October 14, 2011
Scientists Discover New Possible Therapy For Sickle Cell Anemia
Scientists, funded by the National Institutes of Health, have discovered a way to turn on the mechanism that creates fetal hemoglobin. Fetal hemoglobin is in the human body during the fetal stage of life up to around 3 to 6 months after birth. Scientists have known for years that increased levels of fetal hemoglobin reduce the onset of the misshapen blood cells that cause the symptoms of sickle cell anemia; symptoms include pain, strokes, organ dysfunction and premature death.
The scientists studied the blood cells of mice who had their hemoglobin genes removed and replaced with the human version that contained the genetic code to create sickle cells, according to Sciencemag.org. But when they turned off the BCL11A protein, the protein that helps shut down fetal hemoglobin production, in the red blood cells the symptoms for sickle cell anemia reversed, with no apparent side effects.
Dr. Stuart Orkin of the Howard Hughes Medical Institute and Harvard Medical School, and chief investigator for the study said, “I think we´ve demonstrated that a single protein in the cells is a target that, if interfered with, would provide enough fetal hemoglobin to make patients better. It´s been hypothesized for three decades that fetal hemoglobin could be turned on once we understood the mechanism of hemoglobin switching, and this is the first evidence of a target to do that.”
Now that scientists have a target protein to manipulate, they have the job of creating a mechanism to deliver the change into the body. Sciencemag.org notes that there are two ways to deliver the treatment into the body. One way would be to shut down the BCL11A protein with strands of RNA, in blood-forming stem cells to be given to the person with the disease. The other option would be to create a drug that would inhibit the protein directly using a small molecule.
Hematologist Alex Felice, of the University of Malta and Mater Dei Hospital who studies the genetics of a similar blood disorder says, “This study is extremely important. It replicates in a living organism data that might be useful to deliver new drugs for the treatment of sickle cell disease and other blood disorders.” But, he cautions that turning off BCL11A could have unintended consequences with other blood types that could lead to complications not found in the study. He says, “Mice are mice and men are men.”
The study is published in the journal Science.
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