1. ¹CNRS UMR 8621, Institut de Génétique et Microbiologie, Université Paris-Sud, Orsay Cedex, France
2. ²GENETHON, CNRS UMR 8115, Evry, France
3. ³INSERM U582-Institut de Myologie, IFR14, Groupe Hospitalier Pitié-Salpétrière, Paris Cedex, France
4. ⁴UMR955 INRA/ENVA de Génétique Moléculaire et Cellulaire, Ecole Nationale Vétérinaire d'Alfort, 7, Maisons-Alfort Cedex, France

Correspondence: J-P Rousset, CNRS UMR 8621, Institut de Génétique et Microbiologie, Université Paris-Sud, Orsay Cedex 91405, France

Received 30 June 2003; Accepted 10 November 2003; Published online 19 February 2004.

Abstract

The suppression levels induced by gentamicin on premature stop codons, caused by primary nonsense mutations found in muscular dystrophy patients, were assessed using a very sensitive dual reporter gene assay. Results show that: (i) the effect of gentamicin on readthrough is similar in cultured cells and in vivo in murine skeletal muscle; (ii) a wide variability of readthrough efficiency is obtained, depending on the mutation tested; (iii) due to the complexity of readthrough regulation, efficiency cannot be predicted by the nucleotide context of the stop codon; (iv) only a minority of premature stop codons found in patients show a significant level of readthrough, and would thus be amenable to this pharmacological treatment, given our present understanding of the problem. These results probably provide an explanation for the relative failure of clinical trials reported to date using gentamicin to treat diseases due to premature stop codons, and emphasize that preliminary assays in cell culture provide valuable information concerning the potential efficiency of pharmacological treatments.