Post-chemotherapy relapse presents a major unmet medical need in AML where treatment options are limited. We used gene expression profile from 32 AML cell lines to characterize expression difference between responder and non-responders to PIM inhibitors. Our results highlight the importance of STAT5 and MYC in rendering cancer cells sensitive to PIM inhibitors.
No associated publication
Cell line
View SamplesHepatocellular carcinoma (HCC) remains a significant clinical challenge with few therapeutic options available to cancer patients. MicroRNA 21-5p (miR-21) has been shown to be upregulated in HCC, but the contribution of this oncomiR to the maintenance of tumorigenic phenotype in liver cancer remains poorly understood. We have developed potent and specific single-stranded oligonucleotide inhibitors of miR-21 (anti-miRs) and used them to interrogate dependency on miR-21 in a panel of liver cancer cell lines. Treatment with anti-miR-21, but not with a mismatch control anti-miR, resulted in significant de-repression of direct targets of miR-21 and led to loss of viability in the majority of HCC cell lines tested. Robust induction of caspase activity, apoptosis and necrosis was noted in anti-miR-21 treated HCC cells. Furthermore, ablation of miR-21 activity resulted in inhibition of HCC cell migration and suppression of clonogenic growth. To better understand the consequences of miR-21
Anti-miR-21 Suppresses Hepatocellular Carcinoma Growth via Broad Transcriptional Network Deregulation.
Cell line
View SamplesThe most frequent genetic alterations in melanoma are gain-of-function mutations in BRAF, which result in addiction to the RAF-MEK-ERK signaling pathway. Despite success of RAF and MEK inhibitors in treating BRAFV600 mutant tumors, a major challenge is the inevitable emergence of drug resistance, which often involves reactivation of the MAPK pathway. Interestingly, resistant tumors are often sensitive to drug withdrawal, suggesting that hyperactivation of the MAPK pathway is not tolerated. To further characterize this phenomenon, we generated isogenic models of inducible MAPK hyperactivation in BRAFV600E melanoma cells by overexpression of ERK2. Using this model system, we demonstrated that supra-physiological levels of MAPK signaling led to cell death, which was reversed by MAPK inhibitors. Whereas MAPK pathway inhibition led to cell stasis in BRAFV600E melanoma cells, MAPK hyperactivation induced cytotoxicity. Furthermore, complete tumor regression was observed in an ERK2 overexpressing xenograft model. To identify mediators of MAPK hyperactivation- induced cell death, we conducted a large-scale pooled screen which showed that only shRNAs against BRAF and MAP2K1 rescued loss of cell viability. This suggested that no single downstream ERK2 effector was required, consistent with pleiotropic effects on multiple cellular stress pathways. Intriguingly, the detrimental effect of MAPK hyperactivation could be partially attributed to secreted factors, and more than 100 differentially secreted proteins were identified. The effect of ERK2 overexpression was highly context dependent, as RAS/RAF mutant but not RAS/RAF wildtype melanoma were sensitive to this perturbation. This vulnerability to MAPK hyperactivation raises the possibility of a novel therapeutic approach for RAS/RAF mutant cancers.
No associated publication
Sex, Specimen part, Disease, Cell line, Treatment
View SamplesWe established gene expression profiles of diagnostic bone marrow samples of monozygotic twins with acute lymphoblastic leukemia. We established technical duplicates for each twin.
Prenatal origin of separate evolution of leukemia in identical twins.
Sex, Specimen part, Disease, Disease stage
View SamplesThe activation of the transcription factor NF-E2-related factor 2 (Nrf2) maintains cellular homeostasis in response to oxidative stress by the regulation of multiple cytoprotective genes. Without stressors the activity of Nrf2 is inhibited by its interaction with the kelch-like ECH-associated protein 1 (Keap1). Here, we describe RA839, a small molecule that binds non-covalently to the Nrf2-interacting kelch domain of Keap1 with a Kd of approximately 6 M, as demonstrated by X-ray co-crystallization and isothermal titration calorimetry. Whole-genome DNA arrays showed that at 10 M RA839 significantly regulated 105 genes in bone marrow-derived macrophages. Canonical pathway mapping of these genes revealed an activation of pathways linked with Nrf2 signalling. These pathways were also activated after the activation of Nrf2 by the silencing of Keap1 expression. RA839 regulated only two genes in Nrf2 knockout macrophages. Similar to the activation of Nrf2 by either silencing of Keap1 expression or by the reactive compound CDDO-Me, RA839 prevented the induction of both inducible nitric oxide synthase expression and nitric oxide release in response to lipopolysaccharides in macrophages. In mice RA839 acutely induced Nrf2-target gene expression in liver. RA839 is a selective inhibitor of the Keap1/Nrf2 interaction and a useful tool compound to study the biology of Nrf2.
