ABSTRACT: Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are diseases of abnormal hematopoietic differentiation with aberrant epigenetic alterations. Azacitidine (AZA) is a DNA methyltransferase inhibitor (DNMTi) widely used to treat MDS and AML, yet the impact of AZA on the cell surface proteome has not been defined. To identify potential therapeutic targets for use in combination with AZA in AML patients, we investigated the effects of AZA treatment on four AML cell lines representing different stages of differentiation. The effect of AZA treatment on these cell lines was characterized at three levels: the DNA methylome, the transcriptome, and the cell surface proteome. Untreated AML cell lines showed substantial overlap at all three omics level; however, while AZA treatment globally reduced DNA methylation in all cell lines, changes in the transcriptome and surface proteome were subtle and differed among the cell lines. Transcriptome analysis identified five commonly upregulated coding genes upon AZA treatment in all four cell lines, TRPM4 being the only gene encoding a surface protein, and surface proteomics analysis found no commonly regulated proteins. Gene Set Enrichment Analysis (GSEA) of differentially-regulated RNA and surface proteins showed a decrease in metabolism pathways and an increase in immune defense response pathways. As such, AZA treatmentled to diverse effects at the individual gene and protein level but converged to common responses at the pathway level. Given the heterogeneous responses in the four cell lines, the potential therapeutic strategies for AML in combinations with AZA are discussed.
Project description:Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are diseases of abnormal hematopoietic differentiation with aberrant epigenetic alterations. Azacitidine (AZA) is a DNA methyltransferase inhibitor (DNMTi) widely used to treat MDS and AML, yet the impact of AZA on the cell surface proteome has not been defined. To identify potential therapeutic targets for use in combination with AZA in AML patients, we investigated the effects of AZA treatment on four AML cell lines representing different stages of differentiation. The effect of AZA treatment on these cell lines was characterized at three levels: the DNA methylome, the transcriptome, and the cell surface proteome. Untreated AML cell lines showed substantial overlap at all three omics level; however, while AZA treatment globally reduced DNA methylation in all cell lines, changes in the transcriptome and surface proteome were subtle and differed among the cell lines. Transcriptome analysis identified five commonly up-regulated coding genes upon AZA treatment in all four cell lines, TRPM4 being the only gene encoding a surface protein, and surface proteomics analysis found no commonly regulated proteins. Gene Set Enrichment Analysis (GSEA) of differentially-regulated RNA and surface proteins showed a decrease in metabolism pathways and an increase in immune defense response pathways. As such, AZA treatment led to diverse effects at the individual gene and protein level but converged to common responses at the pathway level. Given the heterogeneous responses in the four cell lines, we discuss potential therapeutic strategies for AML in combinations with AZA.
Project description:Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are diseases of abnormal hematopoietic differentiation with aberrant epigenetic alterations. Azacitidine (AZA) is a DNA methyltransferase inhibitor (DNMTi) widely used to treat MDS and AML, yet the impact of AZA on the cell surface proteome has not been defined. To identify potential therapeutic targets for use in combination with AZA in AML patients, we investigated the effects of AZA treatment on four AML cell lines representing different stages of differentiation. The effect of AZA treatment on these cell lines was characterized at three levels: the DNA methylome, the transcriptome, and the cell surface proteome. Untreated AML cell lines showed substantial overlap at all three omics level; however, while AZA treatment globally reduced DNA methylation in all cell lines, changes in the transcriptome and surface proteome were subtle and differed among the cell lines. Transcriptome analysis identified five commonly upregulated coding genes upon AZA treatment in all four cell lines, TRPM4 being the only gene encoding a surface protein, and surface proteomics analysis found no commonly regulated proteins. Gene Set Enrichment Analysis (GSEA) of differentially-regulated RNA and surface proteins showed a decrease in metabolism pathways and an increase in immune defense response pathways. As such, AZA treatmentled to diverse effects at the individual gene and protein level but converged to common responses at the pathway level. Given the heterogeneous responses in the four cell lines, the potential therapeutic strategies for AML in combinations with AZA are discussed.
