Characterization of new-generation aminoglycoside promoting premature termination codon readthrough in cancer cells

ABSTRACT

Nonsense mutations, generating premature termination codons (PTCs), account for 10% to 30% of the mutations in tumor suppressor genes. Nonsense translational suppression, induced by small molecules including gentamicin and G418, has been suggested as a potential therapy to counteract the deleterious effects of nonsense mutations in several genetic diseases and cancers. We describe here that NB124, a synthetic aminoglycoside derivative recently developed especially for PTC suppression, strongly induces apoptosis in human tumor cells by promoting high level of PTC readthrough. Using a reporter system, we showed that NB124 suppressed several of the PTCs encountered in tumor suppressor genes, such as the p53 and APC genes. We also showed that NB124 counteracted p53 mRNA degradation by nonsense-mediated decay (NMD). Both PTC suppression and mRNA stabilization contributed to the production of a full-length p53 protein capable of activating p53-dependent genes, thereby specifically promoting high levels of apoptosis. This new-generation aminoglycoside thus outperforms the only clinically available readthrough inducer (gentamicin). These results have important implications for the development of personalised treatments of PTC-dependent diseases and for the development of new drugs modifying translation fidelity.

KEYWORDS:

• Aminoglycoside
• apoptosis
• cancer
• p53
• stop codon readthrough

Disclosure of potential conflicts of interest

Timor Baasov acknowledges that he is used by Technion who owns the patents relating to NB compounds discussed in this study, that were licensed to a third party.

Acknowledgments

We thank Alex Edelman & Associates for correcting English usage. We would like to thank our collaborators from Dundee University, especially Virginia Appleyard, Jean-Christophe Bourdon and Alastair Thompson, for their help and discussions during this project.

Funding

This project is supported by the French foundation ARC [SFI20101201647 and PJA 20131200234]; and the French association ‘Ligue Nationale contre le cancer’ [3FI10167LVCY and, grants awarded to O.N.].

Author contributions

L.B and O.B performed cell experiments, V.B and T.B designed and synthesized aminoglycoside derivatives. L.B, O.B, T.B and O.N designed the experiments. All the authors interpreted the data and participated in the writing of the manuscript.