Mouse Embryonic Stem Cells Differentiate Into Lung Cells
Patricia Reaney

May 16, 2002 London, UK (Reuters) -- British scientists have coaxed embryonic stem cells in mice to transform into a type of lung cell in an achievement they hope will lead to the creation of artificially grown cells and tissue for humans. Stem cells are master cells that have the capability of developing into any type of human tissue, offering the potential of regenerating tissue and organs to treat a range of diseases.

"We have just shown that one of the tissues that it can give rise to and that we can direct is a specialized cell type in the lung," Dr. Anne Bishop, of Imperial College's Tissue Engineering and Regenerative Medicine Center in London, said in an interview on Thursday. "This is the first time that anyone has shown that."

Bishop and her colleagues took mouse embryonic stem cells, placed them in a specialized growth medium and encouraged them to change into cells that line a part of the lung where oxygen is absorbed and carbon dioxide is excreted. They have already begun to replicate their findings using human embryonic stem cells in the hope of eventually replacing damaged lung cells and tissues by implanting new ones generated from stem cells. "Currently there is no therapy that uses any kind of implantation of these cells. This is something we are hoping to develop," she explained.

The researchers used the mice as a model system because they are more abundant, cheaper and easier to use, but are now running parallel experiments with human stem cells. "We are repeating the mouse experiment in humans at the moment," said Bishop.

Controversy surrounds the use of embryonic stem cells because they are derived from embryos that have been aborted or left over from in-vitro fertilization programs. Bishop said the transformed cells could help reline the lungs in patients who had lung damage or in premature infants whose lungs were not fully matured.

Unlike transplanted cells from a donor, she added, the cells could be developed so the body would not reject them. "We are currently growing these cells on natural and artificial scaffolds and the aim there is to construct lung tissue which could be used in implantation in an entire range of diseases cystic fibrosis, cancer, whatever," Bishop said. So far, they have not transplanted any of the cells into the mice.

The research, reported in the Journal of Tissue Engineering, is the result of the second year of a nine-year project. "This is the first time research of this nature has been carried out, and it has provided us with a crucial building block toward being able to construct lung tissue," Prof. Julia Polak, the Director of the unit carrying out the research, said in a statement. "It could eventually mean the end of extensive transplant waiting lists for critically ill patients," she said.