Although the prognosis for childhood Acute Lymphoblastic Leukemia (ALL) in general has improved tremendously over the last decades, the survival chances for infants (<1 year of age) with ALL remains poor.
Association of high-level MCL-1 expression with in vitro and in vivo prednisone resistance in MLL-rearranged infant acute lymphoblastic leukemia.
Sex, Specimen part, Disease
View SamplesIn high income countries 90% of the patients achieve complete remission after induction chemotherapy. However, 30-40% of these patients suffer from relapse. These patients face a dismal prognosis, as the majority (>60%) of relapsed patients die within 5 years. As a result, outcome for pediatric acute myeloid leukemia (AML) patients remains poor and has stabilized over the past 15 years. To prevent or better treat relapse of AML is the best option to improve outcome. Despite patient specific differences, most patients do respond to initial therapy. This suggests that at relapse, mechanisms are active that cause the altered response to chemotherapy. Detailed understanding of mechanisms that cause relapse remain largely elusive. To gain insight in the molecular pathways that characterize relapsed AML, we performed genome wide gene expression profiling on paired initial diagnosis and relapsed AML samples of 23 pediatric AML patients. We used pathway analysis to find which molecular pathways are involved in altered gene expression between diagnosis and relapse samples of individual AML patients.
Gene expression profiles associated with pediatric relapsed AML.
Disease
View SamplesCombined overexpression of miR-125b with miR-99a and/or miR-100 induced VCR resistance in ETV6-RUNX1-positive leukemic cells Reh.
MiR-125b, miR-100 and miR-99a co-regulate vincristine resistance in childhood acute lymphoblastic leukemia.
Disease, Cell line
View SamplesHigh VEGFC mRNA expression of AML blasts is related to increased in vitro and in vivo drug resistance. The prognostic significance of VEGFC on long-term outcome and its associated gene expression profiles remain to be defined. We studied the effect of VEGFC on treatment outcome and investigated gene expression profiles associated with VEGFC using microarray data of 525 adult and 100 pediatric AML patients. High VEGFC expression appeared strongly associated with reduced complete remission rate, reduced overall and event-free survival (OS and EFS) in adult AML. Multivariable analysis established high VEGFC as prognostic indicator independent of cytogenetic risk, FLT3-ITD, NPM1, CEBPA, age and WBC. Also in pediatric AML high VEGFC was related to reduced OS. A unique series of differentially expressed genes was identified that distinguished AML with high VEGFC from AML with low VEGFC, i.e., 331 upregulated genes (representative of proliferation, VEGF-receptor activity, signal transduction) and 44 downregulated genes (e.g. related to apoptosis) consistent with a role in enhanced chemoresistance. In conclusion, high VEGFC predicts adverse long-term prognosis and provides prognostic information in addition to well-known prognostic factors.
High VEGFC expression is associated with unique gene expression profiles and predicts adverse prognosis in pediatric and adult acute myeloid leukemia.
Specimen part, Subject
View SamplesPAX5-JAK2 has recently been identified as a novel recurrent fusion gene in B-cell precursor acute lymphoblastic leukemia (BCP-ALL) but the function of the encoded chimeric protein has not yet been characterized in detail. Herein we show that the PAX5-JAK2 chimera, which consists of the DNA-binding paired domain of PAX5 and the active kinase domain of JAK2, is a nuclear protein that has the ability to bind to wild-type PAX5 target loci. Moreover, our data provide compelling evidence that PAX5-JAK2 functions as nuclear catalytically active kinase that autophosphorylates and in turn phosphorylates and activates downstream STATs in an apparently non-canonical mode. The chimeric protein also enables cytokine-independent growth of Ba/F3 cells and, therefore, possessing transforming potential. Importantly, the kinase activity of PAX5-JAK2 can be efficiently blocked by JAK2 inhibitors rendering it a potential target for therapeutic intervention. Together, our data show that PAX5-JAK2 simultaneously deregulates the PAX5 downstream transcriptional program and activates the JAK-STAT signaling cascade, and thus, by interfering with these two important pathways, may promote leukemogenesis.
The role of the Janus-faced transcription factor PAX5-JAK2 in acute lymphoblastic leukemia.
Specimen part, Disease, Disease stage
View SamplesTitle: Transcriptome analysis of human endometrial tissues from healthy post-menoupausal women reflecting the endometrial response to 3-weeks treatment with tibolone, E2 and E2+MPA.
Molecular analysis of human endometrium: short-term tibolone signaling differs significantly from estrogen and estrogen + progestagen signaling.
No sample metadata fields
View SamplesTo examine Ikaros tumor suppressor mechanisms, we have utilized inducible RNAi to dynamically restore endogenous Ikaros expression in BCR-ABL1+ B-ALL driven by its knockdown (Ikaros knockdown), and compared these tumors to tumors driven by BCR-ABL1 alone (control). Restoration of Ikaros causes rapid regression of tumor cells in vivo, significantly prolonging tumor transplant recipient survival. Using both transgenic and retroviral approaches, we conducted expression analysis of B-ALL by RNA-Seq and have identified a series of Ikaros-regulated genes within established tumor cell in vivo. Comparison of Ikaros-activated and Ikaros-repressed genes with human B-ALL expression data shows a set of conserved Ikaros target genes, some of which are associated with patient outcome (namely, CTNND1, IFITM3 and EMP1). Overall design: RNA-seq was performed on BCR-ABL1+ B-ALL with inducible Ikaros knockdown (Ikaros knockdown, n=8; transgenic n=5, retroviral n=3) or BCR-ABL1+ alone B-ALL (control, n=4; transgenic n=3, retroviral n=1) cells isolated from untreated and three 3-day Dox-treated mice. Samples were run on HiSeq or NextSeq platform. B-ALL B031 was run in technical duplicate. Extended Dox samples (B027: d7 and d10) and relapse samples for B027, B029 and B035 have also been analyzed in this dataset.
Conserved IKAROS-regulated genes associated with B-progenitor acute lymphoblastic leukemia outcome.
Specimen part, Treatment, Subject
View SamplesThis file contains the expression data for pediatric medulloblastomas and ependymomas
Differential expression and prognostic significance of SOX genes in pediatric medulloblastoma and ependymoma identified by microarray analysis.
Specimen part
View SamplesAcute lymphoblastic leukemia (ALL) can be cured with combination chemotherapy in over 75% of children, but the cause of treatment failure in the remaining patients is unknown. We determined the sensitivity of ALL cells to individual antileukemic agents in 441 patients, and used a genome-wide approach to identify 45 genes differentially expressed in ALL exhibiting cross-resistance to prednisolone, vincristine, asparaginase and daunorubicin. We also identified a distinct phenotype of discordant resistance to asparaginase and vincristine and 139 genes whose expression was associated with this novel phenotype. The expression of these genes discriminated treatment outcome in two independent patient populations, identifying a subset of patients with a markedly inferior outcome (37%13% 5-year DFS).
Identification of genes associated with chemotherapy crossresistance and treatment response in childhood acute lymphoblastic leukemia.
No sample metadata fields
View SamplesPediatric acute myeloid leukemia (AML) is a heterogeneous disease characterized by non-random genetic aberrations related to outcome. Detecting these aberrations however still lead to failures or false negative results. Therefore, we focused on the potential of gene expression profiles (GEP) to classify pediatric AML.
Evaluation of gene expression signatures predictive of cytogenetic and molecular subtypes of pediatric acute myeloid leukemia.
Specimen part, Subject
View Samples