CAMBRIDGE, Mass. (December 1, 2007) — Damaged or defective genes have long been known to be the cause of some cancers. Over the past decade, however, scientists have discovered that even healthy genes can be switched on or off and can cause cancer without any changes in the underlying DNA sequence—although how this happens has remained poorly understood.Researchers in the laboratory of Whitehead Member Rudolf Jaenisch now have established a direct causal connection between hypermethylation (the accumulation of too many methyl molecules on regions of DNA) and the development of colon tumors in mice.
