Project description:This SuperSeries is composed of the following subset Series: GSE17827: Integrated bioinformatic and wet-lab approach to identify potential oncogenic networks in neuroblastoma: MEIS1 GSE18271: Analysis of TALE homeobox genes in neuroblastic tumors: ganglioneuroblastoma and ganglioneuroma Refer to individual Series
Project description:A large proportion of patients suffering from the malignant pediatric tumor neuroblastoma die of progressive disease despite intensive therapy. Neuroblastomas belong to the group of neuroblastic tumors, together with the more benign, differentiated ganglioneuroblastomas and ganglioneuromas. Little is known of the genes driving the differentiation processes in these tumor types. A search for the transcription factors differentially expressed between ganglioneuromas, ganglioneuroblastomas, and neuroblastomas in a series of 110 neuroblastic tumors (NB110) identified a large number of HOX- and TALE (Three Amino acid Loop Extension)-class homeobox transcription factor genes. The MEIS1-3, PBX1 and -3, and PKNOX1 TALE genes showed highest expression in neuroblastomas and lowest in ganglioneuromas and ganglioneuroblastomas. The PKNOX2 and TGIF1-2 genes showed the opposite expression pattern. This suggests an involvement of TALE genes in neuroblastoma differentiation. Expression of MEIS1, a known oncogene in haematopoietic tumors, was high in all neuroblastomas, and strongly correlated with undifferentiated histology. Consequently, we generated IMR-32 neuroblastoma cells capable of inducible shRNA-mediated MEIS1 knockdown. We observed differentiation, growth arrest and induction of apoptosis upon MEIS1 down-regulation. Affymetrix profiling of time-course experiments using these cells allowed the identification of MEIS1 target genes. Analysis of the target genes in the NB110 series showed that 323 of these were also significantly correlated to MEIS1 expression and to tumor differentiation in neuroblastic tumors. Genes involved in the cell cycle and in developmental pathways were over-represented in this gene set. We conclude that MEIS1 governs several of the signal transduction routes important for neuroblastoma survival and differentiation. 12 ganglioneuroma (gn) and 10 ganglioneuroblastoma (gnb) were analyzed.
Project description:A large proportion of patients suffering from the malignant pediatric tumor neuroblastoma die of progressive disease despite intensive therapy. Neuroblastomas belong to the group of neuroblastic tumors, together with the more benign, differentiated ganglioneuroblastomas and ganglioneuromas. Little is known of the genes driving the differentiation processes in these tumor types. A search for the transcription factors differentially expressed between ganglioneuromas, ganglioneuroblastomas, and neuroblastomas in a series of 110 neuroblastic tumors (NB110) identified a large number of HOX- and TALE (Three Amino acid Loop Extension)-class homeobox transcription factor genes. The MEIS1-3, PBX1 and -3, and PKNOX1 TALE genes showed highest expression in neuroblastomas and lowest in ganglioneuromas and ganglioneuroblastomas. The PKNOX2 and TGIF1-2 genes showed the opposite expression pattern. This suggests an involvement of TALE genes in neuroblastoma differentiation. Expression of MEIS1, a known oncogene in haematopoietic tumors, was high in all neuroblastomas, and strongly correlated with undifferentiated histology. Consequently, we generated IMR-32 neuroblastoma cells capable of inducible shRNA-mediated MEIS1 knockdown. We observed differentiation, growth arrest and induction of apoptosis upon MEIS1 down-regulation. Affymetrix profiling of time-course experiments using these cells allowed the identification of MEIS1 target genes. Analysis of the target genes in the NB110 series showed that 323 of these were also significantly correlated to MEIS1 expression and to tumor differentiation in neuroblastic tumors. Genes involved in the cell cycle and in developmental pathways were over-represented in this gene set. We conclude that MEIS1 governs several of the signal transduction routes important for neuroblastoma survival and differentiation.
Project description:Detection of DNA hypermethylation across all UCSC annotated CpG islands and refseq promoter sequences in neuroblatoma cell lines and neuroblastic tumors
Project description:Tumor tissue heterogeneity is a well known feature of several solid tumors. Neuroblastic Tumors (NTs) is a group of paediatric cancers with a great tissue heterogeneity. Most of NTs are composed of undifferentiated, poorly differentiated or differentiating neuroblastic (Nb) cells with very few or absent Schwannian stromal (SS) cells: these tumors are grouped as Neuroblastoma (Schwannian stroma-poor). The remaining NTs are composed of abundant SS cells and classified as Ganglioneuroblastoma (Schwannian stroma-rich) intermixed or nodular and Ganglioneuroma. The importance to understand Nb and SS gene signatures in NTs, is to clarify the complex network mechanism of tumor growth and progression. In order to identify the Nb and SS cells gene signatures, we analyzed the gene expression profiling of 19 cases of neuroblastic tumors: 10 stroma poor (NTs-SP) and 9 stroma rich (NTs-SR), by high density oligonucleotide microarrays. Moreover, the analysis was performed in parallel on both whole and laser microdissected tumor samples: from 4 of 19 cases, was isolated different areas all composed of pure cellular populations. We performed genome wide expression analysis by using Affymetrix technology and we used two different approaches for data analysis: SAM (Significance Analysis of Microarrays) and a method based on Game Theory (GT), to identify genes differently expressed in SS and Nb cells. Differently from the SAM method, the analysis based on GT (Moretti et al. (2006)) gives the advantage of selecting relevant genes not only according to the expression profile of each single gene, but considering also gene interaction. Keywords: Gene signature of Neuroblastic and Schwannian stromal cells.
Project description:This SuperSeries is composed of the following subset Series: GSE18139: Array-based gene expression in neuroblastic tumors GSE18143: aCGH of neuroblastic tumors Refer to individual Series