Progress Update: Base editing of DUX4 somatic polyadenylation signal

Progress report by Darina Šikrová

In the past 6 months we continued to study the effect of disrupting the DUX4 polyadenylation signal (PAS), a signal that instructs the cell to stabilize the DUX4 RNA molecule, in muscle cells derived from different FSHD affected individuals to confirm the universality of such approach in reducing the DUX4 RNA molecules production in muscle cells.

We also continued with the second aim of our project – creating new versions of our editing tool, which we use to carry out highly efficient disruption of the DUX4 PAS. Unfortunately, the new versions were inferior compared to original editor in their activity. Therefore, we had to also modify our experimental design for studies which we proposed to do in our mouse model. This mouse model has a copy of the human DUX4 locus in its genome, which allows us to test the efficacy of our approach also in vivo. Originally, we wanted to use the help of viruses to deliver the editing components to skeletal muscle tissue, however, the size of the editor is incompatible with the load capacity of viruses which are commonly used for such purpose. We now plan on a new delivery which doesn’t rely on viral delivery.

See grant Base editing of DUX4 somatic polyadenylation signal