Scientists score stem-cell victory with lab-grown liver tissue

Score one for stem cell scientists in the hunt to regenerate human livers. A group from Yokohama City University in Japan has reported that lab-grown human liver "buds" were injected into mice and performed the detoxification functions.

Scientists have many questions to probe about the approach, and the use of such methods in humans could be years away. Yet the approach opens the door to further exploration and provides some hope that stem cell science could yield breakthroughs for patients with ailing livers.

When a mixture of induced pluripotent stem cells matured into liver buds, which represent the organ in an early state, the Japanese scientists were totally "gobsmacked" by the unexpected result, a lead scientist told reporters from the BBC and other media outlets through a translator. They injected the liver buds into mice with chronic liver disease, showing that the buds seemed to function and improve the survival of the animals.

"We just simply mixed three cell types and found that they unexpectedly self-organize to form a three-dimensional liver bud--this is a rudimentary liver," said Professor Takanori Takebe, as quoted by the BBC. "And finally we proved that liver bud transplantation could offer therapeutic potential against liver failure."

Livers take a beating from Western diets and diseases such as hepatitis, driving up demand for new treatments and transplants. A regenerative therapy could prolong the function of diseased livers.

However, lab-grown liver buds could find use sooner as ways to assess the toxicity of drugs before they are tested in humans. Drug hunters have already turned to stem cell science for models of human disease, as mice offer limited evidence of how treatments impact humans.

- read the BBC's coverage
- and the report from The Toronto Star