In a breakthrough that could revolutionize the way leukemia is treated, Canadian researchers have found a way to create blood from a patch of a person's own skin.
That means cancer patients may not have to wait for a life-saving donor match to receive a bone-marrow transplant and then face the risk of the body rejecting the blood stem cells as foreign. The treatment for blood conditions, like leukemia and anemia, could come from transfusions derived from a patient's own skin.
"This is something that we feel very strongly that we need to pursue," said lead researcher Mick Bhatia, scientific director of McMaster University's Stem Cell and Cancer Research Institute. He noted that many patients die waiting for a suitable bone-marrow donor.
His findings, published Sunday in the journal Nature, have yet to be expanded and to undergo safety tests before doctors can treat patients in clinical trials, which Dr. Bhatia hopes to begin as early as 2012.
But already, those in the medical and research community are buzzing that the discovery, made in a petri dish in a university laboratory, holds much promise for cancer patients.
"All of us are interested on the impact of science on people ... We can see the potential impact of this on patients, so that makes it particularly exciting," said Christine Williams, director of research for the Canadian Cancer Society Research Institute. The Canadian Cancer Society helped fund Dr. Bhatia's study.
Turning skin to blood, Dr. Bhatia found, was more direct than he first believed. It didn't require reprogramming the skin cell into an induced pluripotent stem cell – an embryonic-like stem cell that can differentiate into any type of cell in the body.
Instead, using the right recipe with different proteins, all at the right time, Dr. Bhatia and his team discovered the "sweet spot" where the cells would convert from skin to blood in a matter of a month. The team found they could convert skin into multiple blood cell types.
And the cancer patient would be better off as a result. The genetic mutation in the blood that makes the patient have leukemia is not found in the skin. So when skin cells are converted into blood, the resulting blood cells would be healthy, Dr. Bhatia said.
He cautioned that these are initial observations.
"There is an incredible amount of work to be done," he said. "Right now, in terms of alternative sources of blood for these specific types of patients – patients with cancer, leukemia, genetic disorders, anemia – it's the best alternative that we've seen."
Leukemia is the cancer of the blood or bone marrow. In healthy individuals, specialized cells in the bone marrow are responsible for producing blood, including the so-called white cells that make up the immune system.
As part of the treatment for leukemia, doctors use chemotherapy or radiation to destroy stem cells, which are normally responsible for producing blood and the various components of the immune system. They then transplant stem cells from a suitable donor that will produce healthy cells. But that is all dependent on finding the right donor because otherwise the transplanted cells won't work or will be rejected.
The other option for a bone-marrow transplant is the autologous (or self) transplantation. This can be problematic, however, if the patient has cancers of the hematopoietic (blood cell) origin, because the stem cells put back into the body have a good chance of carrying the same mutation as the leukemia or lymphoma.
So if patients can produce their own blood cells, as Dr. Bhatia has discovered, they don't have to go through these risky procedures.
Dr. Williams said the McMaster team's study "gives us all the advantages of a self-transplant – no problems finding a match, no rejection – and bypasses the risk of transplanting stem cells that carry the same mutation that caused the original tumour."
For Dr. Bhatia, having a robust alternative source for treating patients that is a product of their own body could be helpful. "Will it work? Well, that's what we're going to try to find out," he said.
Caroline Alphonso