Clues Found in the Study of Epigenomic Stability

There's new evidence implicating the role of siRNA in abnormal development of immortalized cell cultures. In a study published today, and led by scientists at Cold Spring Harbor Laboratory (New York), causes of genetic and epigenetic instability in plant cells grown in culture, were investigated. Patterns of DNA hyper- and hypomethylation were linked to expression of transposable elements (TEs) and their association with 21-nucleotide or 24-nucleotide siRNA molecules. Reactivation of silenced TEs, caused by irregular siRNA or other signals, can result in abnormal development of the plant. These results suggest that siRNA may plan a role in abnormal epigenetic signals which impede our use of immortalized cell cultures in stem cell therapies.

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Tanurdzic, M. et al. Epigenomic consequences of immortalized plant cell suspension culture. PLOS Biology, Dec. 9, 2008.