Treating Genetic Disorders Before Birth
A 14-day-old mouse embryos (shown here in an ultrasound), researchers have shown that genetic blood disorders might be treatable before birth.
Credit: Journal of Clinical Investigation
1)Researchers are working on transplantingstem cells in utero.
Physicians may one day be able to treat genetic blood diseases before a child is even born. In a study of mice that was published this week in the Journal of Clinical Investigation, researchers at the University of California, San Francisco, have found that transplanting a mother's own stem cells into her fetus populates its bone marrow with healthy cells while avoiding immune rejection.
If the findings hold true in humans, stem-cell transplants from mother to fetus could prime the fetus for a bone-marrow transplant from its mother—or a donor that is tissue-matched to the mother—after birth.
Diseases such as sickle cell anemia and beta thalassemia result from abnormal red blood cells and can be treated with bone-marrow transplants. But it's not always possible to find a match. And standard bone-marrow transplants, even between tissue-matched donors, must be followed with a lengthy course of immunosuppressive drugs.
Scientists theorize that bone-marrow transplants performed when a fetus is still developing would override this problem. They suspect that the fetus's immature immune system could be tricked into adopting those foreign cells and recognizing them as its own. "The fetus is wired to tolerate cells—when it encounters cells from mom, it tolerates them," says Tippi MacKenzie, the pediatric surgeon at UCSF who led the new research.
Physicians may one day be able to treat genetic blood diseases before a child is even born. In a study of mice that was published this week in the Journal of Clinical Investigation, researchers at the University of California, San Francisco, have found that transplanting a mother's own stem cells into her fetus populates its bone marrow with healthy cells while avoiding immune rejection.
If the findings hold true in humans, stem-cell transplants from mother to fetus could prime the fetus for a bone-marrow transplant from its mother—or a donor that is tissue-matched to the mother—after birth.
Diseases such as sickle cell anemia and beta thalassemia result from abnormal red blood cells and can be treated with bone-marrow transplants. But it's not always possible to find a match. And standard bone-marrow transplants, even between tissue-matched donors, must be followed with a lengthy course of immunosuppressive drugs.
Scientists theorize that bone-marrow transplants performed when a fetus is still developing would override this problem. They suspect that the fetus's immature immune system could be tricked into adopting those foreign cells and recognizing them as its own. "The fetus is wired to tolerate cells—when it encounters cells from mom, it tolerates them," says Tippi MacKenzie, the pediatric surgeon at UCSF who led the new research.
- Results of world's first gene therapy for inherited blindness show sight improvement. 28 April 2008. UK researchers from the UCL Institute of Ophthalmology and Moorfields Eye Hospital NIHR Biomedical Research Centre have announced results from the world’s first clinical trial to test a revolutionary gene therapy treatment for a type of inherited blindness. The results, published today in the New England Journal of Medicine, show that the experimental treatment is safe and can improve sight. The findings are a landmark for gene therapy technology and could have a significant impact on future treatments for eye disease.
Previous information on this trial (May 1, 2007): A team of British doctors from Moorfields Eye Hospital and University College in London conduct first human gene therapy trials to treat Leber's congenital amaurosis, a type of inherited childhood blindness caused by a single abnormal gene. The procedure has already been successful at restoring vision for dogs. This is the first trial to use gene therapy in an operation to treat blindness in humans.
- A combination of two tumor suppressing genes delivered in lipid-based nanoparticles drastically reduces the number and size of human lung cancer tumors in mice during trials conducted by researchers from The University of Texas M. D. Anderson Cancer Center and the University of Texas Southwestern Medical Center.
- Researchers at the National Cancer Institute (NCI), part of the National Institutes of Health, successfully reengineer immune cells, called lymphocytes, to target and attack cancer cells in patients with advanced metastatic melanoma. This is the first time that gene therapy is used to successfully treat cancer in humans.
- Gene therapy is effectively used to treat two adult patients for a disease affecting nonlymphocytic white blood cells called myeloid cells. Myeloid disorders are common and include a variety of bone marrow failure syndromes, such as acute myeloid leukemia. The study is the first to show that gene therapy can cure diseases of the myeloid system.
- Gene Therapy cures deafness in guinea pigs. Each animal had been deafened by destruction of the hair cells in the cochlea that translate sound vibrations into nerve signals. A gene, called Atoh1, which stimulates the hair cells' growth, was delivered to the cochlea by an adenovirus. The genes triggered re-growth of the hair cells and many of the animals regained up to 80% of their original hearing thresholds. This study, which many pave the way to human trials of the gene, is the first to show that gene therapy can repair deafness in animals.
- University of California, Los Angeles, research team gets genes into the brain using liposomes coated in a polymer call polyethylene glycol (PEG). The transfer of genes into the brain is a significant achievement because viral vectors are too big to get across the "blood-brain barrier."
- RNA interference or gene silencing may be a new way to treat Huntington's. Short pieces of double-stranded RNA (short, interfering RNAs or siRNAs) are used by cells to degrade RNA of a particular sequence. If a siRNA is designed to match the RNA copied from a faulty gene, then the abnormal protein product of that gene will not be produced.
- New gene therapy approach repairs errors in messenger RNA derived from defective genes. Technique has potential to treat the blood disorder thalassaemia, cystic fibrosis, and some cancers.
- Gene therapy for treating children with X-SCID (sever combined immunodeficiency) or the "bubble boy" disease is stopped in France when the treatment causes leukemia in one of the patients.
- Researchers at Case Western Reserve University and Copernicus Therapeutics are able to create tiny liposomes 25 nanometers across that can carry therapeutic DNA through pores in the nuclear membrane.
- Sickle cell is successfully treated in mice.