SciTech Daily April 25, 2021
Previously an international team of researchers (USA – Florida State University, Emory University, University of Georgia, University of Illinois, Sloan Kettering Cancer Center, UK, Japan, Hong Kong) showed that each type of cell had a unique replication timing program and that diseased cells had distinct alterations in the program. In the current study, the team looked at how changes in the replication timing program impact the epigenome. They found that by eliminating a protein called RIF1, that helps to regulate DNA replication, the replication program was severely and sometimes, almost completely gone so that all segments of chromosomes were replicating at different times in different cells. Without RIF1, if cells were prevented from replicating DNA, their epigenomes were fine. However, as soon as the DNA started to replicate, the regulatory molecules that associate with the DNA became incorporated incorrectly and worsened with each round of DNA replication. Eventually, the 3-dimensional folding of the chromosomes was also altered. It has been shown that specific patterns of altered timing that were linked statistically to poor outcomes in pediatric leukemia, and in another study to diseases of premature aging. The results from this study will provide valuable information for human health and disease studies in the future…read more. TECHNICAL ARTICLE