diethoxycarbonyl-1,4-dihydrocollidine diet was attempted. The cell line grew in a monolayer while maintaining a granular cytoplasm and a round nucleus. Electron microscopy displayed hepatocyte-like features including mitochondria, glycogen granules, and the presence of bile canaliculi. This cell line expressed many mature hepatocyte-specific genes including albumin, alpha1-antitrypsin, glucose 6-phosphatase, and tyrosine aminotransferase. Functional characteristic of hepatocytes like the ability to store glycogen, lipid, and synthesis of urea is well demonstrated by this cell line. These cells demonstrated anchorage dependent growth properties in soft agar and did not form tumors after transplantation into nude mice. This cell line can be sustained in culture for more than 100 passages (>1.5 years) without undergoing noticeable morphological changes or transformation. This novel method resulted in the establishment of an immortal, non-transformed hepatocyte cell line with functional characteristics that may aid research of cell metabolism, toxicology, and hepatocyte transplantation.