|RNAi Therapy Works in Animal Models
Scott Harper et al. recently demonstrated that RNA interference (RNAi) can treat Huntington disease in an animal model (Harper et al., 2005). This work, together with a previous published experiment from the same group on treatment of spinal cerebellar ataxia (Xia et al., 2004), and two other experiments on treatment of ALS (Ralph et al., 2005; Raoul et al., 2005), demonstrates the concept of RNAi therapy for neurodegenerative diseases.
The common approach in these experiments was to deliver RNAi using viral vectors. All showed in vivo knockdown of the target gene and phenotypic improvement. These are very encouraging developments that bring RNAi one step closer to clinical application. Here I provide some background about these experiments and discuss some challenges that we still need to meet in order to realize the full therapeutic potential of RNAi.
In general, genetic disorders can be caused by two types of genetic mutations. One causes the gene to lose its function and the other causes the gene to gain a function—the gain...