Identifying Synthetic Lethality with MYCN Amplification in Neuroblastoma

Neuroblastoma is a cancer that derives from neural crest cells and is the most common extracranial tumor in children and infants. The most common marker of poor prognosis and rapid tumor development in neuroblastoma is MYCN amplification.  At the moment, no drug therapy targets neuroblastoma cells with MYCN amplification because it is difficult to target transcriptional factors directly. Our approach to target neuroblastoma cells with MYCN amplification is to identify genes that have synthetic lethality with MYCN amplification. Two genes are synthetically lethal if a mutation in either gene allows the cell to survive, but with a mutation in both genes inducing cell death.  A whole genome short hairpin RNA (shRNA) screen has revealed candidate genes for synthetically lethal interactions with MYCN amplification. The effects of gene silencing in MYCN amplified neuroblastoma cells were analyzed through proliferation, apoptosis and competition assays. We have found that when shRNA is used to silence one candidate gene, SHEP neuroblastoma cells over-expressing MYCN, experience a decline in proliferation and are less viable than control SHEP cells in which MYCN over-expression is switched off. Future directions of this study involve expanding the conditions to include hypoxia, validating our model in different neuroblastoma cell lines and studying these synthetic lethal interactions in vivo.