Hit&Run – the Italian way to epi-editing

The San Raffaele-Telethon Institute in Milan has been a leading player in gene therapy for many years. Nowadays, Angelo Lombardo, Luigi Naldini, and colleagues are making news with epigenetic editing. Their 2016 paper in Cell on hit-and-run epigenetic editing is considered seminal work. The company they co-founded, Chroma Medicine, received substantial financing, as recently reported by Nature Biotechnology. Last but not least, the presentation given in May at the annual meeting of the American Society of Gene and Cell Therapy inspired a Science news entitled “Better than CRISPR? Another way to fix gene problems may be safer and more versatile.” In brief, they injected mice to silence the expression of the PCSK9 gene, lowering “bad” cholesterol levels for months

CRISPR Ikea-style

Modular design is the latest trend for developing new CRISPR tools. In The CRISPR Journal, Juan Carlos Collantes et al. present a base-editor system called Pin-point that recruits a DNA base-modifying enzyme through a hook (an RNA aptamer) within the guide-RNA molecule. In Nature Communications the goal of Lacramioara Bintu and colleagues is not base editing but epigenomic editing, the effector is a chromatin regulator and the hook is an antibody. When the CRISPR-effector combo is big, delivery of individual modules is easier. Furthermore, if the effector is already present inside the cell it can be simply recruited by providing the right hook. One more potential advantage is the convenient reconfiguration of the system by the mix and match of individual components and simultaneous recruitment of different effectors to different target sites.

Epigenetic editing hits hat-trick

editing epigenetico Cell

Reversing three genetic diseases in the animal model without even changing a single DNA letter. A Salk Institute team did it by bringing together two of biomedicine’s hottest trends. One is the CRISPR technique, which edits target genes through a programmable molecular machine named Cas9. The other is epigenetics, i.e., the study of chemical modifications that switch genes on and off without altering their sequence. It’s called epigenetic editing, because corrections are precise as in manuscript revision and occur at a level that is over (epi- in Greek) genetics. Continue reading