CRISPR: Human Genome Editing Just Got Easier
By Ahmad Sabbagh '17
The celebrated yet controversial CRISPR gene-editing technique has become more efficient and feasible to use thanks to the discovery of a mini enzyme by researchers from the Broad Institute of MIT and Harvard. Scientists hope to apply the newly improved CRISPR method in treating human genetic defects and maladies.
The CRISPR method, which researchers had already been using to correct genome defects in animal embryos, was limited in use to human genomes due to the large size of the gene-editing enzyme Cas9 and its guiding RNA molecules. The newly discovered Cas9 enzyme extracted from the bacterium Staphylococcus aureus is over 1,000 DNA letters smaller than the currently used Cas9 enzyme from Streptococcus pyogenes, allowing for easier mobility and more efficient transport between human body cells. Gene-editing using the new, smaller enzyme has proved to be effective, allowing for the same accuracy in results as the S. pyogenes enzyme.
Despite its rapid development and successes on animal specimen, the CRISPR technology will need some time before it is brought to clinics to treat human diseases and will probably experience some setbacks as it continues to develop. The immediate results of the new improvement in CRISPR, however, are promising, as it adds new tools to the genome-editing toolbox. According to Feng Zhang, lead researcher of the team that discovered the new enzyme, the improved CRISPR method will help “create better models of disease, identify mechanisms, and develop new treatments.”
The promising prospects of gene-editing also bring with them concerns pertaining to issues of ethical and safety practices. Besides curing diseases, gene-editing could be utilized to enhance desirable qualities in embryo genomes. This brings forth an issue of ethics, as the modified genes would be passed on to generations of humans without the consent of those effected. It also raises an issue of safety, as mutations may occur at locations other than those targeted, creating unintended consequences and potentially causing disease. These concerns have led to a group of biologists, including the inventor of CRISPR, to call for a worldwide moratorium on such modifications to human embryos. With power comes responsibility, urging the controlled use of such powerful technology, lest our urge for control of the future spiral our future out of control.
Sources:
http://www.scientificamerican.com/article/new-discovery-moves-gene-editing-closer-to-use-in-humans/
http://www.nature.com/news/mini-enzyme-moves-gene-editing-closer-to-the-clinic-1.17234
http://www.nature.com/news/ethics-of-embryo-editing-divides-scientists-1.17131