Sickle cell – latest advances

 A sickle cell compared with with a normal red blood cell

Further to my blog on retrieving stem cells from skin cells , scientists in Alabama and Massachusetts have reported a key next step when they used the stem cell technique to give mice with sickle cell anemia a healthy new blood supply.

Lead researcher Tim Townes, molecular genetics chief at the University of Alabama, Birmingham, created a strain of mice bearing the human genes for sickle cell, a devastating inherited disease of deformed red blood cells that can’t carry enough oxygen.

Townes paired with prominent stem cell scientist Rudolf Jaenisch of the Whitehead Institute in Cambridge, Mass., to reprogram skin from those mice into embryonic-like stem cells. They coaxed the newly engineered cells to grow into blood-producing cells. Then they replaced the sickle cell-causing gene with a healthy version and infused the new cells.

The mice started producing healthy blood, and their sickle cell symptoms vanished.

“What this paper shows for the first time is you can combine all these steps,” said Konrad Hochedlinger, a researcher at the Harvard Stem Cell Institute and Massachusetts General Hospital. “It’s an important proof of principle for the usefulness of this technology to treat disease.”

Townes next is testing whether human skin cells from sickle cell patients can be similarly reprogrammed.

The study, published in the journal Science, doesn’t bring this potential therapy closer to people just yet. Big hurdles remain, including a risk of cancer from the reprogramming method.  But it may take several years of additional research to create a safe enough reprogramming method to test such an approach in people.

Elaine Warburton