RNA interference is an evolutionarily conserved mechanism of post-transcriptional gene silencing. Small interfering RNAs (siRNA) of 21-23 nucleotides generated from processing double-stranded RNA (dsRNA) by ribonuclease III, Dicer, are widely used for selective sequence-specific gene silencing in a broad range of organisms. In plants, siRNA is associated with de novo RNA-directed DNA methylation (RdDM) at the homologous target genomic region. To examine RdDM in somatic cells, human glioblastoma cell lines were treated with siRNAs homologous to the human huntingtin gene responsible for Huntington's disease. Methylation of CpG dinucleotides in the plasmid vectors expressing the dsRNAs and homologous genomic region was investigated by bisulfite-mediated genomic sequencing. Target regions of the siRNA in the huntingtin gene showed no significant change in the pattern of DNA methylation, and no CpG methylation was observed on the plasmid vectors. These results indicate that siRNA is not directly linked to DNA methylation at the target huntingtin genomic locus in human cells.
|Original language||English (US)|
|Number of pages||6|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Oct 8 2004|
Bibliographical noteFunding Information:
This research was supported in part by grants from the National Institutes of Health (P01 HL65578 and P01 HL55552), and the Alexander and Margaret Stewart Trust to C.J.S.
- Bisulfite sequencing
- CpG dinucleotides
- De novo DNA methylation
- Epigenetic modification
- Huntington's disease
- Neuronal cell culture
- Plant genetics
- Post-transcriptional gene silencing
- RNA interference