In chronic lymphocytic leukemia (CLL), 13q14 and 11q22-23 deletions are found in 2/3 of the cases. 11q22-23 deletions are associated with poor survival, whereas 13q14 deletions as single abnormality are often found in indolent disease forms. The molecular basis for this difference in prognosis is not known.
Expression analysis of genes located in the minimally deleted regions of 13q14 and 11q22-23 in chronic lymphocytic leukemia-unexpected expression pattern of the RHO GTPase activator ARHGAP20.
Specimen part, Disease, Disease stage
View SamplesPurpose: CEBPA mutations are found as either biallelic (biCEBPA) or monoallelic (moCEBPA). We set out to explore whether the kind of CEBPA mutation is of prognostic relevance in cytogenetically normal AML (CN-AML).
Acute myeloid leukemia with biallelic CEBPA gene mutations and normal karyotype represents a distinct genetic entity associated with a favorable clinical outcome.
Specimen part
View SamplesThe alarmins myeloid-related protein (MRP) 8 and MRP14 are the dominant cytoplasmic proteins in phagocytes. After release by activated phagocytes extracellular MRP8/MRP14 complexes promote inflammation in many diseases, including infections, allergies, autoimmune diseases, rheumatoid arthritis or inflammatory bowel disease. As receptors for the pro-inflammatory effects of human MRP8, the active component of the MRP8/MRP14-complex, Toll-like receptor (TLR) 4 and the multi-ligand receptor of advanced glycation end products (RAGE) are controversial discussed. Using a comparative bioinformatics analysis between genome-wide response patterns of monocytes to MRP8, endotoxin and different cytokines we demonstrated a dominant role of TLR4 during MRP8-mediated phagocyte activation. The relevance of this signaling pathway could be confirmed in independent cell models for TLR4 and RAGE dependent signaling in mouse and man. In addition to well-known proinflammatory functions of MRP8 our systems biology approach unraveled a novel anti-apoptotic effect of MRP8 on monocytes which was confirmed in independent functional experiments. Our data define the dominance of the TLR4-MRP8 axis in activation of human phagocytes which represents a novel attractive target for modulation of overwhelming innate immune responses.
Transcriptome assessment reveals a dominant role for TLR4 in the activation of human monocytes by the alarmin MRP8.
Specimen part, Treatment
View SamplesGlucocorticoids (GC) are used as first line therapies for generalized suppression of inflammation (e.g. allergies or autoimmune diseases), but their long-term use is limited by severe side effects. Our previous work has revealed that GC induced a stable anti-inflammatory phenotype in monocytes, the glucocorticoid-stimulated monocytes (GCsM) that we now exploited for targeted GC-mediated therapeutic effects.
Immune suppression via glucocorticoid-stimulated monocytes: a novel mechanism to cope with inflammation.
Specimen part, Treatment
View SamplesThe biology of chronic myeloid leukemia (CML)-stem cells is still incompletely understood. Therefore, we previously developed an inducible transgenic mouse model in which stem cell targeted induction of BCR-ABL expression leads to chronic phase CML-like disease. Here, we now demonstrate that the disease is transplantable using BCR-ABL positive LSK cells (lin-Sca-1+c-kit+). Interestingly, the phenotype is enhanced when unfractionated bone marrow (BM) cells are transplanted. However, neither progenitor cells (lin-Sca-1-c-kit+) nor mature granulocytes (CD11b+Gr-1+), or potential stem cell niche cells were able to transmit the disease or alter the phenotype. The phenotype was largely independent of BCR ABL priming prior to transplant. However, BCR-ABL abrogated the potential of LSK cells to induce full blown disease in secondary recipients. Subsequently, we found that BCR-ABL increased the fraction of multipotent progenitor cells (MPP) at the expense of long term HSC (LT-HSC) in the BM. Microarray analyses of LSK cells revealed that BCR-ABL alters the expression of genes involved in proliferation, survival, and hematopoietic development. Our results suggest that BCR-ABL induces differentiation of LT-HSC and decreases their self renewal capacity. Furthermore, reversion of BCR-ABL eradicates mature cells while leukemic stem cells persist, giving rise to relapsed CML upon re-induction of BCR-ABL.
BCR-ABL enhances differentiation of long-term repopulating hematopoietic stem cells.
