Richmond, Va. (June 20, 2011) Researchers at Virginia Commonwealth University Massey Cancer Center have revealed novel mechanisms in mitochondria that have implications for cancer as well as many other age-related diseases such as Parkinson's disease, heart disease and hypertension. This discovery has pioneered the formation of a whole new field within epigenetics research ripe with possibilities of developing future gene therapies to treat cancer and age-associated diseases.
Shirley M. Taylor, Ph.D., researcher at VCU Massey Cancer Center and associate professor in the VCU Department of Microbiology and Immunology at VCU School of Medicine, was a graduate student when her research helped establish the field of epigenetics. Epigenetics refers to the process that controls which genes get expressed in the nucleus of a cell, ultimately determining that cell's biological characteristics. Now decades later, Taylor and her colleagues have further expanded the field of epigenetics into a new area of research they created by discovering enzymes in mitochondria that were previously known to exist only in nuclei.
In mammals, all cells have two distinct genomes, which include all of an organism's hereditary information. One set exists in the nucleus while the other exists in the mitochondrion, the energy generator of the cell.
Published in the journal Proceedings of the National Academy of Sciences (PNAS), Taylor's study found two DNA modifications in the mitochondrial genome: methylated cytosine, known to function in the nucleus by "silencing" the expression of certain genes; and hydroxymethyl cytosine, which removes the silencing mark imposed by the cytosine methylation.
Together, these modifications act like a genetic on/off switch in a process known as DNA methylation. Taylor's team also showed that the enzyme responsible for DNA methylation was present in mammalian mitochondria. The presence of these DNA modifications
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Virginia Commonwealth University