Genomic studies in acute myeloid leukemias (AML) have identified mutations which drive altered DNA methylation, including TET2 and IDH. Functional studies have shown these mutations contribute to transformation, although how these mutations impact the response to epigenetic therapies is not fully delineated. Here we show AMLs with TET2/IDH2 mutations combined with FLT3ITD mutations are specifically sensitive to 5-Azacytidine or to the IDH2 inhibitor AG-221, respectively. 5-Azacytidine/AG-221 therapies induced a reduction in leukemic blasts and in stem/progenitor expansion, with attenuation of aberrant DNA hypermethylation. These therapeutic benefits were achieved through restoration of differentiation, such that normalized hematopoiesis was derived from mutant cells. Consistent with these data, at the time of clinical response to 5-Azacytidine or AG-221, most patients had mutant-derived hematopoiesis. By contrast, combined AG-221/5-Azacytidine plus FLT3 inhibition reduced disease burden and reversed epigenetic dysfunction. Our studies suggest combined targeting of signaling and epigenetic pathways can increase therapeutic response in AML. Overall design: We profiled genome-wide transcription patterns of the hematopoietic stem cells (LSK) population in Wild-type, Idh2 R140Q Flt3-ITD, and Tet2-/-;Flt3-IDT mice. Idh2 R140Q Flt3-ITD mice with AML were treated with either vehicle or AG-221 (the first small molecule in vivo inhibitor of IDH2 to enter clinical trials). Tet2-/-;Flt3-IDT mice with AML were treated with vehicle or 5-Azacytidine (Decitabine, hypomethylating agent).
Combination Targeted Therapy to Disrupt Aberrant Oncogenic Signaling and Reverse Epigenetic Dysfunction in <i>IDH2</i>- and <i>TET2</i>-Mutant Acute Myeloid Leukemia.
Specimen part, Treatment, Subject
View SamplesMalignant glioblastoma (GBM) is a highly aggressive brain tumor with a dismal prognosis and limited therapeutic options. Genomic profiling of GBM samples in the TCGA database has identified four molecular subtypes (Proneural, Neural, Classical and Mesenchymal), which may arise from different glioblastoma stem-like cell (GSC) populations. In the present study, we identify two GSC populations that produce GBM tumors by subcutaneous and intracranial injection with identical histological features. Gene expression analysis revealed that xenografts of GSCs grown as spheroid cultures had a Classical molecular subtype similar to that of bulk tumor cells. In contrast xenografts of GSCs grown as adherent cultures on laminin-coated plates expressed a Mesenchymal gene signature. Adherent GSC-derived xenografts had high STAT3 and ANGPTL4 expression as well as enrichment for stem cell markers, transcriptional networks and pro-angiogenic markers characteristic of the Mesenchymal subtype. Examination of clinical samples from GBM patients showed that STAT3 expression was directly correlated with ANGPTL4 expression, and that increased expression of these genes correlated with poor patient survival and performance. A pharmacological STAT3 inhibitor abrogated STAT3 binding to the ANGPTL4 promoter and exhibited anticancer activity in vivo. Taken together, we identified two distinct GSC populations that produce histologically identical tumors but with very different gene expression patterns, and a STAT3/ ANGPTL4 pathway in glioblastoma that may serve as a target for therapeutic intervention.
Molecular heterogeneity in a patient-derived glioblastoma xenoline is regulated by different cancer stem cell populations.
Specimen part
View SamplesThe ER alpha positive breast cancer MCF7 cells were treated with ER alpha antagonist ICI182780 in normoxia and hypoxia. Extracted RNA was subject to microarray analysis. The goal of the experiment is to assess the ICI182780 effect on breast cancer cell in both normoxia and hypoxia.
Estrogen receptor-α directly regulates the hypoxia-inducible factor 1 pathway associated with antiestrogen response in breast cancer.
Cell line
View SamplesUsing stem cellbased therapies to treat retinal abnormalities is becoming a likely possibility; therefore, identifying the key factors and the relevant mechanisms controlling optic vesicle morphogenesis and neuroretina (NR) differentiation is important. Recent advances in self-organizing, 3-dimensional (3D) tissue cultures of embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) provided a valuable in vitro model for characterizing regulatory cascades and signaling pathways controlling mammalian retinal development. Using Rx-GFP expressing ESCs and Six3/ iPSCs we identified R-spondin 2 (Rspo2)-mediated repression of Wnt signaling as a novel required step during optic vesicle morphogenesis and NR differentiation. Furthermore, we also show that transient ectopic expression of Rspo2 in the anterior neural plate of transgenic mouse embryos was sufficient to arrest NR differentiation. ChIP assays identified Six3-responsive elements in the Rspo2-promoter region, indicating that Six3-mediated repression of Rspo2 is required to restrict Wnt signaling in the developing anterior neuroectoderm and allow eye development to proceed.
