Correction of Nonsense Mutations in Cystic Fibrosis
ConditionCystic Fibrosis
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age8+
SponsorUniversity Hospital, Lille
About this trial
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.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
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
Disqualifiers
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
Trial population
Patients with cystic fibrosis and carry a nonsense mutation on the 2 alleles of the gene coding for the CFTR channel.
Trial design
Design model
Case-control
Time perspective
Prospective
Treatments tested in this trial
smear of nasal fossae
Other intervention1 smear of nasal fossae during a usual or scheduled visit
Treatment groups
No treatment groups listed
Trial outcomes
Primary outcomes
1
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
Time frame
less than 48hrs after the collect.Secondary outcomes
1
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
Time frame
an average 12 months2
Expression of the CFTR gene at the mRNA and protein level
Time frame
less than 1 week.Sponsors and contacts
Click on the lead sponsor to view all of their trials.
University Hospital, Lille
Lead sponsor
Vaincre la Mucoviscidose
Collaborator
Source ClinicalTrials.gov