The project’s scientists also found a new use for DNA sequences previously dismissed as a nuisance

Next-Generation Discoveries



In this study, scientists focused on telomeres, the repetitive segments of DNA at the ends of chromosomes. Telomeres are widely recognized as playing an important role in chromosomes and human health. But unlike other parts of the human genome, telomeres all have the same six-letter DNA sequence. That means researchers mapping the entire genomes typically dismissed this DNA as “junk” because telomeric DNA could not be assigned to a particular spot in the genome.

Jinghui Zhang, PhD, of Computational Biology, credits postdoctoral fellow Matthew Parker, PhD, with recognizing a simple but powerful solution. Rather than worrying about mapping telomeric DNA, Parker suggested focusing instead on the volume of telomeric DNA, particularly changes between normal and cancer cells. The strategy helped researchers to link mutations in a gene named ATRX to increased telomeric DNA in patients with a high-risk form of neuroblastoma.

“The telomere findings gave us information about the mutation’s impact that otherwise would have been difficult to get,” Parker says.

The latest findings came amid planning for Phase II of the Pediatric Cancer Genome Project. The next stage will build on the lessons and surprises revealed in the course of successfully completing one of the hospital’s most ambitious efforts.

James Downing, MD, St. Jude scientific director, says the next challenges include learning how to transform this powerful technology from a research finding into a clinical tool.

Learn more about the Pediatric Cancer Genome Project

Abridged from Promise, Spring 2013