Gene expression analysis identified a specific signature of differentially expressed genes discriminating good and poor responders in JMML patients.
Gene expression-based classification as an independent predictor of clinical outcome in juvenile myelomonocytic leukemia.
Specimen part, Disease
View SamplesGenetic studies have shown that human T-ALLs can be divided into subgroups that are characterized by unique gene expression signatures and relate to stages of T-cell differentiation at which the leukemic cells arrest. Each molecular subgroup has characteristic genetic abnormalities that cause aberrant activation of specific T-ALL transcription factor oncogenes, including LYL1/MEF2C, HOXA, TLX1, TLX3 and TAL1/LMO2. Notably, the recently described Early T-cell Precursor ALL (ETP-ALL) patients have leukemic cells that show an early block in T-cell differentiation and significantly overlap with LYL1-positive T-ALL and MEF2C-dysregulated immature T-ALL. We studied the gene expression profiles of 64 primary T-ALL samples and found a high BCL-2 expression in immature T-ALL patients compared to patients belonging to other subgroups.
ABT-199 mediated inhibition of BCL-2 as a novel therapeutic strategy in T-cell acute lymphoblastic leukemia.
Specimen part
View SamplesJuvenile myelomonocytic leukemia (JMML) is a very rare and aggressive stem cell disease that mainly occurs in young children. RAS activation constitutes the core component of oncogenic signaling. In addition, the leukemic blasts of a quarter of JMML patients present with monosomy 7 (-7), whereas more than half of the patients show enhanced age-adjusted fetal hemoglobin (HbF) levels. Hematopoietic stem cell transplantation is the current standard of care. This results in an event-free survival of 50 - 60%, indicating that novel molecular driven therapeutic options are urgently needed. Using gene expression profiling in an extensive series of 82 patient samples, we aimed at understanding the molecular biology behind JMML and identified a previously unrecognized molecular subgroup characterized by high LIN28B expression.
LIN28B overexpression defines a novel fetal-like subgroup of juvenile myelomonocytic leukemia.
Disease
View SamplesPurpose: Severe late normal tissue damage limits radiotherapy treatment regimens. This study aims to validate -H2AX foci decay ratios and induced expression levels of DNA double strand break (DSB) repair genes, found in a retrospective study, as possible predictors for late radiation toxicity. Methods and Materials: Prospectively, decay ratios (initial/residual -H2AX foci numbers) and genome-wide expression profiles were examined in ex vivo irradiated lymphocytes of 198 prostate cancer patients. All patients were followed 2 years after radiotherapy, clinical characteristics were assembled and toxicity was recorded using the Common Terminology Criteria (CTCAE) v4.0. Results: No clinical factors were correlated with late radiation toxicity. Analysis of -H2AX foci uncovered a negative correlation between the foci decay ratio and toxicity grade. Significantly smaller decay ratios were found in grade3 compared to grade 0 patients (p=0.02), indicating less efficient DNA-DSB repair in radio-sensitive patients. Moreover, utilizing a foci decay ratio threshold determined in our previous retrospective study correctly classified 23 of the 28 grade3 patients (sensitivity, 82%) and 9 of the 14 grade 0 patients (specificity, 64%). Grade of toxicity also correlated with a reduced induction of the homologous recombination (HR) repair gene-set. The difference in average fold induction of the HR gene-set was most pronounced between grade 0 and grade3 patients (p=0.008). Conclusions: Reduced responsiveness of HR repair genes to irradiation and inefficient DSB repair correlate with an increased risk of late radiation toxicity. Using a decay ratio classifier, we could correctly classify 82% of the patients with grade3 toxicity. Additional studies are required to further optimize and validate the foci decay assay and to assess its predictive value for late radiation toxicity in patients prostate cancer
Prostate Cancer Patients with Late Radiation Toxicity Exhibit Reduced Expression of Genes Involved in DNA Double-Strand Break Repair and Homologous Recombination.
