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GSE5654
Mus musculus
6 Downloadable Samples
Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Knockdown of the transcription factor PU.1 (Spi1) leads to acute myeloid leukemia (AML) in mice. We examined the transcriptome of PU.1 knockdown hematopoietic stem cells (HSC) in the preleukemic phase by linear amplification and genome-wide array analysis to identify transcriptional changes preceding malignant transformation. Hierarchical cluster analysis and principal component analysis clearly distinguished PU.1 knockdown from wildtype HSC. Jun family transcription factors c-Jun and JunB were among the top downregulated targets. Retroviral restoration of c-Jun expression in bone marrow cells of preleukemic mice partially rescued the PU.1-initiated myelomonocytic differentiation block. Lentiviral restoration of JunB at the leukemic stage led to reduced clonogenic growth, loss of leukemic self-renewal capacity, and prevented leukemia in transplanted NOD-SCID mice. Examination of 305 AML patients confirmed the correlation between PU.1 and JunB downregulation and suggests its relevance in human disease. These results delineate a transcriptional pattern that precedes the leukemic transformation in PU.1 knockdown HSC and demonstrate that decreased levels of c-Jun and JunB contribute to the development of PU.1-induced AML by blocking differentiation (c-Jun) and increasing self-renewal (JunB). Therefore, examination of disturbed gene expression in HSC can identify genes whose dysregulation is essential for leukemic stem cell function and are targets for therapeutic interventions.
Publication Title
Essential role of Jun family transcription factors in PU.1 knockdown-induced leukemic stem cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 12 Downloadable Samples
Illumina HiSeq 2500
Description
The p53 protein is the most frequently inactivated tumor suppressor in human cancer. While p53 mutations are found in 50% of all cancers, the p53 pathway can also be suppressed by its interaction with endogenous inhibitors HDMX and HDM2, which are frequently overexpressed in patients with acute myeloid leukemia and other cancers. Thus, pharmacological disruption of both these interactions is an attractive strategy to restore p53-dependent tumor suppressor activity in AML with wild type P53. Strategies targeting HDM2 have recently generated promising results; however, cancer cells are still left vulnerable to p53 inhibition by HDMX, particularly in cancers such as leukemia that overexpress HDMX. In this study, we demonstrate that dual HDMX/HDM2 inhibition using a stapled alpha-helical peptide (ALRN-6924), which has recently entered clinical testing, leads to striking anti-leukemic effects. ALRN-6924 robustly activates p53-dependent transcription at the single cell and single molecule level, and exhibits biochemical and molecular biological on-target activity in leukemia cells in vitro and in a patient who received ALRN-6924 treatment. Dual HDMX/HDM2 inhibition by ALRN-6924 inhibits cellular proliferation by inducing cell cycle arrest and apoptosis in cell lines and primary AML patients' cells, including in leukemic stem cell-enriched populations, and disrupts functional clonogenic and serial replating capacity. Furthermore, ALRN-6924 leads to significantly improved survival in an AML xenograft model in vivo. At the molecular level, dual HDMX/HDM2 inhibition leads to global transcriptional activation of p53-dependent pathways in leukemia cells. Our study provides insight into the effects of dual HDMX/HDM2 inhibition and proof-of-concept for ALRN-6924 as a novel therapeutic approach in AML and other cancers with high HDMX levels. Overall design: Total mRNA expression profiles of vehicle (1:10 DMSO) or 1 uM ALRN-6924 treated AML cells (6 hours) were generated by deep sequencing, in triplicates, using the Illumnia HiSeq 2500 instrument.
Publication Title
Dual inhibition of MDMX and MDM2 as a therapeutic strategy in leukemia.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Mus musculus, Homo sapiens
- 12 Downloadable Samples
Affymetrix Human Gene 2.0 ST Array (hugene20st)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Thrombopoietin receptor-independent stimulation of hematopoietic stem cells by eltrombopag.
Sample Metadata Fields
Age, Specimen part
View Samples- Mus musculus
- 8 Downloadable Samples
- Affymetrix Human Gene 2.0 ST Array (hugene20st)
Description
Eltrombopag, a small molecule thrombopoietin receptor (TPO-R) agonist and potent intracellular iron chelator, has shown remarkable efficacy to stimulate sustained multilineage hematopoiesis in patients with bone marrow failure syndromes, suggesting an effect at the most immature hematopoietic stem and multipotent progenitor level. While the functional and molecular effects of Eltrombopag on megakaryopoiesis have been carefully studied in the recent past, insights into its mechanistic impact on the earliest stages of hematopoiesis have been limited. Additionally, previous studies also revealed molecular pathway of Eltrombopag apart from stimulation of TPO signaling, detail characterization remains to be addressed. In this study, we investigated the effects of Eltrombopag, in comparison with TPO, on highly-purified primary hematopoietic stem cells (HSCs) from healthy human donors. The binding of Eltrombopag to TPO-R is species-specific to human and primate cells. we also utilized HSCs isolated mouse as separation-of-function models to directly assess the molecular effect of Eltrombopag on HSCs independent of TPOR stimulation.
Publication Title
Thrombopoietin receptor-independent stimulation of hematopoietic stem cells by eltrombopag.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 27 Downloadable Samples
- NextSeq 500
Description
We report RNA Seq analysis using Illumina nextSeq500 of human beta cells EndoC-BH1 treated with FGF2 to induce dedifferentiation. FGF2 treatment induced dedifferentiation of EndoC-BH1 cells. Indeed, we observed a strong decrease in expression of ß-cell markers, (INS, MAFB, SLC2A2, SLC30A8 and GCK). Opposingly, we identifed positive markers of human ß cell dedifferentiation, as attested by increased expression of mature ß-cell disallowed transcription factors (MYC, HES1, SOX9 and NEUROG3). Interestingly, our temporal analysis revealed that loss of expression of ß cell specific markers preceded the induction of ß cell disallowed genes. Overall design: human beta cells EndoC-BH1 were treated with FGF2 (100ng/L) during 4, 24, 72 and 144h. RNA was isolated post treatment, along with the non-treated controls, and RNA Seq was performed using Illumina nextSeq500 to generate a full transcriptome analysis of gene expression during dedifferentiation of pancreatic beta cells.
Publication Title
Modeling human pancreatic beta cell dedifferentiation.
Sample Metadata Fields
Specimen part, Cell line, Subject, Time
View Samples