Repli-seq data for "Replication timing alterations are associated with mutation acquisition during tumour evolution in breast and lung cancer"

The essential process of DNA replication timing during each cell cycle is highly regulated ensuring the correct duplication of the genome. The extent and importance of alterations in this process during malignant transformation has not been extensively explored. Here, we evaluate the impact of altered replication timing (ART) on cancer evolution by analysing replication-timing sequencing of cancer and normal cell lines and 952 whole-genome sequenced lung and breast tumours. We find 6%-18% of the cancer genome displays ART. Genomic regions with a change from early to late replication exhibit an increased mutation rate and distinct mutational signatures, while regions changing from late to early contain genes with increased expression and present a preponderance of APOBEC3-mediated mutation clusters and associated driver mutations. We demonstrate that ART is a relatively early event during cancer evolution and that ART may have a stronger correlation with mutation acquisition than alterations in chromatin structure.EGA study EGAS00001007773