Specimen part, Subject
View SamplesProtective interactions with bystander cells in micro-environmental niches such as lymph nodes (LNs) contribute to survival and therapy resistance of chronic lymphocytic leukemia (CLL) cells. This is caused by a shift in expression of BCL-2 family members. Pro-survival proteins BCL-XL, BFL-1, and MCL-1 are upregulated by LN-residing T cells through CD40L interaction, presumably via NF-B signaling. Macrophages also reside in the LN, and are assumed to provide important supportive functions for CLL cells. However, if and how macrophages are able to induce survival is incompletely known. We first established that macrophages induced survival due to an exclusive upregulation of MCL-1. Next, we investigated the mechanism underlying MCL-1 induction by macrophages in comparison with CD40L. Genome-wide expression profiling of in vitro macrophage- and CD40L-stimulated CLL cells indicated activation of the PI3K-AKT-mTOR pathway, which was confirmed in ex vivo CLL LN material. Inhibition of PI3K-AKT-mTOR signaling abrogated MCL-1 upregulation and survival by macrophages as well asCD40 stimulation. MCL-1 can be regulated at multiple levels, and we established that AKT leads to increased MCL-1 translation, but does not affect MCL-1 transcription or protein stabilization. Furthermore, among macrophage-secreted factors that could activate AKT, we found that induction of MCL-1 and survival critically depended on C-C Motif Chemokine Receptor-1 (CCR1). In conclusion, this study indicates that two distinct micro-environmental factors, CD40L and macrophages, signal via CCR1 to induce AKT activation resulting in translational stabilization of MCL-1, and hence can contribute to CLL cell survival.
Macrophages confer survival signals via CCR1-dependent translational MCL-1 induction in chronic lymphocytic leukemia.
Specimen part, Disease stage
View SamplesThe LIM-only protein FHL2 is expressed in SMCs and inhibits SMC-rich lesion formation. However, the underlying mechanism behind FHL2's action in SMCs has been only partially resolved. To further elucidate the role of FHL2 in SMCs we compared the transcriptome of cultured SMCs derived from wild-type (WT) and FHL2-knockout (KO) mice.
LIM-only protein FHL2 is a positive regulator of liver X receptors in smooth muscle cells involved in lipid homeostasis.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genome-wide identification of expression quantitative trait loci (eQTLs) in human heart.
Sex, Age, Specimen part
View SamplesIn recent years genome-wide association studies (GWAS) have uncovered numerous chromosomal loci associated with various electrocardiographic traits and cardiac arrhythmia predisposition. A considerable fraction of these loci lie within inter-genic regions. Trait-associated SNPs located in putative regulatory regions likely exert their effect by modulating gene expression. Hence, the key to unraveling the molecular mechanisms underlying cardiac traits is to interrogate variants for association with differential transcript abundance by expression quantitative trait locus (eQTL) analysis. In this study we conducted an eQTL analysis of human heart. To this end, left ventricular mycardium samples from non-diseased human donor hearts were hybridized to Illumina HumanOmniExpress BeadChips for genotyping (n = 129) and Illumina Human HT12 Version 4 BeadChips (n = 129) for transcription profiling.
Genome-wide identification of expression quantitative trait loci (eQTLs) in human heart.
Sex, Age, Specimen part
View SamplesA specialized population of memory CD8+ T-cells resides in the epithelium of the respiratory tract to maintain protection against recurring infections. These cells express CD69 and the integrin 7 (CD103) and correspond to tissue resident memory T-cells (TRM) also described in intestine, liver and brain. A less well characterized population of CD103- CD8+ T-cells also resides in lungs and expresses markers characteristic of effector memory T-cells (TEM). We determined the transcriptional profiles of these memory CD8+ T-cell subsets retrieved from human lung resection samples and compared these with corresponding T-cell populations from peripheral blood of the same individuals. Our results demonstrate that each of the populations exhibits a distinct transcriptional identity. We found that the lung environment has a major impact on gene expression profiles. Thus, transcriptomes from CD103+ and CD103- subsets from lungs are much more resemblant to one another than to those from CD103+ or CD103- memory CD8+ T-cells from blood. TRM express specific sets of chemokine receptors, in accordance with their unique migratory properties. Furthermore, these cells constitutively express cytokine and cytotoxic genes for immediate effector function and chemokines to attract auxiliary immune cells. At the same time, multiple genes encoding inhibitory regulators are also expressed. This suggests that rapid ability to unleash effector functions is counterbalanced by programmed restraint, a combination that may be critical in the exposed but delicate tissue of the lung. Comprehensive sets of transcription factors were identified that characterize the memory CD8+ populations in the lungs. Prominent among these were components of the Notch pathway. Using mice genetically lacking expression of the NOTCH1 and NOTCH2 receptors in T-cells, we demonstrated that Notch controls both the number of lung TRM as well as the function of lung TEM. Our data illustrate the adaptation of lung resident T-cells to the requirements of the respiratory epithelial environment. Defining the molecular imprinting of these cells is important for rational vaccine design and may help to improve the properties of T-cells for adoptive cellular therapy.
Programs for the persistence, vigilance and control of human CD8<sup>+</sup> lung-resident memory T cells.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Multi-OMIC profiling of survival and metabolic signaling networks in cells subjected to photodynamic therapy.
Cell line, Treatment
View Samples