New Gene-Editing Technology Successfully Cures a Genetic Blood Disorder in Mice

This article describes how Carnegie Mellon University and Yale University scientists have successfully cured a blood disorder in mice using a next generation gene editing system to significantly decrease the amount of unwanted genetic mutations that cause the blood disorder. This is said to be applicable to disorders such as sickle cell and beta thalassemia by affecting hematopoietic stem cells. Carnegie Mellon's Center for Nucleic Acids Science and Technology (CNAST) developed this peptide nucleic acid that runs the entire gene editing system.   

This new systen uses what an FDA approved nano-particle to deliver the peptide nucleic acid shown above along with another donor DNA to repair any genes that are malfunctioning. This is a big step from the old "CRISPR" system that is currently being used. Another problem solved is that these peptide nucleic acids are made to open up the DNA backbone and find a highly specific target without cutting anything. The CRISPR method used restriction enzymes to cleave the DNA. This poses problems for live animals and nonspecific cutting. A donor strand of DNA is required to replace any pieces of DNA that are taken out. This donor strand could be the sequence for a perfectly functioning HBB gene (hemoglobin sub-unit beta gene) and a stem cell factor that enhances the gene editing. All of the testing has been done on mouse and human bone marrow stem cells but has recently injected intravenously to mice with beta thalassemia. The results were an astounding 7% successful gene editing which is up from the .1% it used to be. The researchers designed these peptide nucleic acids with a polyethylene glycol side chain which makes the molecule water soluble. The stereochemistry from the side chain promotes a right handed helix allowing it to bind more readily to DNA.