Stem cell hope for baldness

Stem cells isolated from mouse hair follicles can grow new hair when transplanted into another animal, a new US study shows. Scientists at the University of Pennsylvania School of Medicine in Philadelphia also identified a unique set of genes, which were switched on in the hair stem cells but not the surrounding cells. This will help them identify the cell's human counterparts, say the team, and could pave the way for future treatments for baldness. The findings, published in the journal Nature Biotechnology, could also help research into new burn treatments and skin cancer.

It has been known for some time that hair follicles contain stem cells, 'master' cells that can give rise to new hair and its associated tissues, but they have proved difficult to isolate until recently. In both the latest study, and another study published in Science earlier this year, by a group at the Rockefeller University in New York City, the researchers used a fluorescent green protein to 'tag' the stem cells, which could then be purified using a cell-sorting machine.

When the scientists transplanted these cells into the skin of other, hairless mice, they grew new follicles, hair, skin and oil-secreting glands. The team found that many different genes are involved in producing new hair, some of which could be targets for new drug treatments for baldness, and conditions like alopecia. The research could also help new treatments for burn wounds, which are never covered with hair follicles. 'These cells have that capability so if we can isolate them and seed them onto a wound we can constitute skin that is more normal than currently possible', said team leader George Cotsarelis.

According to Anthony Oro, a skin expert at Stanford University in California, the work could also help understand skin cancer, since it is thought that the elusive skin stem cells are the targets of the ultraviolet-light damage that triggers the disease. 'We've known where these cells are for a while, but now we finally have the prospect of getting our hands on a lot of them,' he said.