April 2 (UPI) — Researchers in Australia have found a way to introduce natural mutations into blood cells that could lead to new therapies for sickle cell anemia and other blood disorders.
University of New South Wales scientists used gene editing to introduce the mutations into blood cells as a way to boost fetal hemoglobin production. The mutations that cause the disorders are naturally carried by a small percentage of people, but the highly individualized method could help treat some of them.
The research was published Monday in the journal Nature Genetics.
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats, which serves as the bacterial defense system that forms the basis for genome editing technology.
Sickle cell anemia and beta thalassemia are highly prevalent where malaria has been present, including South East Asia, southern China and India, South America, Africa, the Mediterranean and the Middle East. And the diseases can be found in countries with migration of populations, including Australia and the United States.
Sickle cell disease affects approximately 100,000 Americans, including about 1 out of every 365 black births, according to the Centers for Disease Control and Prevention. About 1 in 13 black babies is born with the sickle cell trait.
People with thalassaemia or sickle cell anemia require life-long treatment with blood transfusions and medications because of the defective adult hemoglobin, the vital molecule that picks up oxygen in the lungs and transports it around the body.
Nobel Laureate Linus Pauling first determine that sickle cell disease was due to a change in an amino acid in a protein. Fred Sanger, also a Nobel Laureate, identified the genetic mutation that causes the condition.
Researchers in Australia now say they have solved a 50-year-old mystery about how these mutations work and alter human genes.
Some people have reduced symptoms because they carry mutations, which switch on the gene that produces fetal hemoglobin. It compensates for their damaged adult hemoglobin.
“Our new approach can be seen as a forerunner to ‘organic gene therapy’ for a range of common inherited blood disorders including beta thalassaemia and sickle cell anemia,” author Dr. Merlin Crossley, who is a scientist at University of South Wales. “It is organic because no new DNA is introduced into the cells; rather we engineer in naturally occurring, benign mutations that are known to be beneficial to people with these conditions.”
This can lead to new treatments, the researcher says.
“It should prove to be a safe and effective therapy, although more research would be needed to scale the processes up into effective treatments,” Crossley said.
The two genes that switch off the fetal hemoglobin gene by binding directly to it are called BCL11A and ZBTB7A.
“The beneficial mutations work by disrupting the two sites where these two genes bind,” Crossley said. “This landmark finding not only contributes to our appreciation of how these globin genes are regulated. It means we can now shift our focus to developing therapies for these genetic diseases using CRISPR to target precise changes in the genome.”
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