SHT - Sickle cell anemia cured in lab mice

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http://www.boston.com/news/daily/13/sickle_cell.htm

Gene therapy technique cures sickle blood disease in Harvard, MIT laboratory mice, a key step toward human therapy

By Paul Recer, Associated Press, 12/13/01

WASHINGTON -- Sickle cell anemia, a severe, inherited blood disorder that affects more than 70,000 Americans, was cured in laboratory mice using a modified HIV virus to transfer healthy genes into the animal's bone marrow stem cells.

Experts said the achievement, by a team led by Harvard Medical School and Massachusetts Institute of Technology researchers, marks "an important milestone" in using transferred genes to correct inherited diseases.

"It corrected the sickling problem throughout the bodies of these mice," said Philippe Leboulch, a Harvard and MIT scientist who led the team. "All of the mice were cured permanently."

Leboulch said more study was needed and that it would be at least two years before the technique would be ready for human experiments.

A report on the study appears Friday in the journal Science.

"This is an exciting result," said Dr. Michel Sadelain of the Memorial Sloan-Kettering Cancer Center in New York. "It is an important milestone in gene therapy."

Sadelain earlier achieved a similar success in mice by correcting the genetic flaw that causes thalassemia, a blood disorder related to sickle cell anemia.

In the new study, researchers used two types of mice that are bred to have a blood disease closely resembling the sickle cell anemia disease in humans.

They removed from the mice samples of the bone marrow, which makes blood, and then irradiated the mice to kill the remaining abnormal bone marrow.

Into the removed bone marrow cells, the researchers placed a fragment of the HIV virus that had been manipulated to contain a normal red blood cell gene. The virus infected the bone marrow, carrying the normal gene into each of the blood-making cells. The bone marrow was then reinjected into the mice.

Once in the animals, the genetically altered bone marrow cells produced normal red blood cells and corrected the sickling disease in the mice.

After 10 months, the mice were killed and their organs and blood examined.

Leboulch said there was no evidence of abnormal blood nor of the organ damage that is common with sickle cell anemia.

Both sickle cell anemia and thalassemia are caused by a failure of a gene that helps to make hemoglobin, the protein in red blood cells that carries oxygen.

In thalassemia, the gene fails to make enough hemoglobin.

In sickle cell disease, the gene makes an abnormal hemoglobin that is sticky and stiff. Instead of the soft, doughnut-shaped, normal hemoglobin, the abnormal protein often forms into a distinctive sickle shape with a sharp point. The abnormal hemoglobin tends to clog small vessels, blocking the flow of blood. This starves tissues for oxygen and can cause damage throughout the body.

The disease causes intense pain. It damages the liver, lungs and kidneys and can trigger stroke or infections. There is no cure, and treatment consists of combatting the symptoms with antibiotics, blood transfusions and surgery.

About 1.2 million Americans carry one sickle cell gene. They are said to have the sickle cell trait and are not affected by the disease. A person must inherit two sickle cell genes -- one from each parent -- to have the disease. A child born to two parents with the sickle cell trait has one chance in four of the disease. When one parent has the disease and one parent carries the trait, the chances of inheriting sickle cell disease is about 50 percent.

Sickle cell anemia is most common in people of African heritage, but it can occur in any race.

National Institutes of Health: http://www.rhofed.com/sickle/

Sickle Cell Disease Association of America: http://www.sicklecelldisease.org/

Science: http://www.eurekalert.org

-- Anonymous, December 13, 2001

Answers

Modified HIV virus? Sweet Jesus.

-- Anonymous, December 13, 2001

Peter,

My thoughts exactly! I think I'd do just about anything else buy try that option... :-(

-- Anonymous, December 13, 2001


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