By Ian Sample
http://www.guardian.co.uk/science/2010/nov/08/skin-cells-blood

Scientists have turned clumps of human skin into blood cells in a feat that could revolutionise cancer therapy and the treatment of blood disorders such as anaemia.
Patients who need blood for surgery or a medical condition could have a healthy supply created for transfusion by using a patch of their own skin, researchers said.

The technique could benefit patients with leukaemia, for example, by providing them with a source of blood that exactly matches their biological make-up. Similar transfusions might help other cancer patients endure chemo- and radiotherapy, which has the side effect of destroying the body's blood-making cells.

Researchers at McMaster University in Ontario took skin cells from adults and newborn babies and converted them into blood cells by adding a gene called OCT4 along with some chemicals known as blood growth factors.

Depending on the chemicals used, the skin cells became various kinds of cell that together make up healthy blood. They included early stage red blood cells, which carry oxygen around the body, white blood cells, which fight infection, and platelets that enable blood to clot.

"If the patient has anaemia, they only need red blood cells, so we can change the recipe and make those. If we wanted to treat someone with a blood coagulation disorder, we change the recipe again and make platelets," said Mickie Bhatia, scientific director at the university's Stem Cell and Cancer Research Institute.

The team, whose work is published in the journal Nature, is the first to show it is possible to convert human skin cells directly into blood. "We have shown this works using human skin. We know how it works and believe we can even improve on the process," said Bhatia.

Cynthia Dunbar of the National Heart, Lung and Blood Institute in Maryland, said producing blood from a patient's own skin cells had the potential to make bone marrow transplants and a shortage of blood donors "a thing of the past".

"I see our first patients as being leukaemia patients. If we can take skin cells from them and turn them into healthy blood, the product could outcompete the leukaemic cells," Bhatia told the Guardian.

"More importantly, I can see this blood being used for anyone undergoing cancer therapy. Chemotherapy and radiation affect the blood system, so even though the therapy is targeting a tumour, the patient usually has to withdraw because the blood system dies as an innocent bystander. We hope our technique will provide an alternative blood source that is healthy and allows them to continue therapy and eradicate the tumour."

The team is now developing ways to produce large volumes of blood by growing patients' cells in the lab before converting them into blood cells. In further tests, the scientists will freeze and thaw the blood, with a view to keeping it in cold storage.