Huge childhood cancer DNA catalogue released

By releasing a huge catalogue of complete DNA data on childhood cancers to the global scientific community, a team at St Jude Children's Research Hospital in Memphis, Tennessee, in the US, hopes to speed up progress in finding causes and new treatments for cancer and other diseases. The catalogue contains whole genome sequences, essentially complete DNA maps, from 260 child cancer patients. There are 520 sequences in all, comprising matched sets of normal and tumor tissue samples. The scientists releasing the data are working on the Washington University Pediatric Cancer Genome Project, which is expected to sequence more than 1,200 genomes by the end of this year. The release, thought to be the largest ever of its kind to the scientific community, was announced as part of a Perspective article published in Nature Genetics on Tuesday. To ensure maximum accuracy of the data, each sample is sequenced 30 times. The information will be valuable not only to researchers in the field of cancer, but also to scientists investigating all kinds of diseases. Researchers at St Jude are looking to pinpoint the differences between the genomes of healthy and cancerous cells to identify the causes of more than half a dozen deadly childhood cancers. Their work has already yielded several important discoveries, which they have written about in leading scientific journals. Some of these discoveries include significant insights into aggressive childhood cancers of the retina, brainstem and blood. For example, while investigating what lies behind the rapid development of the eye tumor retinoblastoma, project researchers identified a new promising anti-cancer agent. On another part of the project, scientists studying a deadly childhood leukemia called ETP-ALL (short for early T-precursor acute lymphoblastic leukemia), discovered some unexpected genome differences that could improve diagnosis and treatment for children with the disease. James Downing is a St Jude scientific director and leader of the project at St Jude. He told the press these findings, and others, would not have been possible without the Pediatric Cancer Genome Project, and: "By sharing the information ... we're hoping that other researchers can use this rich resource for insights into many other types of diseases in children and adults," he said. The Pediatric Cancer Genome Project is different because unlike many genome projects, it is producing whole genome data sets, that show entire DNA sequences, instead of focusing on individual genes. Such data sets give a much richer, complete picture of the DNA changes behind the causes and progression of disease. Richard K Wilson, director of The Genome Institute at Washington University School of Medicine in St Louis, said with this approach they have found some unusual, "cryptic" changes in many patients' cancer cells that they would not have found using other methods. The project has also shown there are some marked differences between childhood and adult cancers, underlining why it is important to develop separate treatments for each. Researchers will be able to access the data online by submitting a request to the European Genome-Phenome Archive.