Oligonucleotide-Based Therapy for FTD/ALS Caused by the C9orf72 Repeat Expansion: A Perspective

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• Amyotrophic lateral sclerosis (ALS) and Frontotemporal Dementia (FTD) are progressive neurodegenerative disorders with overlapping clinical, pathological, and genetic features.
• The C9orf72 gene hexanucleotide repeat expansion is a primary genetic cause of the FTD/ALS spectrum (c9FTD/ALS).
• Pathogenic mechanisms for c9FTD/ALS include C9orf72 loss-of-function and gain-of-function via RNA foci or protein aggregates.

Purpose of the Study:

• To explore the potential of antisense oligonucleotide (ASO) therapy for c9FTD/ALS.
• To discuss the mechanisms and challenges associated with developing ASO-based treatments for this disease spectrum.

Main Methods:

• Review of proposed pathogenic mechanisms in c9FTD/ALS (loss-of-function, gain-of-function).
• Evaluation of antisense oligonucleotide (ASO) technology for gene silencing and splice modulation.
• Analysis of ASO efficacy in other repeat expansion diseases.

Main Results:

• Antisense oligonucleotides (ASOs) are effective in repeat expansion diseases, suggesting potential for c9FTD/ALS.
• ASOs can target specific mRNAs to modulate gene expression, addressing both loss-of-function and gain-of-function mechanisms.

Conclusions:

• ASO therapy presents a viable therapeutic strategy for c9FTD/ALS.
• Further research is needed to overcome challenges in developing effective oligonucleotide-based treatments for c9FTD/ALS.