A Penn State-led research team has found that changes to proteins called histones, which are associated with DNA, can control whether or not a gene is allowed to function. The changes may be important in maintaining the genes' "expression potential" so that future cells behave as their parent cells did. The discovery, which may have implications for the study of diseases such as cancer, will be published in a print edition of the journal Proceedings of the National Academy of Sciences. The research was led by Lu Bai, an assistant professor of biochemistry, molecular biology, and physics at Penn State University, in collaboration with David Stillman at the University of Utah.
Bai explained that gene expression -- the process by which certain genes are regulated or turned "on" or "off" -- is one of the most fundamental processes in the life of any biological cell. Different programs of gene expression -- even when cells have the same DNA -- can lead to different cellular behavior and function. For example, even though a human muscle cell and a human nerve cell have identical DNA, they behave and function very differently. "Gene expression tends to vary from cell to cell," Bai said. "Misregulation may happen in a small fraction of cells, and these cells may cause disease later on. Therefore it is important to study gene regulation at the single-cell level."