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Drug‐induced readthrough of premature stop codons leads to the stabilization of laminin α2 chain mRNA in CMD myotubes
Author(s) -
Allamand Valérie,
Bidou Laure,
Arakawa Masayuki,
Floquet Célia,
Shiozuka Masataka,
PaturneauJouas Marion,
Gartioux Corine,
ButlerBrowne Gillian S.,
Mouly Vincent,
Rousset JeanPierre,
Matsuda Ryoichi,
Ikeda Daishiro,
Guicheney Pascale
Publication year - 2008
Publication title -
the journal of gene medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.689
H-Index - 91
eISSN - 1521-2254
pISSN - 1099-498X
DOI - 10.1002/jgm.1140
Subject(s) - nonsense mutation , myogenesis , laminin , congenital muscular dystrophy , messenger rna , nonsense mediated decay , context (archaeology) , stop codon , biology , duchenne muscular dystrophy , gene , translation (biology) , mutation , genetics , microbiology and biotechnology , rna , extracellular matrix , paleontology , missense mutation , rna splicing
Abstract Background The most common form of congenital muscular dystrophy is caused by a deficiency in the α2 chain of laminin‐211, a protein of the extracellular matrix. A wide variety of mutations, including 20 to 30% of nonsense mutations, have been identified in the corresponding gene, LAMA2 . A promising approach for the treatment of genetic disorders due to premature termination codons (PTCs) is the use of drugs to force stop codon readthrough. Methods Here, we analyzed the effects of two compounds on a PTC in the LAMA2 gene that targets the mRNA to nonsense‐mediated RNA decay, in vitro using a dual reporter assay, as well as ex vivo in patient‐derived myotubes. Results We first showed that both gentamicin and negamycin promote significant readthrough of this PTC. We then demonstrated that the mutant mRNAs were strongly stabilized in patient‐derived myotubes after administration of negamycin, but not gentamicin. Nevertheless, neither treatment allowed re‐expression of the laminin α2‐chain protein, pointing to problems that may have arisen at the translational or post‐translational levels. Conclusions Taken together, our results emphasize that achievement of a clinical benefit upon treatment with novel readthrough‐inducing agents would require several favourable conditions including PTC nucleotide context, intrinsic and induced stability of mRNA and correct synthesis of a full‐length active protein. Copyright © 2007 John Wiley & Sons, Ltd.