STAT5A and STAT5B proteins belong to the family of signal transducers and activators of transcription. They are encoded by 2 separate genes with 91% identity in their amino acid sequences. Despite their high degree of conservation, STAT5A and STAT5B exert non-redundant functions, resulting at least in part from differences in target gene activation. To better characterize the differential contribution of STAT5A and STAT5B in gene regulation, we performed single or double knock-down of STAT5A and STAT5B using small interfering RNA. Subsequent gene expression profiling and RT-qPCR analyses of IL-3-stimulated Ba/F3-beta cells led to the identification of putative novel STAT5 target genes. Chromatin immunoprecipitation assays analyzing the corresponding gene loci identified unusual STAT5 binding sites compared to conventional STAT5 responsive elements. Some of the STAT5 targets identified are upregulated in several human cancers, suggesting that they might represent potential oncogenes in STAT5-associated malignancies.
In vivo identification of novel STAT5 target genes.
No sample metadata fields
View SamplesAberrant activation of -catenin is a common event in Acute Myeloid Leukemia (AML), and is recognized as an independent predictor of poor prognosis. Although increased -catenin signaling in AML has been associated with AML1-ETO and PML-RAR translocation products, and activating mutations in the FLT3 receptor, it remains unclear which mechanisms activate -catenin in AML more broadly. Here, we describe a novel link between interleukin-3 (IL-3) signaling and the regulation of -catenin in myeloid transformation and AML. Using a murine model of HoxB8 and IL-3 cooperation we show that IL-3 modulates -catenin protein levels, and Cre-induced deletion of -catenin abolishes IL-3 dependent growth and colony formation. In the erythroleukemic cell line TF-1.8, we observed increased -catenin protein levels and nuclear localization in response to IL-3, which correlated with transcriptional induction of -catenin target genes. Furthermore, IL-3 promoted -catenin accumulation in a subset of AML patient samples, and microarray gene expression analysis of these cells revealed induction of WNT/-catenin and TCF4 transcriptional gene signatures in an IL-3 dependent manner. This study is the first to link -catenin activation to IL-3 and suggests that targeting IL-3 signaling may be an effective approach for the inhibition of -catenin activity in some patients with AML.
Interleukin-3-mediated regulation of β-catenin in myeloid transformation and acute myeloid leukemia.
Specimen part, Disease, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Ecotopic viral integration site 1 (EVI1) regulates multiple cellular processes important for cancer and is a synergistic partner for FOS protein in invasive tumors.
Specimen part, Cell line
View SamplesHere we compare the effects of stimulation on cord blood derived CD4+ CD25+ (Treg) and CD4+ CD25- (Thelper) cells, isolated by MACS protocols & expanded in vitro using dynabeads. Expansion was carried out at a ratio of 3 beads/cell in the presence of 1000units/ml of recombinant human IL2 for 8 days, followed by 3 days of culture without beads.
Genome-wide identification of human FOXP3 target genes in natural regulatory T cells.
Specimen part, Treatment
View SamplesWe studied the variations of mRNA amounts after Evi1 knockdown or Flag-Evi1 overexpression in SKOV-3 cells.
Ecotopic viral integration site 1 (EVI1) regulates multiple cellular processes important for cancer and is a synergistic partner for FOS protein in invasive tumors.
Cell line
View SamplesWe studied the variations of mRNA amounts after Flag-EVI1 or Flag expression in HeLa cells.
Ecotopic viral integration site 1 (EVI1) regulates multiple cellular processes important for cancer and is a synergistic partner for FOS protein in invasive tumors.
Cell line
View SamplesThis study has examined the molecular mechanisms underlying sensitivity of sarcomas to Nutlin-3a, a non-genotoxic activator of the p53 pathway. Human patient material was collected immediately following surgical resection, dissected into small pieces and ex planted onto gelatin sponges immersed in media containing either vehicle control or Nutlin-3a (10uM and/or 50uM) for 48 hours.
Nutlin-3a efficacy in sarcoma predicted by transcriptomic and epigenetic profiling.
No sample metadata fields
View SamplesGATA2 mutants were discovered in families predisposed to MDS/AML and in sporadic cases of CML-blast crisis. Promyelocytic HL-60 cells were transduced with lentiviral vectors that express GATA2 WT or T354M, 355delT or L359V mutants upon addition of 4-hydroxy tamoxifen (4HT). Microarrays were performed to identify GATA2 WT signatures and differences caused by these mutations.
Heritable GATA2 mutations associated with familial myelodysplastic syndrome and acute myeloid leukemia.
Specimen part, Cell line
View SamplesFollowing androgen ablation therapy (AAT), the vast majority of prostate cancer patients develop treatment resistance with a median time of 18-24 months to disease progression. To identify molecular targets that aid in prostate cancer cell survival and contribute to the androgen independent phenotype, we evaluated changes in LNCaP cell gene expression during 12 months of androgen deprivation. At time points reflecting critical growth and phenotypic changes, we performed Affymetrix expression array analysis to examine the effects of androgen deprivation during the acute response, during the period of apparent quiescence, and during the emergence of highly proliferative, androgen-independent prostate cancer cells (LNCaP-AI). We discovered alterations in gene expression for a host of molecules associated with promoting prostate cancer cell growth and survival, regulating cell cycle progression, apoptosis and adrenal androgen metabolism, in addition to AR co-regulators and markers of neuroendocrine disease. These findings illustrate the complexity and unpredictable nature of cancer cell biology and contribute greatly to our understanding of how prostate cancer cells likely survive AAT. The value of this longitudinal approach lies in the ability to examine gene expression changes throughout the cellular response to androgen deprivation; it provides a more dynamic illustration of those genes which contribute to disease progression in addition to specific genes which constitute a malignant androgen-independent phenotype. In conclusion, it is of great importance that we employ new approaches, such as the one proposed here, to continue exploring the cellular mechanisms of therapy resistance and identify promising targets to improve cancer therapeutics.
Longitudinal analysis of androgen deprivation of prostate cancer cells identifies pathways to androgen independence.
No sample metadata fields
View SamplesWe have generated mouse models of real CMT1B mutations in the gene encoding for myelin protein zero (P0). One of these mutants, P0S63del is retained in the ER where it elicits an unfolded protein response (UPR). Genetic ablation of the UPR factor CHOP restores the motor capacity in S63del mice. We used microarray to decipher the molecular mechanism undelying the P0S63del neuropathy and the rescue in S63del/Chop null nerves.
Resetting translational homeostasis restores myelination in Charcot-Marie-Tooth disease type 1B mice.
Age, Specimen part
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