In this week's Nature, a team led by the University of Queensland's Sean Grimmond presents data from an analysis of pancreatic cancer genomes, uncovering key events driving the development of the disease and pointing to potential biomarkers that may be used to patient responses to treatment. The researchers performed deep whole-genome sequencing of 100 pancreatic cancers and discovered disruptions to known and new genes that promote disease progression. They used this information to classify tumors into four subtypes with potential clinical relevance and showed how a combination of they found could indicate respond to platinum-based drugs in a small group of patients. GenomeWeb has more on this study here.
Also in Nature, a pair of scientists from Pompeu Fabra University in Spain reports the results of an examination of hundreds of cancer genomes, which showed that differential DNA repair — and not differential mutation supply — underlies variation in the mutation rates across the human genome. By analyzing roughly 17 million single-nucleotide variants from the genomes of 652 tumors, the researchers found that regional autosomal mutation rates at megabase resolution are largely stable across cancer types, with differences related to changes in replication timing and gene expression. However, mutations arising after the inactivation of mismatch repair are no longer enriched in early replicating euchromatin relative to late replicating heterochromatin.