Rewriting Our DNA

Cas9 is a DNA-cutting enzyme found in bacterial immune systems that defend bacteria against invading viruses. In Feng Zhang’s laboratory, researchers have adapted a complex containing this enzyme to edit the genome of animal cells. A leader in the development of the CRISPR-Cas9 technology, Zhang is the W.M. Keck Career Development Professor of Biomedical Engineering in MIT’s Departments of Brain and Cognitive Sciences and Biological Engineering, and a member of both the Broad Institute and McGovern Institute. This new genome-editing technology—which allows scientists to make precise changes in a sequence of DNA—has transformed many areas of biomedical research and may ultimately form the basis of new treatments for human genetic disease.

The CRISPR-Cas9 technology is engineered with molecular machinery that scientists can harness to make precise changes to the genome of animal and plant cells. The system enables rapid, functional screens of the entire genome, and allows scientists to identify genes involved in specific diseases. Zhang and his colleagues have already used CRISPR-Cas9 technology to identify genes that make some melanoma tumor cells resistant to drug therapy.

The Zhang laboratory continues to expand the CRISPR-Cas9 toolbox and to implement this technology to locate genes that could be manipulated to correct the effects of autism and other neurodegenerative diseases, including Alzheimer’s. Zhang is convinced that the technology—which his lab has shared with tens of thousands of other researchers—could also serve as a platform to accelerate the study of disease mechanisms, to discover new drug targets, and to develop a new generation of therapies that can directly perform surgery on the genomes of patients.