An Eye Organoid Approach Identifies Six3 Suppression of R-spondin 2 as a Critical Step in Mouse Neuroretina Differentiation.
Specimen part
View SamplesMolecular signatures to improve diagnosis in PTCL and prognostication in angioimmunoblastic T-cell lymphoma (AITL). Gene expression profiling of PTCL patient samples was performed to investigate whether molecular signatures can be used to identify distinct entities of PTCL.
Molecular signatures to improve diagnosis in peripheral T-cell lymphoma and prognostication in angioimmunoblastic T-cell lymphoma.
Sex, Age, Specimen part
View SamplesHalf of prostate cancers are caused by a gene-fusion that enables androgens to drive expression of the normally silent ETS transcription factor ERG in luminal prostate cells1-4. Recent prostate cancer genomic landscape studies5-10 have reported rare but recurrent point mutations in the ETS repressor ERF11. Here we show these ERF mutations cause decreased protein stability and ERF mutant tumours are mostly exclusive from those with ERG fusions. ERF loss recapitulates the morphologic and phenotypic features of ERG gain in primary mouse prostate tissue, including expansion of the androgen receptor (AR) transcriptional repertoire, and ERF has tumour suppressor activity in the same genetic background of PTEN loss that yields oncogenic activity by ERG. Furthermore, in a human prostate cancer model of ERG gain and wild-type ERF, ChIP-seq studies indicate that ERG inhibits the ability of ERF to bind DNA at consensus ETS sites. Consistent with a competition model, ERF loss rescues ERG-positive prostate cancer cells from ERG dependency. Collectively, these data provide evidence that the oncogenicity of ERG is mediated, in part, by displacement of ERF and raise the larger question of whether other gain-of-function oncogenic transcription factors might also inactivate endogenous tumour suppressors. Overall design: Murine Pten+/+ prostates were infected with shNT or shErf lentivirus, selected with antibiotics and 2 rounds of FACS. For each condition, 2 sets of equal numbers of cells were plated and then processed for RNA extraction and RNA-seq independently.
ERF mutations reveal a balance of ETS factors controlling prostate oncogenesis.
Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Impaired tissue regeneration corresponds with altered expression of developmental genes that persists in the metabolic memory state of diabetic zebrafish.
Specimen part, Disease, Disease stage
View SamplesOlsen et al (2010) have shown that induced Diabetes mellitus (DM) in adult Zebrafish results in an impairment of tissue regeneration as monitored by caudal fin regeneration. In those studies, streptozocin was used to induce hyperglycemia in adult zebrafish, and then, following streptozocin withdrawal, a recovery phase was allowed to re-establish euglycemia, due to pancreatic b-cell regeneration. DM-associated impaired fin regeneration continued indefinitely in the metabolic memory state (MM); allowing for subsequent molecular analysis of the underlying mechanisms of MM. This study focuses on elucidating the molecular basis explaining DM-associated impaired fin regeneration and why it persists into the MM state. The analysis of microarray data indicated that of the 14,900 transcripts analyzed, aberrant expression of 71 genes relating to tissue developmental and regeneration processes were identified in DM fish and the aberrant expression of these 71 genes persisted into the MM state. Key regulatory genes of major signal transduction pathways were identified among this group of 71; and therefore, these findings provide a possible explanation for how hyperglycemia induces impaired fin regeneration and why it continues into the MM state.
Impaired tissue regeneration corresponds with altered expression of developmental genes that persists in the metabolic memory state of diabetic zebrafish.
Specimen part, Disease, Disease stage
View SamplesOlsen et al (2010) have shown that induced Diabetes mellitus (DM) in adult Zebrafish results in an impairment of tissue regeneration as monitored by caudal fin regeneration. In those studies, streptozocin was used to induce hyperglycemia in adult zebrafish, and then, following streptozocin withdrawal, a recovery phase was allowed to re-establish euglycemia, due to pancreatic b-cell regeneration. DM-associated impaired fin regeneration continued indefinitely in the metabolic memory state (MM); allowing for subsequent molecular analysis of the underlying mechanisms of MM. This study focuses on elucidating the molecular basis explaining DM-associated impaired fin regeneration and why it persists into the MM state. The analysis of microarray data indicated that of the 14,900 transcripts analyzed, aberrant expression of 71 genes relating to tissue developmental and regeneration processes were identified in DM fish and the aberrant expression of these 71 genes persisted into the MM state. Key regulatory genes of major signal transduction pathways were identified among this group of 71; and therefore, these findings provide a possible explanation for how hyperglycemia induces impaired fin regeneration and why it continues into the MM state.
Impaired tissue regeneration corresponds with altered expression of developmental genes that persists in the metabolic memory state of diabetic zebrafish.
Specimen part, Disease, Disease stage
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Identification of evolutionarily conserved gene networks mediating neurodegenerative dementia.
Age, Specimen part, Time
View Samples