MAGIC team of scientists find new strategies for treating childhood brain cancer

01 August 2012

David Shih, one of the lead authors on the study and a graduate student working with Dr Michael TaylorAugust 2012 – An international team of scientists is one step closer to figuring out what causes some children to get medulloblastoma, the most common form of malignant brain cancer in very young children.

Every year in Canada, between 30 and 40 babies and young children are diagnosed with medulloblastoma. While more than two-thirds survive, many children are left with permanent neurological, intellectual and physical impairments – the result of harsh radiation treatments that damage their developing brains.

The international team of experts – called MAGIC, short for Medulloblastoma Advanced Genomics International Consortium – says that by identifying what goes wrong in brain cells, better and more targeted treatments for this cancer can be developed. The study, funded in part by the Canadian Cancer Society, is the largest ever done on medulloblastoma.

An earlier study, led by Dr Michael Taylor at SickKids (The Hospital for Sick Children) and funded by the Society, classified medulloblastomas into 4 main subgroups based on clinical and genetic differences. Dr Taylor is also the lead investigator for the MAGIC team. For the current study, researchers want to gain a deeper understanding of what differentiates the subgroups in the hope of developing effective therapies targeted to a specific subset of patients – some children may be able to avoid brain irradiation and be spared its side effects.

For the study, researchers collected over 1200 medulloblastoma samples from 45 hospitals around the world (only 100 samples were used in the previous study) and analyzed the samples using a technique that identifies defects in chromosomes. Unlike other cancers, there have been few genetic mutations identified in medulloblastoma. Scientists used a large-scale approach to identify changes on the chromosomes of each tumour subgroup.

For each of the subgroups, unique chromosome abnormalities were identified. Surprisingly, one of the medulloblastoma subgroups had an increased number of copies of a gene involved in Parkinson’s disease. This gene – SNCAIP – is often mutated or non-functional in Parkinson’s. This is the first time a Parkinson’s-related gene has been implicated in medulloblastoma. The role of SNCAIP is still unclear – more studies are needed to understand why there is a decrease in its function in Parkinson’s disease but an increase in its function in medulloblastoma.

“This is an incredibly large study that has helped identify a number of genetic targets that can now be followed up in the clinic,” says David Shih, one of the primary investigators on the study and a graduate student working under Dr Taylor. “What’s exciting is that drugs are already available for some of the targets we found and therefore we’ll be able to test our findings much sooner rather than later,” says Shih.

The study was published online July 25, 2012 in the scientific journal Nature.