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:Methylome of tumor cell-free DNA (cfDNA) has emerged as a powerful non-invasive technique for cancer subtyping and prognosis. However, its application is frequently hampered by the quality and total cfDNA yield. Here we demonstrate the feasibility of very low-input cfDNA for whole-methylome and copy-number profiling studies using enzymatic conversion of unmethylated cysteines (EMSEQ) to better preserve DNA integrity. We demonstrate that cfDNA methylation of our cohort was comparable with in situ cohorts and built a model that accurately predict MYCN amplification or 11q deletion in validation cohorts. RASSF1A methylation precedes this divergent methylome signature, supporting common and different epigenetic origins. After stratification by 11q, eight CpG methylations show additional prognostic value and two reveal known preclinical targets (CSF1R, CCR7). Methylation in CSF1R and CCR7 associated with differential expression levels and poorer prognosis. Noteworthy, haploinsufficiency of genes located on 11q that repair DNA double-strand breaks display reduced expression by a mechanism independent of promoter methylation. Conclusions: RASSF1A is an early hypermethylation defect that may predispose to later genetic and epigenetic alterations specific to MYCN-amplified or 11q-deleted high-risk neuroblastomas. CSF1R and CCR7 hypermethylation are a hallmark of high-risk 11q-deleted neuroblastomas that could be exploited therapeutically with immunomodulators to override immunosupression and relapse. Our novel findings provide support for use of liquid biopsy as an optimal strategy to assess methylomes of neuroblastoma patients for a precision medicine approach.
