View Full Version : Current research in Epigenetics

11-12-05, 11:04 AM

"Epigenetic modifications, or marks, involve the addition of certain molecules, such as methyl groups, to the backbone of the DNA molecule, leading to a variety of effects. Such modifications can change the way in which genes in the neighborhood of the mark interact with the transcriptional machinery that turns genes on or off, thereby spurring or preventing the production of the proteins that those genes encode.

Also, for certain genes, the addition of methyl groups serves to distinguish between the gene copy inherited from the father and the one inherited from the mother - a situation referred to as imprinting. For some genes, only the paternally imprinted copy is activated to produce proteins and for others, only the maternally imprinted copy is used. Paternally expressed imprinted genes generally code for proteins that promote cell growth, while maternally expressed imprinted genes play a role in suppressing cell growth.

Consequently, the gain or loss of such epigenetic marks can lead to cancer and other diseases by upsetting the cell's normal growth cycle. There is also evidence in mice that some imprinted genes may play a role in behavior.

The interdisciplinary team led by Dr. Feinberg, who has pioneered the study of epigenetics in cancer, will develop tools to create comprehensive, genome-wide information about epigenetics and then apply that information to the study of autism and bipolar disorder.

"Epigenetics doesn't underlie all human disease. But it may be as important in certain conditions as the DNA sequence is in other cases," said Dr. Feinberg. "We definitely need to develop the technology to figure out when and where epigenetic changes do influence health and disease."

Among the first items on the researchers' to-do list is the development of technologies to speed identification of epigenetic marks and their locations across the entire human genome - to essentially create a map of the "epigenome." Next, in collaboration with researchers from Pennsylvania State University in University Park, Pa.; Epigenomics, Inc., of Berlin; and the Icelandic Heart Foundation, Feinberg's team will use the new technologies to examine the epigenomes of families involved in ongoing studies of autism and bipolar disorder. Also participating in the center's work are two NIH researchers: Eric Green, M.D., Ph.D., director of NHGRI's Division of Intramural Research, and Tamara Harris, M.D., M.S., chief of the Geriatric Epidemiology Section at the National Institute on Aging".