Hybrid hepatocytes regenerate the liver without giving rise to cancer
A new study has revealed a previously unidentified group of cells that can regenerate liver tissue without forming tumors. Previously, researchers believed that a group of adult stem cells known as oval cells were responsible for the liver’s renowned regenerative properties, but it has since been proven that these stem cells develop into bile duct cells.
Instead, the researchers at the University of California-San Diego School of Medicine have revealed that “hybrid hepatocytes” are behind the liver’s regeneration. Their findings are published in Cell.
At present, many researchers are testing the capabilities of induced pluripotent stem cells (iPSCs) to repair damaged livers and stop liver failure from occurring. Using iPSCs can be difficult, however, as it can be hard to stop these cells from proliferating once they have completed their therapeutic task.
As iPSCs continue to proliferate, the risk of them forming cancerous tumors also increases.
The researchers then tested to see whether the newly discovered hybrid hepatocytes had similar tumor-forming properties by examining tumors in three different mouse models of liver cancer. After failing to find evidence of hybrid hepatocytes in any of the tumors, the researchers concluded that the cells did not contribute to certain forms of liver cancer.
While the majority of the research was conducted using mouse models, the researchers were also able to identify cells similar to the mouse hybrid hepatocytes in human livers. Experts hope that one day, cell-based therapies will replace the use of liver transplants.
A group of liver stem cells known as hepatic progenitor cells (HPCs) were transplanted into mice and, over the following months, the cells spurred major areas of the liver to regenerate, improving both the structure and the function of the liver.