Project description:SNP arrays were combined with next generation sequencing (NGS) to precisely define the deleted region in 17 primary 11q-loss neuroblastomas and identify allelic variants in genes relevant for neuroblastoma aetiology. We assessed PARP inhibitor olaparib in combination with other chemotherapy medications using both in vitro and in vivo models.
Project description:SNP arrays were combined with next generation sequencing (NGS) to precisely define the deleted region in 17 primary 11q-loss neuroblastomas and identify allelic variants in genes relevant for neuroblastoma aetiology. We assessed PARP inhibitor olaparib in combination with other chemotherapy medications using both in vitro and in vivo models.
Project description:Neuroblastomas are characterized by recurrent segmental and/or numerical chromosomal abberations such as MYCN-amplification or 11q-deletion. To further elucidate recurrent chromosomal alterations, 16 neuroblastoma cell lines were investigated.
Project description:High-risk 11q deleted neuroblastomas (NBs) typically display an undifferentiated/poorly differentiated morphology. NB is thought to develop from Schwann cell precursors (SCPs) and un-differentiated neural crest derived cells (NCC). It is therefore vital to understand the mechanisms involved in the block of differentiation. We showed that an important and novel role for oncogenic ALK-ERK1/2-SP1 signaling may be the maintenance of an undifferentiated state of transformed NC-derived progenitors that is achieved by repression of DLG2, a tumor suppressor in NB. DLG2 is expressed in the ‘bridge signature’ that represents the transcriptional transition state when neural crest cells or Schwann Cell Precursors (SCP) become chromaffin cells of the adrenal gland. The importance of SP1 and DLG2 in this process is highlighted by our findings that restoring DLG2 expression spontaneously drives NB differentiation. Further, genetic analysis of high-risk 11q deletion NB patient identified genetic lesions in the DLG2 gene, Our data also suggest that further exploration of other ‘bridge genes’ may help to better understand the mechanisms underlying the differentiation of NC-derived progenitors and their contribution to NB.
Project description:Detailed analysis of 11q aberrations consisted of duplication, terminal deletion and inversion performed by SNP/aCGH on 11 patients with BLL,11q; BL and HGBL,NOS diagnosis.
Project description:This SuperSeries is composed of the following subset Series: GSE25170: MYC drives resistance to PI3K/mTOR targeted inhibition (Sty SNP array) GSE25172: MYC drives resistance to PI3K/mTOR targeted inhibition (gene expression) Refer to individual Series
Project description:Gene expression analysis was performed on 30 Neuroblastomas to identify genes whose transcription is significantly altered by recurrent chromosomal alterations. Genomic copy number losses and gains had been delineated in the tumours using FISH and SNP arrays. We have identified genes significantly altered by 7 recurrent alterations: 1p, 3p, 4p, 10q and 11q loss, 2p and 17q gain, and genes co-amplified and over-expressed as a result of MYCN amplification. Subsequently, correlation of microarray data with survival and expression within rodent neuroblastomas were used to identify genes likely to be involved in the disease progression, and identified a significant excess of differentially expressed genes which correlated with survival within the minimally altered regions on 17q and 4p; Identifying genes whose expression is consistently altered by chromosomal gains or losses is an important step in defining genes of biological relevance in a wide variety of tumour types. However, additional criteria are needed to discriminate further among the large number of candidate genes identified. This is particularly true for neuroblastoma, where multiple genomic copy number changes of proven prognostic value exist. We have used Affymetrix microarrays and a combination of fluorescent in-situ hybridisation and single nucleotide polymorphism (SNP) microarrays to establish expression profiles and delineate copy number alterations in 30 primary neuroblastomas. Correlation of microarray data with patient survival and analysis of expression within rodent neuroblastoma cell lines were then used to further define genes likely to be involved in the disease process. Using this approach we identify >1000 genes within 8 recurrent genomic alterations (loss of 1p, 3p, 4p, 10q and 11q, 2p gain, 17q gain, and the MYCN amplicon) whose expression is consistently altered by copy number change. Of these, 84 correlate with patient survival, with the minimal regions of 17q gain and 4p loss being significantly enriched for such genes. Orthologues of all but one of these genes on 17q are overexpressed in rodent neuroblastoma cell lines. A significant excess of SNPs whose copy number correlates with survival is also observed on proximal 4p in stage 4 tumours, and we find that deletion of 4p is associated with improved outcome in an extended cohort of tumours. These results define the major impact of genomic copy number alterations upon transcription within neuroblastoma, and highlight genes on distal 17q and proximal 4p for downstream analyses. They also suggest that integration of discriminators such as survival and comparative gene expression with microarray data may be useful in the identification of critical genes within regions of loss or gain in many human cancers. Experiment Overall Design: Chromosomal gains and losses were delineated in Stage 4 neuroblastomas to facilitate, in combination with expression array data, the identification of genes within regions of gain and loss whose expression is significantly altered by copy number change.