Specimen part
View SamplesChronic lymphocytic leukemia (CLL) is a common and heterogeneous disease. An accurate prediction of outcome is highly relevant for the development of personalized treatment strategies. Microarray technology was shown to be a useful tool for the development of prognostic gene expression scores. However, there are no gene expression scores which are able to predict overall survival in CLL based on the expression of few genes that are better than established prognostic markers. We correlated 151 CLL microarray data sets with overall survival using Cox regression and supervised principal component analysis to derive a prognostic score. This score based on the expression levels of eight genes and was validated in an independent group of 149 CLL patients by quantitative real time PCR. The score was predictive for overall survival and time to treatment in univariate Cox regression in the validation data set (both: p<0.001) and in a multivariate analysis after adjustment for 17p and 11q deletions and the IgVH-status. The score achieved superior prognostic accuracy compared to models based on genomic aberrations and IgVH-status and may support personalized therapy.
An eight-gene expression signature for the prediction of survival and time to treatment in chronic lymphocytic leukemia.
Specimen part, Disease, Disease stage
View SamplesThe translocation t(10,11)(p13;q14) resulting in the formation of the CALM/AF10 fusion gene is involved in various hematological malignancies including acute myeloid leukemia, T-cell acute lymphoblastic leukemia, and malignant lymphoma and is usually associated with poor prognosis. We established a knock-in mouse model allowing tissue-specific CALM/AF10 expression from the Rosa26 locus using a loxP-STOP-loxP cassette to study leukemic transformation by the CALM/AF10 fusion protein during hematopoiesis. vav-Cre induced pan-hematopoietic expression of the CALM/AF10 fusion gene led to acute leukemia with a median latency of 12 months. Leukemias were either myeloid or had myeloid feature and showed expression of the B cell marker B220. Gene expression profiling of leukemic bone marrow cells revealed the overexpression of Hoxa cluster genes and the Hox co-factor Meis1. The long latency to leukemia development suggested that additional, collaborative genetic lesions are required. We identified an average of 2 to 3 additional mutations per leukemia using whole-exome sequencing. When CALM/AF10 was expressed in the B lymphoid compartment using mb1-Cre or CD19-Cre inducer lines no leukemia development was observed. Our results indicate that CALM/AF10 needs to be expressed from the stem or early progenitor cell stage onward to permit the acquisition of additional mutations required for leukemic transformation.
The target cell of transformation is distinct from the leukemia stem cell in murine CALM/AF10 leukemia models.
Disease
View SamplesExamination of gene expression patterns in lineage negative FLT3-ITD and pMIG-transduced BM cells via microarray study.
RIPK3 Restricts Myeloid Leukemogenesis by Promoting Cell Death and Differentiation of Leukemia Initiating Cells.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Adults with Philadelphia chromosome-like acute lymphoblastic leukemia frequently have IGH-CRLF2 and JAK2 mutations, persistence of minimal residual disease and poor prognosis.
Specimen part, Disease, Disease stage
View SamplesPhiladelphia-like B-cell precursor acute lymphoblastic leukemia (Ph-like ALL) is characterized by distinct genetic alterations and inferior prognosis in children and younger adults. The purpose of this study was the genetic and clinical characterization of Ph-like ALL in adults. Among 207 adult B-cell precursor ALL patients, 26 (13%) were classified as Ph-like using Affymetrix microarrays. The incidence of this subtype was 25% among 105 B-cell precursor ALL patients negative for BCR-ABL1 and MLL-translocations (B-other). All patients with IgH-CRLF2 translocation (38% vs 0%; p=0.002) or mutations in JAK2 (44% vs. 0%; p<0.001) were exclusively found in the Ph-like subgroup. Clinical and outcome analyses were restricted to patients treated within GMALL trials 06/99 and 07/03 (n=107). The complete remission (CR) rate after induction was 100% for Ph-like (n=19) and B-other patients (n=40). After induction, significantly fewer Ph-like patients reached molecular CR (33% vs 79%; p=0.01). At 5 years, the Ph-like ALL subgroup had a lower probability of continuous CR (24% vs 62%; p<0.001) and overall survival (22% vs 64%; p=0.006) compared to B-other ALL patients. Subsequent analysis led to a clinically applicable algorithm identifying this patient subset with a specificity of 100%. Our study is the first to demonstrate that the profile of genetic events in adult Ph-like ALL resembles pediatric Ph-like ALL and differs from B-other ALL. The Ph-like phenotype associates with inferior outcomes in intensively treated adult ALL patients. Ph-like adult ALL should be recognized as a distinct, high-risk entity and further research on improved diagnostic and therapeutic approaches is needed.
Adults with Philadelphia chromosome-like acute lymphoblastic leukemia frequently have IGH-CRLF2 and JAK2 mutations, persistence of minimal residual disease and poor prognosis.
Specimen part, Disease, Disease stage
View Samples