Characterization of RA839, a Noncovalent Small Molecule Binder to Keap1 and Selective Activator of Nrf2 Signaling.
Specimen part, Treatment
View SamplesThe transcription factor NF-E2-related factor 2 (Nrf2) induces cytoprotective genes, but has also been linked to the regulation of hepatic energy metabolism. In order to assess the pharmacological potential of hepatic Nrf2 activation in metabolic disease, Nrf2 was activated over 8 weeks in mice on Western diet using two different siRNAs against kelch-like ECH-associated protein 1 (Keap1), the inhibitory protein of Nrf2. Whole genome expression analysis followed by pathway analysis demonstrated that the suppression of Keap1 expression induced genes that are involved in anti-oxidative stress defense and biotransformation, pathways proving the activation of Nrf2 by the siRNAs against Keap1. The expression of neither fatty acid- nor carbohydrate-handling proteins was regulated by the suppression of Keap1. Metabolic profiling of the animals did also not show effects on plasma and hepatic lipids, energy expenditure or glucose tolerance by the activation of Nrf2. The data indicate that hepatic Nrf2 is not a major regulator of intermediary metabolism in mice.
Chronic Activation of Hepatic Nrf2 Has No Major Effect on Fatty Acid and Glucose Metabolism in Adult Mice.
Specimen part, Treatment
View SamplesHistone deacetylases (HDACs) are important regulators of epigenetic gene modification that are involved in the transcriptional control of metabolism. In particular class IIa HDACs have been shown to affect hepatic gluconeogenesis and previous approaches revealed that their inhibition reduces blood glucose in type 2 diabetic mice. In the present study, we aimed to evaluate the potential of class IIa HDAC inhibition as a therapeutic opportunity for the treatment of metabolic diseases. For that, siRNAs selectively targeting HDAC4, 5 and 7 were selected and used to achieve a combinatorial knockdown of these three class IIa HDAC isoforms. Subsequently, the hepatocellular effects as well as the impact on glucose and lipid metabolism were analyzed in vitro and in vivo. The triple knockdown resulted in a statistically significant decrease of gluconeogenic gene expression in a murine hepatic cell line as well as in human primary hepatocytes. Despite a similar HDAC-induced downregulation of hepatic genes involved in gluconeogenesis in mice using a liver-specific lipid nanoparticle siRNA formulation, the in vivo effects on whole body glucose metabolism were only limited and did not outweigh the safety concerns observed by histopathological analysis in spleen and kidney. Mechanistically, Affymetrix gene chip analysis and gene expression studies provide evidence that class IIa HDACs directly target and thus regulate the expression of HNF4α and FOXP1 in the liver, thereby modifying gene regulatory mechanisms mediating glucose and lipid metabolism and transport. In conclusion, the combinatorial knockdown of HDAC4, 5 and 7 by therapeutic siRNAs affected multiple pathways in vitro and in vivo leading to the downregulation of genes involved in gluconeogenesis. However, the effects on the gene expression level were not paralleled by a significant reduction of gluconeogenesis in mice, as shown in pyruvate tolerance tests. However, the liver-specific inhibition of these HDAC isoforms was associated with severe adverse effects in vivo, making this approach not a viable treatment option for chronic metabolic disorders like type 2 diabetes.
No associated publication
Specimen part
View SamplesTo facilitate preclinical translational science, this cohort of patient-derived xenograft (PDX) models of leukemia and lymphoma has undergone molecular characterization with whole transcriptome sequencing, targeted exon sequencing of genes recurrently altered in leukemia and lymphoma, and other approaches. Here we provide the whole transcriptome sequencing data for these PDX models. Related molecular data and de-identified clinical information can be obtained at http://www.proxe.org.
No associated publication
No sample metadata fields
View SamplesMAP3K11 overexpression in tumors leads to weight loss in the host
No associated publication
Specimen part
View SamplesTotal RNA sequencing data from primary colorectal tumors, liver metastasis and patient derived xenographs. Persistence of Fusobacterium and co-occuring anaerobic bacteria in human colorectal cancer.
No associated publication
No sample metadata fields
View Samples