To study differentially expressed genes in neuro-ectodermal cell lines
Downregulation of Axl in non-MYCN amplified neuroblastoma cell lines reduces migration.
Sex, Specimen part
View SamplesHigh anaplastic lymphoma kinase (ALK) protein levels may be correlated with an unfavorable prognosis in neuroblastoma (NBL) patients, regardless of ALK mutation status. We therefore examined the correlation between levels of ALK, phosphorylated ALK (pALK) and downstream signaling proteins and response to ALK inhibition in a large panel of both ALK mutated (MUT) and wild type (WT) NBL cell lines. Six of the nineteen NBL cell lines had a point mutation and four an amplification of the ALK gene. ALK amplified cell lines showed similar ALK levels and ALK inhibitor sensitivity as WT cell lines and were therefore co-analyzed. The ALK mRNA (p=0.043), ALK 220 kDa (p=0.009) and ALK 140 kDa (p=0.025) protein levels were higher in ALK mutant (n=6) than WT cell lines (n=13). ALK mRNA and protein levels significantly correlated with ERK1 and ERK2 protein levels, and also with PHOX2B mRNA levels, a neural differentiation marker which is mutated in NBL. Response to ALK inhibitor TAE684 was also significantly correlated with ALK levels. ALK mutant cell lines (n=4) demonstrated a higher sensitivity towards ALK inhibitor TAE684 (14.9 fold more sensitive, p=0.004) than eight WT cell lines. These results underline the importance of ALK mutations but also ALK levels for response to ALK inhibitors in NBL cell lines. Furthermore, the strong correlation of PHOX2B and ALK suggests that neural differentiation stage may be correlated with ALK levels in neuroblastoma. These data will enhance understanding of ALK inhibitor response in future patient trials.
Anaplastic lymphoma kinase (ALK) inhibitor response in neuroblastoma is highly correlated with ALK mutation status, ALK mRNA and protein levels.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Epigenetic drug combination induces genome-wide demethylation and altered gene expression in neuro-ectodermal tumor-derived cell lines.
Sex, Specimen part, Disease, Cell line, Treatment
View SamplesAbstract: Epigenetic alterations are a fundamental aspect of cancer cells, and epigenetic drugs are currently used in clinical practice for hematological malignancies. Pediatric neuro-ectodermal tumors originate from neural crest cells and show epigenetic defects of apoptotic pathways, which makes the introduction of epigenetic drugs in this patient category logical. However, the young age of these patients is accompanied by ongoing developmental processes which are regulated epigenetic mechanisms, and prompted us to study molecular effects of nanomolar dosage epigenetic drugs in neuro-ectodermal tumor cell lines. Combination treatment of 5-aza-2`-deoxicytidine (DAC) and Trichostatin A (TSA) at nanomolar dosages resulted in wide-spread demethylating effects in 17 NBL and 5 PNET cell lines in vitro. This widespread demethylation had large effects on gene-expression profiles. In NBL cell lines, almost every cellular pathway (193/200) investigated demonstrated altered expression upon treatment, and resulted in upregulation of known epigenetically regulated genes such as X-chromosomal, tissue-specific, and a few imprinted genes. Integration analysis of CpG island methylation array data and whole genome gene expression data identified 30 genes potentially upregulated by gene promoter demethylation. Homeobox genes frequently showed demethylation in both short term (72 hours) and long term cultures (3 months) of NBL lines. Continuous treatment with epigenetic drugs resulted in low rates of proliferation. The low rate of proliferation that might explain limited consecutive demethylation upon prolonged exposure. In conclusion, genome-wide methylation and gene expression changes are induced DAC and TSA treatment at nanomolar dosages. These effects affected more than 97% of cellular pathways investigated. Further studies towards the effects of epigenetic drug combinations are advised before being applied in clinical trials for pediatric patients.
Epigenetic drug combination induces genome-wide demethylation and altered gene expression in neuro-ectodermal tumor-derived cell lines.
