Therapeutic efficacy of first-generation hypomethylating agents (HMAs) is limited in elderly acute myeloid leukemia (AML) patients. Therefore, combination strategies with targeted therapies are urgently needed. Here, we discover that priming with SGI-110 (guadecitabine), a next-generation HMA, sensitizes AML cells to ASTX660, a novel antagonist of cellular Inhibitor of Apoptosis Protein 1 and 2 (cIAP1/2) and X-linked IAP (XIAP). Importantly, SGI-110 and ASTX660 synergistically induced cell death in a panel of AML cell lines as well as in primary AML samples while largely sparing normal CD34+ human progenitor cells, underlining the translational relevance of this combination. Unbiased transcriptome analysis revealed that SGI-110 alone or in combination with ASTX660 upregulated the expression of key regulators of both extrinsic and intrinsic apoptosis signaling pathways such as TNFRSF10B (DR5), FAS and BAX. Individual knockdown of the death receptors TNFR1, DR5 and FAS significantly reduced SGI-110/ASTX660-mediated cell death, whereas blocking antibodies for TRAIL or FASLG failed to provide protection. Also, TNF-blocking antibody Enbrel had little protective effect on SGI110/ASTX660-induced cell death. Further, SGI-110 and ASTX660 acted in concert to promote cleavage of caspase-8 and BID, thereby providing a link between extrinsic and intrinsic apoptotic pathways. Consistently, sequential treatment with SGI-110 and ASTX660 triggered loss of mitochondrial membrane potential (MMP) and BAX activation, which contributes to cell death as BAX silencing significantly protected from SGI-110/ASTX660-mediated apoptosis. Together, these events culminated in activation of caspases-3/-7, nuclear fragmentation and cell death. In conclusion, SGI-110 and ASTX660 cooperatively induced apoptosis in AML cells by engaging extrinsic and intrinsic apoptosis pathways, highlighting the therapeutic potential of this combination for AML.
Next-generation hypomethylating agent SGI-110 primes acute myeloid leukemia cells to IAP antagonist by activating extrinsic and intrinsic apoptosis pathways.
Cell line
View SamplesEpithelial-mesenchymal transition (EMT) is a pivotal process in development and disease. In carcinogenesis, various signaling pathways are known to trigger EMT by inducing the expression of EMT transcription factors (EMT-TFs) like SNAIL1, ultimately promoting invasion, metastasis and chemoresistance. However, how EMT is executed downstream of EMT-TFs is incompletely understood. Here, using human colorectal cancer (CRC) and mammary cell line models of EMT, we demonstrate that SNAIL1 critically relies on bone morphogenetic protein (BMP) signaling for EMT execution. This activity requires the transcription factor SMAD4 common to BMP/TGFβ pathways, but is TGFβ signaling-independent. Further, we define a signature of BMP-dependent genes in the EMT-transcriptome which orchestrate EMT-induced invasiveness, and are found to be regulated in human CRC transcriptomes and during EMT in vivo. Collectively, our findings substantially augment the knowledge of mechanistic routes whereby EMT can be effectuated, which is relevant for the conceptual understanding and therapeutic targeting of EMT processes.
Canonical BMP Signaling Executes Epithelial-Mesenchymal Transition Downstream of SNAIL1.
Specimen part
View SamplesAims: Cardiovascular disease, one of the most common causes of death in western populations, is characterized by changes in RNA splicing and expression. Circular RNAs (circRNA) originate from back-splicing events, which link a downstream 5’ splice site to an upstream 3’ splice site. Several back-splicing junctions (BSJ) have been described in heart biopsies from human, rat and mouse hearts.[1,2] Here, we use human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) to identify circRNA and host gene dynamics in cardiac development and disease. In parallel, we explore candidate interactions of selected homologs in mouse and rat via RIP-seq experiments.Methods and Results: Deep RNA sequencing of cardiomyocyte development and ß-adrenergic stimulation uncovered 4,518 circRNAs. The set of circular RNA host genes is enriched for chromatin modifiers and GTPase activity regulators. RNA-seq and qRT-PCR data showed that circular RNA expression is highly dynamic in the hiPSC-CM model with 320 circRNAs showing significant expression changes. Intri-guingly, 82 circRNAs are independently regulated to their host genes. We validated the same circRNA dynamics for circRNAs from ATXN10, CHD7, DNAJC6 and SLC8A1 in biopsy material from human dilated cardiomyopathy (DCM) and control patients. Finally, we could show that rodent homologs of circMYOD, circSLC8A1, circATXN7 and circPHF21A interact with either the ribosome or Argonaute2 protein complexes.Conclusion: CircRNAs are dynamically expressed in a hiPSC-CM model of cardiac development and stress response. Some circRNAs show similar, host-gene inde-pendent expression dynamics in patient samples and may interact with the ribo-some and RISC complex. In summary, the hiPSC-CM model uncovered a new sig-nature of potentially disease relevant circRNAs which may serve as novel therapeu-tic targets.
