August Winner of the Étudiants-chercheurs étoiles Award

Xiaoyang Liu, PhD student in human genetics, is the award winner of the  Fonds Santé, one of the three Fonds awards of the Fonds de recherche du Québec. Her winning article “Driver mutations in histone H3.3 and chromatin remodelling in peadiatric glioblastoma” is published in Nature, Vol.482, January 29, 2012, Pages 226-231

In this article, she explains that, “[they] sequenced the exomes of 48 paediatric gioblastoma multiforme (GBM) samples. Somatic mutations in the H3.3-ATRX-DAXX chromatin remodelling pathway were identified in 44% of tumours, and associated with alternative lengthening of telomeres. Three recurrent mutations in H3F3A encoding histone variant H3.3 were observed in 31% of tumours. ATRX and DAXX required for H3.3 incorporation at pericentric heterochromatin and telomeres were identified in 31% of samples. H3F3A mutations are specific to GBM and highly prevalent in children and young adults.”

This is a major genetic breakthrough that could change the way paediatric cancers are treated in the future. It helps explain the ineffectiveness of conventional treatments against cancer in children. Xiaoyang Liu showed that GBM in children is due to different molecular mechanisms than those in adults, and should not be treated in the same way. For the first time in humans the team has identified a mutation in one of the most important genes that regulates and protects our genetic information. This discovery is important in the developement of personalized medicine: treatment should be given to patients based on their genetic background. For patients with the mutations we identified, targeting this pathway should be considered, in order to get better treatment efficacy. The diagnosis of gliobastoma in a child or adolescent is currently a death sentence and about 200 children in Canada die every year of this cancer.that the cellular inhibitors of apoptosis proteins (cIAPs) are fundamental to the immune response triggered when danger signals are sensed by the cytosolic complex known as inflammasome. Molecular mechanism studies reveal the major role of the cIAPs in the inflammasome-dependent activation of caspase-1, a key effector protein in inflammation and cell death, which lead to pathogen elimination and cell repair.