The process that alters gene expression and behavior without changing a gene's DNA sequence is called methylation. Plass, who is also part of the human cancer genetics program at Ohio State, studies methylation in both normal and cancer cells in hopes of better understanding how the process affects the beginning and progression of the disease.
"Methylation is important for normal cellular development," Plass said. "It can help protect the integrity of a DNA sequence. But certain changes in the regulation of DNA methylation could have fatal consequences for a cell or individual."
Identical twins are born with an identical set of genes. Studying genetic differences in twins may give Plass and his colleagues insight into how methylation is regulated.
"One would expect identical twins to develop and express genes at the same levels, but in fact this changes over time," Plass said. "We think that methylation plays a genome-wide role in these changes."
Scientists think that foods, exposure to chemicals, physical activity levels and aging may all contribute to methylation in cells. But they don't understand how changes in DNA methylation occur, or how the process is regulated.
The DNA analysis in this study showed that twins who had spent less of their lives together, or had greater differences in their health and medical histories, had the greatest amount of methylation.
The next step for Plass is to compare the findings of this study to what he sees in cancer cell cultures in his laboratory.
"Nearly every tumor, every human malignancy shows changes in DNA methylation that mess up gene expression," he said. "If we understand what regulates methylation patterns, then we may be able to develop better treatment options for cancer."
The researchers received financial support for this work from the Foundation
Source:Ohio State University