Therapeutic approaches for nonsense mutations in CFTR

Area of Science:

• Molecular Biology
• Genetics
• Pharmacology

Background:

• Nonsense mutations in the CFTR gene result in premature termination codons (PTCs), leading to truncated, non-functional proteins and transcript degradation via nonsense-mediated decay (NMD).
• Readthrough strategies aim to enable the synthesis of full-length functional proteins by facilitating amino acid incorporation at PTCs.

Purpose of the Study:

• To review recent advancements in readthrough strategies for suppressing nonsense mutations in the CFTR gene.
• To highlight three promising therapeutic approaches: small-molecule compounds, suppressor tRNAs, and readthrough-inducing antisense oligonucleotides (R-ASOs).

Main Methods:

• High-throughput screening to identify novel small-molecule compounds with reduced off-target effects.
• Development and delivery strategies for exogenous suppressor tRNAs designed to decode PTCs.
• Design of R-ASOs targeting complementary regions downstream of PTCs to induce readthrough.

Main Results:

• Novel small-molecule compounds, including aminoglycoside derivatives, show potential with fewer off-target effects.
• Suppressor tRNAs and their delivery systems are under active investigation for high readthrough efficiency.
• R-ASOs demonstrate feasibility in preclinical studies for readthrough of disease-causing CFTR mRNAs.

Conclusions:

• The three reviewed readthrough strategies show preclinical feasibility for treating CFTR nonsense mutations.
• Further optimization of delivery, pharmacokinetics, and minimization of off-target effects are crucial for human translation.
• Future research should address potential readthrough at normal stop codons to ensure safety.