No associated publication
Sex, Specimen part, Race
View SamplesThe data contains RNA sequencing data of embryonic stem cell derived cells.
No associated publication
Sex, Specimen part, Cell line
View SamplesHuman rhinovirus and influenza virus infections of the upper airway lead to colds and the flu and can trigger exacerbations of lower airway diseases including asthma and chronic obstructive pulmonary disease. Despite modest advances in the diagnosis and treatment of infections by these viruses, novel diagnostic and therapeutic targets are still needed to differentiate between the cold and the flu, since the clinical course of influenza can be severe while that of rhinovirus is usually more mild.
A systems approach to understanding human rhinovirus and influenza virus infection.
Time
View SamplesAssessment of mRNA expression levels in fat biopsies from subcutaneous adipose tissue from unrelated individuals.
A systems genetics approach implicates USF1, FADS3, and other causal candidate genes for familial combined hyperlipidemia.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Systems biology of interstitial lung diseases: integration of mRNA and microRNA expression changes.
Specimen part, Disease
View SamplesAssessment of mRNA expression levels in fat biopsies from subcutaneous adipose tissue from unrelated individuals.
Galanin preproprotein is associated with elevated plasma triglycerides.
No sample metadata fields
View SamplesPancreatic islet transplantation as a cure for type 1 diabetes (T1D) cannot be scaled up due to a scarcity of human pancreas donors. In vitro expansion of beta cells from mature human pancreatic islets provides an alternative source of insulin-producing cells. The exact nature of the expanded cells produced by diverse expansion protocols, and their potential for differentiation into functional beta cells, remain elusive. We performed a large-scale meta-analysis of gene expression in human pancreatic islet cells, which were processed using three different previously described protocols for expansion and attempted re-differentiation. All three expansion protocols induced dramatic changes in the expression profiles of pancreatic islets; many of these changes are shared among the three protocols. Attempts at re-differentiation of expanded cells induce a limited number of gene expression changes. Nevertheless, these fail to restore a pancreatic islet-like gene expression pattern. Comparison with a collection of public microarray datasets confirmed that expanded cells are highly comparable to mesenchymal stem cells. Genes induced in expanded cells are also enriched for targets of transcription factors important for pluripotency induction. The present data increases our understanding of the active pathways in expanded and re-differentiated islets. Knowledge of the mesenchymal stem cell potential may help development of drug therapeutics to restore beta cell mass in T1D patients.
Meta-analysis of gene expression in human pancreatic islets after in vitro expansion.
Specimen part
View SamplesThe mechanisms and molecular pathways underlying interstitial lung diseases (ILDs) are poorly understood. Systems biology approaches were used to identify perturbed networks in these disease states to gain a better understanding of the underlying mechanisms of disease. Through profiling genes and miRNAs, we found subsets of genes and miRNAs that distinguish different disease stages, ILDs from controls, and idiopathic pulmonary fibrosis (IPF) from non-specific interstitial pneumonitis (NSIP). Traditional pathway analysis revealed several disease-associated modules involving genes from the TGF-beta, Wnt, focal adhesion and smooth muscle actin pathways that may be involved in advancing fibrosis.
Systems biology of interstitial lung diseases: integration of mRNA and microRNA expression changes.
Specimen part, Disease
View Samples