Cultured Liver Cells Now Available for Research Applications

An advance in cell culture technology will enable researchers to maintain liver cells (hepatocytes) in culture for up to 40 replication cycles, which will provide important study material for research, clinical applications, and pharmaceutical development.

Hepatocytes have a critical role in the metabolism of an organism, but their study is limited by the inability to expand primary hepatocytes in vitro while maintaining proliferative capacity and metabolic function. Heretofore, attempts to expand human hepatocytes in the laboratory have generated immortalized cancer cells with little metabolic function.

Recently, investigators at the Hebrew University of Jerusalem (Israel) and their colleagues at the biotechnology company upcyte technologies GmbH (Hamburg, Germany) described a process for growing in vitro cultures of human hepatocytes.

They reported in the October 26, 2015, online edition of the journal Nature Biotechnology that weak expression of the E6 and E7 genes from human papilloma virus (HPV) released hepatocytes from cell-cycle arrest and allowed them to proliferate in response to stimulation by Oncostatin M (OSM), a member of the interleukin 6 (IL-6) super family of cytokines, which is involved in liver regeneration. This procedure has been dubbed the "upcyte" technique.

Stimulation of cultures with OSM according to the upcyte procedure caused cell proliferation, with doubling time of 33 to 49 hours. Removal of OSM then caused growth arrest and hepatic differentiation within four days, generating populations of 1013 to 1016 highly functional liver cells from a single human hepatocyte isolate.

Differentiated hepatocytes showed transcriptional and toxicity profiles and cytochrome P450 induction similar to those of primary human hepatocytes. Replication and infectivity of Hepatitis C virus (HCV) in differentiated hepatocytes were similar to those of Huh7.5.1 human hepatoma cells.

“The approach is revolutionary,” said contributing author Dr. Joris Braspenning, CSO of upcyte technologies GmbH. “Its strength lies in our ability to generate liver cells from multiple donors, enabling the study of patient-to-patient variability and idiosyncratic toxicity.”

“This is the holy grail of liver research,” said senior author Dr. Yaakov Nahmias, professor of bioengineering at the Hebrew University of Jerusalem. “Our technology will enable thousands of laboratories to study fatty liver disease, viral hepatitis, drug toxicity, and liver cancer at a fraction of the current cost. Genetic modifications preclude using the cells for transplantation, but we may have found the perfect cell source for the bio-artificial liver project.”

Related Links:
Hebrew University of Jerusalem 
upcyte technologies GmbH