Mismatched single stranded antisense oligonucleotides can induce efficient dystrophin splice switching

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Antisense oligomers (AOs) aim to treat Duchenne muscular dystrophy (DMD) by inducing exon skipping.
• Intra-exonic mutations can compromise AO efficiency, potentially requiring personalized AO design.
• The necessity of patient-specific AOs for all polymorphisms is unclear.

Purpose of the Study:

• To investigate the efficacy of standard splice-switching AOs in patient cells with intra-exonic mutations.
• To determine if patient-specific AO design is always necessary for intra-exonic DMD mutations.

Main Methods:

• Preclinical testing of splice-switching AOs targeting exon 25 of the dystrophin transcript.
• Utilized normal and DMD patient-derived cells harboring a single base insertion in exon 25.
• Compared the efficiency of a standard AO with a mutation-specific AO.

Main Results:

• A standard AO, designed for normal dystrophin mRNA, efficiently removed mutated exon 25.
• The standard AO demonstrated higher efficiency in excising exon 25 compared to the mutation-specific AO, despite the mismatch.
• This suggests that polymorphisms may not always impede AO function.

Conclusions:

• Standard antisense oligomers may be therapeutically applicable even in the presence of certain patient polymorphisms.
• This finding could negate the need for costly, patient-specific AO development in some DMD cases.
• Further research may validate the broader applicability of non-personalized AOs for exon skipping therapies.