Genotype specific differences in expression profiles have been evaluated using Gene Chips.
High-throughput screening for the identification of new therapeutic options for metastatic pheochromocytoma and paraganglioma.
Specimen part, Disease
View SamplesAcute myeloid leukemia (AML) is a heterogeneous disease and AML with normal karyotype (AML-NK) is categorized as an intermediate-risk group. Over the past years molecular analyses successfully identified biomarkers that will further allow to dissecting clinically meaningful subgroups in this disease. Thus far, somatic mutations were identified which elucidate the disturbance of cellular growth, proliferation, and differentiation processes in hematopoietic progenitor cells. In AML-NK, acquired gene mutations with prognostic relevance were identified for FLT3, CEBPA, and NPM1. FLT3-ITD mutations were associated with short relapse-free and overall survival, while mutations in CEBPA or NPM1 (without concomitant FLT3-ITD) had a more favorable outcome.
Quantitative comparison of microarray experiments with published leukemia related gene expression signatures.
Sex, Age, Disease, Disease stage
View SamplesAlternative mRNA splicing represents an effective mechanism of regulating gene function and is a key element to increase the coding capacity of the human genome. Today, an increasing number of reports illustrates that aberrant splicing events are common and functionally important for cancer development. However, more comprehensive analyses are warranted to get novel insights into the biology underlying malignancies like e.g. acute myeloid leukemia (AML). Here, we performed a genome-wide screening of splicing events in AML using an exon microarray platform. We analyzed complex karyotype and core binding factor (CBF) AML cases (n=64) in order to evaluate the ability to detect alternative splicing events distinguishing distinct leukemia subgroups. Testing different commercial and open source software tools to compare the respective AML subgroups, we could identify a large number of potentially alternatively spliced transcripts with a certain overlap of the different approaches. Selected candidates were further investigated by PCR and sequence analysis: out of 24 candidate genes studied, we could confirm alternative splice forms in 8 genes of potential pathogenic relevance, such as PRMT1 regulating transcription through histone methylation and participating in DNA damage response, and PTPN6, which encodes for a negative regulator of cell cycle control and apoptosis. In summary, this first large Exon microarray based study demonstrates that transcriptome splicing analysis in AML is feasible but challenging, in particular with regard to the currently available software solutions. Nevertheless, our results show that alternatively spliced candidate genes can be detected, and we provide a guide how to approach such analyses.
A robust estimation of exon expression to identify alternative spliced genes applied to human tissues and cancer samples.
Specimen part, Disease, Disease stage
View SamplesLong-term treatment of Kasumi-1 cells at clinically attained doses of dasatinib led to decreased drug-sensitivity by means of IC50 values (relative to treatment-naive cells). Changes were paralled by profound alterations in c-KIT expression and cell signaling signatures. Upon brief discontinuation of dasatinib treatment, these alterations reversed and drug sensitivity was restored.
Transitory dasatinib-resistant states in KIT(mut) t(8;21) acute myeloid leukemia cells correlate with altered KIT expression.
Cell line
View SamplesOncogenic tyrosine kinases, such as BCR-ABL, TEL-ABL, TEL-PDGF-beta-R and FLT3-ITD, play a major role in the development of hematopoietic malignancy. They activate many of the same signal transduction pathways.
Id1 is a common downstream target of oncogenic tyrosine kinases in leukemic cells.
No sample metadata fields
View SamplesThalidomide Exerts Distinct Molecular Antileukemic Effects and Combined Thalidomide/Fludarabine Therapy is Clinically Effective in High-Risk Chronic Lymphocytic Leukemia
Thalidomide exerts distinct molecular antileukemic effects and combined thalidomide/fludarabine therapy is clinically effective in high-risk chronic lymphocytic leukemia.
No sample metadata fields
View SamplesCore binding factor (CBF) leukemias, characterized by translocations t(8;21) or inv(16)/t(16;16) targeting the core binding factor, constitute acute myeloid leukemia (AML) subgroups with favorable prognosis. However, about 40% of patients relapse, and the current classification system does not fully reflect this clinical heterogeneity. Previously, gene expression profiling (GEP) revealed two distinct CBF leukemia subgroups displaying significant outcome differences and identified apoptotic signaling, MAPKinase signaling and chemotherapy-resistance mechanisms among the most significant differentially regulated pathways. We now tested different inhibitors of the respective pathways in a cell line model (six cell lines reflecting the CBF subgroup specific gene expression alterations), and found apoptotic signaling to be differentiating between the CBF subgroup models. In accordance, primary samples from newly diagnosed CBF AML patients (n=23) also showed differential sensitivity to in vitro treatment with a Smac mimetic such as BV6, an antagonist of inhibitor of apoptosis (IAP) proteins , and ABT-737, a BCL2 inhibitor. Furthermore, GEP revealed the BV6 resistant cases to resemble the previously identified unfavorable CBF subgroup. Thus, our current findings show deregulated IAP expression and apoptotic signaling to differentiate clinically relevant CBF subgroups, which were independent of known molecular markers, thereby providing a starting point for novel therapeutic approaches.
Deregulated apoptosis signaling in core-binding factor leukemia differentiates clinically relevant, molecular marker-independent subgroups.
Sex, Age
View SamplesThe aim of the study was to investigate the role of TGIF1 in MLL-AF9 transformed cells
TGIF1 is a negative regulator of MLL-rearranged acute myeloid leukemia.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MYC stimulates EZH2 expression by repression of its negative regulator miR-26a.
Specimen part
View SamplesCalorie restriction (CR) is a dietary intervention that extends lifespan and healthspan in a variety of organisms. CR improves mitochondrial energy production, fuel oxidation and reactive oxygen species scavenging in skeletal muscle and other tissues, and these processes are thought to be critical to the benefits of CR. PGC-1a is a transcriptional coactivator that regulates mitochondrial function and is induced by CR. Consequently, many of the mitochondrial and metabolic benefits of CR are attributed to increased PGC-1a activity. To test this model for the first time, we examined the metabolic and mitochondrial response to CR in mice lacking skeletal muscle PGC-1a (MKO). Surprisingly, MKO mice demonstrated a normal improvement in glucose homeostasis in response to CR, indicating that skeletal muscle PGC-1a is dispensable for the whole-body benefits of CR. In contrast, gene expression profiling and electron microscopy demonstrated that PGC-1a is required for the full CR-induced increases in mitochondrial gene expression and mitochondrial density in skeletal muscle. These results demonstrate that PGC-1a is a major regulator of the mitochondrial response to CR in skeletal muscle, but surprisingly show that neither PGC-1a nor mitochondrial biogenesis in skeletal muscle are required for the metabolic benefits of CR.
Skeletal muscle transcriptional coactivator PGC-1α mediates mitochondrial, but not metabolic, changes during calorie restriction.
Specimen part
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