Correction of Nonsense Mutations in Cystic Fibrosis

Sponsor

University Hospital, Lille (Other)

Overall Status

Recruiting

CT.gov ID

NCT03670472

Collaborator

Vaincre la Mucoviscidose (Other)

Enrollment

Locations

166.9

Anticipated Duration (Months)

10.6

Patients Per Site

0.1

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The presence of a nonsense mutation leads to the rapid degradation of the carrier mRNA mutation by a mechanism called NMD (nonsense-mediated mRNA decay) [6, 13]. There are currently 3 main strategies at least for correcting nonsense mutations: exon skipping, inhibition of NMD and nonsense mutation readthrough.

In the laboratory, we developed a strategy for correcting nonsense mutations combining inhibition of NMD and activation of translecture. For this purpose, we have constructed screening systems to identify NMD-inhibiting and/or readthrough enhancers. The molecules thus identified are then tested on cell lines and in murine models carrying a nonsense mutation.

One of our goals is to select a set of molecules that can correct effectively nonsense mutations. For this we have to test these molecules on a great diversity of nonsense mutations.

This work will:

determine if we can correct all the nonsense mutations tested with at least one of our molecules
determine what is common within a group of mutations corrected by a given molecule
be able to assign the parameters that make one mutation is corrected by one molecule and not or little by another.

This study will therefore improve our theoretical knowledge on the recognition of premature stop codons but also to propose therapeutic approaches for the correction of nonsense mutations of the CFTR gene in cystic fibrosis in a targeted way for a patient.

Condition or Disease	Intervention/Treatment	Phase
Cystic Fibrosis	Other: smear of nasal fossae

Study Design

Study Type:

Observational

Anticipated Enrollment :

85 participants

Observational Model:

Case-Control

Time Perspective:

Prospective

Official Title:

Optimization of Correcting Molecules of Nonsense Mutations in Epithelial Cells of the Upper Airways of Patients With Cystic Fibrosis With Nonsense Mutations in the CFTR Gene

Actual Study Start Date :

Feb 3, 2016

Anticipated Primary Completion Date :

Jan 1, 2030

Anticipated Study Completion Date :

Jan 1, 2030

Outcome Measures

Primary Outcome Measures

Transport of iodide ions through the CEVAS membrane [less than 48hrs after the collect.]
Patient cells with be cultured in BEGM (Lonza) medium and incubated with corrector of nonsense mutations for 20 hours and with a fluorescent molecule called SPQ (for 6-methoxy-N-3'-sulfopropylquinolinium). Iodine can bind SPQ and will quench the SPQ fluorescence. Nitrates bind SPQ without quenching SPQ fluorescence. By placing patient cells first into an iodine-rich medium to quench the SPQ fluorescence and second into a nitrate-rich medium, we will be able to measure the level of functional CFTR protein present in these cells by measuring the re-apparition of fluorescence using fluorimeter. Indeed, nitrate will be able to replace iodine on SPQ without quenching SPQ fluorescence only if iodine exits cells through CFTR channels. This assay allows determining whether a corrector of nonsense mutation is able to lead to the synthesis of functional CFTR protein

Secondary Outcome Measures

Immortalization of patient cells [an average 12 months]
Immortalization of patient cells will be attempted by transfection of construct expressing the origin-of-replication defective SV40 as described in Gruenert et al.,2004
Expression of the CFTR gene at the mRNA and protein level [less than 1 week.]

Eligibility Criteria

Criteria

Ages Eligible for Study:

8 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Male / female adults and minors aged 8 years and over
Patients with cystic fibrosis and carry a nonsense mutation on the 2 alleles of the gene coding for the CFTR channel.
Patients whose genotype of patients concerning the CFTR gene is known.
Patients with social security
Major patients who have given their consent
Minor patients with parental authorization

Exclusion Criteria:

Patients who have a mutation other than nonsense in the CFTR gene
Patients whose CFTR gene was not sequenced on the 2 alleles
Patients not wishing to participate in this study or persons not giving or not able to give consent.
Pregnant or lactating women
Patients under curatorship or guardianship

Contacts and Locations

Locations

	Site	City	Country
1	Camsp Chu Amiens	Amiens	France
2	Hopital Femme Mere Enfant - Hcl - Bron	Bron	France
3	Hôpital Calmette,CHU	Lille	France
4	Aphm Hopital La Timone - Marseille	Marseille	France
5	Chu Montpellier	Montpellier	France
6	Cmp Enfants Aphp Robert Debre - Paris	Paris	France
7	Hu Paris Centre Site Cochin Aphp - Paris 14	Paris	France
8	Hopitaux Universitaires de Strasbour	Strasbourg	France