Wired News: Giving Genetic Disease the Finger:
...Scientists are closing in on techniques that could let them safely repair almost any defective gene in a patient, opening the door for the first time to treatments for a range of genetic disorders that are now considered incurable.
The breakthrough, announced in the journal Nature in June, relies on so-called zinc fingers, named after wispy amino acid protuberances that emanate from a single zinc ion. When inserted into human cells, the fingers automatically bind to miscoded strands of DNA, spurring the body's innate repair mechanism to recode the problem area with the correct gene sequence.
"This doesn't just deliver a foreign gene into the cell," said Nobel Prize winner and CalTech President David Baltimore, who with a Sangamo paper co-author Mathew Porteus proposed this method to cure genetic diseases. "It actually deletes the miscoded portion and fixes the problem."
At the heart of the breakthrough is the concept of "if it's broke, break it some more." Cells have a method of DNA repair called homologous recombination, which fixes breaks in the double helix of our chromosomes. But the process only repairs places where the DNA has been cut, not where genes have been miscoded.
Using a package of synthesized zinc fingers, cells can be tricked into doing nano-surgery on their own genes, Sangamo researchers found. The zinc fingers home in like a guided missile on the exact spot in the genome doctors are trying to target and then bind to it. DNA-devouring enzymes then cut through the double helix of DNA at the exact beginning and end of the targeted gene, and a template of donor DNA helps rebuild the deleted strand.
Posts
No comments:
Post a Comment