Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease 
caused by homozygous deletions or mutations in survival motor neuron gene 1 
(SMN1). Currently, the primary therapeutic strategy for SMA is to increase the 
level of SMN via correcting SMN2 splicing (nusinersen and risdiplam). However, 
some patients with SMA do not respond to such treatments, thereby warranting a 
need to develop new therapeutic strategies. We have previously reported that 
SMN2 expression is epigenetically regulated by DNA methylation levels of the 
SMN2 promoter region. In the present study, we determined that 
methyl-CpG-binding protein 2 (MeCP2) may bind to this critical promoter region 
(nt-167 to 43). Antisense oligonucleotides (ASO-P1 and ASO-P2) were designed to 
target the key methylation sites in the SMN2 promoter region, which enhanced the 
overall transcription and functional protein expression levels in the SMA cell 
lines. These results were similar to those observed in nusinersen-treated SMA 
cells. Moreover, a combined treatment of ASO-P1 and ASO-NUS in SMA cell lines 
further increases fl-SMN2 transcript and SMN protein levels. The delivery of 
ASO-P1 to the central nervous system of severe SMA mice corrected the molecular, 
pathological, and functional phenotypes of this disease and increased survival 
rates. Our findings suggest that the key methylation regions in the SMN2 
promoter region may be a novel therapeutic target for SMA.