Wednesday, November 17, 2010

Canadian Researchers Change Skin into Blood

When scientists at Hamilton’s McMaster University noticed that a petri dish full of long, thin skin cells now also had a quite different occupant characteristic, round blood cells they suspected they were on to something big. The researchers’ guess, it seems, was dead on. As described in the journal Nature yesterday, the team under Dr. Mick Bhatia seized on that chance microscopic sighting and devised a process that transforms skin cells directly into blood, a mind-bending breakthrough that one expert suggests may turn cell biology “upside down.”

The discovery opens the door to creating healthy blood from a measly patch of skin. For leukemia sufferers unable to find a bone-marrow donor and other patients the novelty could one day prove life saving. “This work from Mick Bhatia’s laboratory represents a very important, if not a seminal, contribution,” said Dr. Michael Rudnicki, head of the Stem Cell Network.

“When I read the paper, I went, ‘Wow, far out.’” Scientists in Japan managed to get a type of stem cell from skin in groundbreaking work unveiled three years ago. Stem cells are famous for their ability to change into any other type of human cell, holding out the promise of fixing diseased or damaged parts of the body, from injured spinal cords to ill hearts and diabetic pancreases. Dr. Bhatia’s discovery appears to go a major step further than that research, eliminating the middle stage of creating those induced pluripotent stem (iPS) cells, and directly reprogramming skin into other types of cell.

“One of the most important things is, you’re actually making the right cells,” said Dr. Bhatia. More fundamentally, the findings propose that even cells that have differentiated into a particular type be it skin, heart or liver are not frozen in that state and can be directly reprogrammed to do other things, much like stem cells themselves, experts say. “It really underscores that the committed cell state is not so definite. We can modulate that and make a cell step sideways into any particular state we want,” said Dr. Rudnicki. “Everything gets turned upside down.”

And the process was not overly complex, said Dr. Cynthia Dunbar of the U.S. National Heart, Lung and Blood Instiute. “If it’s that simple, it’s really interesting: that a single transcription factor, a single molecular signal in the cell, is able to make that big a difference.” “Instead of … taking an observation and ignoring it, thinking it’s an anomaly, you can try to repeat it,” said Dr. Bhatia. “When you can repeat it, creating round (blood) cells, you start to take it seriously.”