THE FATE OF INDIVIDUAL MYOBLASTS AFTER TRANSPLANTATION INTO MUSCLES OF DMD PATIENTS

Muscle biopsies from six patients with Duchenne muscular dystrophy (DM D) participating in a myoblast transplantation clinical trial were ree xamined using a fluorescence in situ hybridization (FISH)-based method . Donor nuclei were detected in all biopsies analyzed, including nine where no donor myoblasts were previously thought to be present. In thr ee patients, more than 10% of the original number of donor cells were calculated as present 6 months after implantation. Half of the detecte d donor nuclei were fused into host myofibers, and of these, nearly 50 % produced dystrophin. These findings demonstrate that although donor myoblasts have persisted after injection, their microenvironment influ ences whether they fuse and express dystrophin. Our methodology could be used for developing new approaches to improve myoblast transfer eff icacy and for the analysis of future gene-and/or cell-based therapies of numerous genetic disorders.