Correction of Nonsense Mutations in Cystic Fibrosis

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

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.

Study Overview

• Status: Recruiting
• Conditions: Cystic Fibrosis
• Intervention / Treatment: Other: smear of nasal fossae

• Study Type: Observational
• Enrollment (Anticipated): 85

Contacts and Locations

• Study Contact: Name: Anne Prévotat, MD; Phone Number: +33 03 20 44 59 48; Email: anne.prevotat@chru-lille.fr
• Study Contact Backup: Name: Fabrice Lejeune, PhD; Email: fabrice.lejeune@inserm.fr

Study Locations

• France
  • Amiens, France
    • Recruiting
    • Camsp Chu Amiens
  • Bron, France
    • Recruiting
    • Hopital Femme Mere Enfant - Hcl - Bron
  • Lille, France
    • Recruiting
    • Hôpital Calmette,CHU
    • Principal Investigator: Anne Prévotat, MD
  • Marseille, France
    • Recruiting
    • Aphm Hopital La Timone - Marseille
  • Montpellier, France
    • Recruiting
    • CHU Montpellier
  • Paris, France
    • Recruiting
    • Cmp Enfants Aphp Robert Debre - Paris
  • Paris, France
    • Recruiting
    • Hu Paris Centre Site Cochin Aphp - Paris 14
  • Strasbourg, France
    • Recruiting
    • Hopitaux Universitaires de Strasbour

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 8 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients with cystic fibrosis and carry a nonsense mutation on the 2 alleles of the gene coding for the CFTR channel.

Description

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

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Transport of iodide ions through the CEVAS membrane	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	less than 48hrs after the collect.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Immortalization of patient cells	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	an average 12 months
Expression of the CFTR gene at the mRNA and protein level		less than 1 week.

Collaborators and Investigators

• Sponsor: University Hospital, Lille
• Collaborators: Vaincre la Mucoviscidose

Study record dates

Study Major Dates

• Study Start (Actual): February 3, 2016
• Primary Completion (Anticipated): January 1, 2030
• Study Completion (Anticipated): January 1, 2030

Study Registration Dates

• First Submitted: August 1, 2018
• First Submitted That Met QC Criteria: September 11, 2018
• First Posted (Actual): September 13, 2018

Study Record Updates

• Last Update Posted (Actual): November 18, 2020
• Last Update Submitted That Met QC Criteria: November 17, 2020
• Last Verified: October 1, 2020

More Information

Terms related to this study

• Keywords: Cystic fibrosis; nonsense mutations; CFTR gene; nasal epithelial cells; nonsense mutation readthrough
• Additional Relevant MeSH Terms: Digestive System Diseases; Pathologic Processes; Respiratory Tract Diseases; Lung Diseases; Infant, Newborn, Diseases; Genetic Diseases, Inborn; Pancreatic Diseases; Fibrosis; Cystic Fibrosis
• Other Study ID Numbers: 2013_59; 2014-A01236-41 (Other Identifier: ID-RCB number, ANSM)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No