Liver Cell Breakthrough

L O N D O N, July 19, 2000 -- British scientists said today they have managed to derive liver cells from the precursors to blood cells — a breakthrough that could removethe need for liver transplants.

In the experiment scientists were able to show that bloodcell precursors — a type of undifferentiated cell called a stemcell which normally develops into blood cells — can alsodevelop into liver cells.

Scientists could regenerate liver tissue by the relativelysimple expedient of injecting a patient’s own bone marrow, whichcontains stem cells, into their body, the British scientistssaid.

“The potential is quite enormous; you can repopulate theliver with blood cells,” Nick Wright, a professor ofhistopathology at the Imperial Cancer Research Fund, toldReuters.

Wright, who is also a professor of pathology at ImperialCollege London, said theoretically you could take bone marrowstem cells from someone who is suffering from hepatitis — adisease of the liver — modify them to become resistant, injectthem into the blood stream and they would form new liver cells.

An Easy SourceThe stem cells can easily be harvested from an individualand then encouraged to develop into liver cells by carefulmanipulation of their environment, the scientists from ImperialCollege London, University College London and the ImperialCancer Research Fund said in an article in Nature.

“Our results should contribute to the development of humantissue for use in a therapeutic context,” they said in thejournal.

Until recently it was thought that adults’ stem cells orprecursor cells — undifferentiated cells that develop intospecialized tissues — could only develop into cells associatedwith one tissue.

But Wright said this doctrine had now been turned on itshead.

“If you had said this sort of thing three years ago youwould have been laughed out of court.”

U.S. scientists have developed a method by which stem cellscollected from aborted embryos can be cultivated. But thetechnique has been criticized on ethical grounds.

Less Ethical Problems“There is a shortage of livers to transplant but there isalso a lot of concern over using embryo stem cells to repopulatethe liver. Our technique has no such ethical limitations,”Wright added.

Experiments on mice had also shown that muscle stem cellsand brain stem cells could be made to develop into blood cellsand this may also be possible in humans, Wright said.