Sex, Specimen part, Cell line
View SamplesGenomic aberrations of Cyclin D1 (CCND1) and CDK4 in neuroblastoma indicate that dysregulation of the G1 entry checkpoint is an important cell cycle aberration in this pediatric tumor. Here we report that analysis of Affymetrix expression data of primary neuroblastic tumors shows an extensive over-expression of Cyclin D1 and CDK4 which correlates with histological subgroups and prognosis respectively. Immunohistochemical analysis demonstrated an over-expression of Cyclin D1 in neuroblasts and a low Cyclin D1 expression in all cell types in ganglioneuroma. This suggests an involvement of G1 regulating genes in neuronal differentiation processes which we further evaluated using RNA interference against Cyclin D1 and its kinase partner CDK4 in several neuroblastoma cell lines. This resulted in pRb pathway inhibition as shown by an almost complete disappearance of CDK4 specific pRb phosphorylation; reduction of E2F transcriptional activity and a decrease of Cyclin A protein levels. The Cyclin D1 and CDK4 knock-down resulted in a significant reduction in cell proliferation, a G1 specific cell cycle arrest and moreover an extensive neuronal differentiation. Affymetrix microarray profiling of siRNA treated cells revealed a shift in expression profile towards a neuronal phenotype. Several new potential downstream players are identified. We conclude that neuroblastoma functionally depend on over-expression of G1 regulating genes to maintain their undifferentiated phenotype.
Cyclin D1 and CDK4 activity contribute to the undifferentiated phenotype in neuroblastoma.
No sample metadata fields
View SamplesThe pathogenesis of classical Hodgkin lymphoma (cHL), the most common lymphoma in the young, is still enigmatic, largely because its Hodgkin and Reed-Sternberg (HRS) tumor cells are rare in the involved lymph node and therefore difficult to analyze. Here, by overcoming this technical challenge and performing for the first time a genome-wide transcriptional analysis of microdissected HRS cells in comparison to other B-cell lymphomas, cHL lines and normal B-cell subsets, we show that they differ extensively from the usually studied cHL cell lines, that the lost B-cell identity of cHLs is not linked to the acquisition of a plasma cell-like gene expression program, and that Epstein-Barr virus infection of HRS cells has a minor transcriptional influence on the established cHL clone. Moreover, although cHL appears a distinct lymphoma entity overall, HRS cells of its histological subtypes diverged in their similarity to other related lymphomas. Unexpectedly, we identified two molecular subgroups of cHL associated to differential strengths of the transcription factor activity of the NOTCH1, MYC and IRF4 proto-oncogenes. Finally, HRS cells display deregulated expression of several genes potentially highly relevant to lymphoma pathogenesis, including silencing of the apoptosis-inducer BIK and of INPP5D, an inhibitor of the PI3K-driven oncogenic pathway.
Analyzing primary Hodgkin and Reed-Sternberg cells to capture the molecular and cellular pathogenesis of classical Hodgkin lymphoma.
Specimen part, Cell line
View SamplesWhole genome sequencing detected structural rearrangements of TERT in 17/75 high stage neuroblastoma with 5 cases resulting from chromothripsis. Rearrangements were associated with increased TERT expression and targeted immediate up- and down-stream regions of TERT, placing in 7 cases a super-enhancer close to the breakpoints. TERT rearrangements (23%), ATRX deletions (11%) and MYCN amplifications (37%) identify three almost non-overlapping groups of high stage neuroblastoma, each associated with very poor prognosis
TERT rearrangements are frequent in neuroblastoma and identify aggressive tumors.
Specimen part
View SamplesThe pathogenesis of nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) and its relationship to other lymphomas are largely unknown. This is partly due to the technical challenge of analyzing its rare neoplastic L&H cells, which are dispersed in an abundant non-neoplastic cellular microenvironment. We performed a genome-wide expression study of microdissected lymphocytic and histiocytic (L&H) lymphoma cells in comparison to normal and other malignant B cells, which indicates a relationship of L&H cells to and/or origin from germinal center B cells at transition to memory B cells. L&H cells show a surprisingly high similarity to the tumor cells of T cell-rich B cell lymphoma and classical Hodgkin lymphoma, a partial loss of their B cell phenotype and deregulation of many apoptosis-regulators and putative oncogenes. Importantly, L&H cells are characterized by constitutive NF-B activity and aberrant ERK signaling. Thus, these findings shed new light on the nature of L&H cells, revealed several novel pathogenetic mechanisms in NLPHL, and may help in differential diagnosis and lead to novel therapeutic strategies.
Origin and pathogenesis of nodular lymphocyte-predominant Hodgkin lymphoma as revealed by global gene expression analysis.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
TGFβ signaling directs serrated adenomas to the mesenchymal colorectal cancer subtype.
Specimen part, Treatment
View SamplesThe aim of this study was to determine the effects of TGF at the premalignant stage of CRC development.
TGFβ signaling directs serrated adenomas to the mesenchymal colorectal cancer subtype.
Specimen part, Treatment
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