Project description:The nucleotide analogue azacitidine (AZA) interferes with RNA and DNA metabolism and is currently the best treatment option for a subset of patients with high-risk myelodysplastic syndromes. However, only half of treated patients respond and almost all patients that initially respond eventually relapse. Thus, response-predicting biomarkers and new treatment options are urgently needed to improve the clinical management of these patients. Here, we performed a loss-of-function shRNA screen in combination with AZA treatment in a MDS-derived AML cell line to identify chromatin regulators affecting drug response. We identified the histone acetyl transferase and transcriptional co-activator CBP as a major regulator of AZA sensitivity. Compounds inhibiting the enzymatic activity of CBP synergistically reduced viability of MDS-derived AML cell lines when combined with AZA. Surprisingly, this affect was specific for the RNA-dependent functions of AZA and not observed with the related compound decitabine that is limited to DNA incorporation. The identification of immediate target genes suggested that the effect of CBP inhibition is mediated by downregulation of genes encoding the translational machinery, which could be confirmed in proteomic analysis of nascent proteins. Furthermore, proteins most affected by CBP inhibition include key drivers of cycle progression. Taken together, our results identify a novel synergistic interaction between CBP inhibitors and specifically AZA that warrants further evaluation for the combinatorial treatment of high-risk MDS patients. Beyond the scope of MDS and AZA, we provide novel insight in the function of clinically promising CBP inhibitors that is related to unexpected interference with the translational machinery.
Project description:The hypomethylating agent 5-azacytidine (AZA) is the first-line induction therapy for AML patients unsuitable for intensive chemotherapy. The anti-tumor effect of AZA results in part from T-cell cytotoxic responses against MHC-I-associated peptides (MAPs) deriving from hypermethylated genomic regions such as cancer-testis antigens (CTAs), or endogenous retroelements (EREs). However, clear evidence supporting higher ERE MAPs presentation after AZA treatment in AML is lacking. Therefore, we examined the immunopeptidome of four AML cell lines treated with AZA through a proteogenomic approach to validate this hypothesis.
Project description:Background Hypomethylating agents (HMA), such as azacytidine (AZA) and decitabine (DAC), are epigenetic therapies used to treat some patients with acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS). HMAs act in a replication-dependent manner to remove DNA methylation from the genome. However, AML cells targeted by HMA therapy are often quiescent within the bone marrow, where oxygen levels are low. In this study, we investigate the effects of hypoxia on HMA responses in AML cells. Results AML cell lines (MOLM-13, MV-4-11, HL-60) were treated with DAC (100nM) or AZA (500-2000nM) in normoxic (21% O2) and hypoxic (1% O2) conditions. Hypoxia significantly reduced AML cell growth and colony-forming capacity across all cell lines, with no additional effects observed upon HMA treatment. Hypoxia had no impact on the extent of DNA hypomethylation induced by DAC treatment, but limited AZA-induced loss of methylation from the genome. Transcriptional responses to HMA treatment were also altered, with HMAs failing to up-regulate antigen presentation pathways in hypoxia. In particular, cell surface expression of the MHC class II receptor, HLA-DR, was increased by DAC treatment in normoxia, but not hypoxia. Conclusion Our results suggest that HMA-induced antigen presentation may be impaired by hypoxia. This study highlights the need to consider microenvironmental factors when designing co-treatment strategies to improve HMA therapeutic efficacy.
Project description:Background Hypomethylating agents (HMA), such as azacytidine (AZA) and decitabine (DAC), are epigenetic therapies used to treat some patients with acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS). HMAs act in a replication-dependent manner to remove DNA methylation from the genome. However, AML cells targeted by HMA therapy are often quiescent within the bone marrow, where oxygen levels are low. In this study, we investigate the effects of hypoxia on HMA responses in AML cells. Results AML cell lines (MOLM-13, MV-4-11, HL-60) were treated with DAC (100nM) or AZA (500-2000nM) in normoxic (21% O2) and hypoxic (1% O2) conditions. Hypoxia significantly reduced AML cell growth and colony-forming capacity across all cell lines, with no additional effects observed upon HMA treatment. Hypoxia had no impact on the extent of DNA hypomethylation induced by DAC treatment, but limited AZA-induced loss of methylation from the genome. Transcriptional responses to HMA treatment were also altered, with HMAs failing to up-regulate antigen presentation pathways in hypoxia. In particular, cell surface expression of the MHC class II receptor, HLA-DR, was increased by DAC treatment in normoxia, but not hypoxia. Conclusion Our results suggest that HMA-induced antigen presentation may be impaired by hypoxia. This study highlights the need to consider microenvironmental factors when designing co-treatment strategies to improve HMA therapeutic efficacy.
Project description:This study includes 2 cohorts of samples. First cohort consists out of BM aspirates from 4 healthy individuals and 12 patients diagnosed with AML, MDS or CMML. Second cohort includes 5 healthy individuals and 17 patients diagnosed with AML, MDS or CMML. MDS and CMML patients were treated with 5-AZA on 6 cycles and samples were obtained before the treatment and 15 days after 1 and 6 rounds of treatment.
Project description:Treatment with hypomethylating agents (HMA), and specifically azacitidine (AZA), is the standard of care for patients with higher-risk myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) that are not eligible to receive intensive chemotherapy. Despite research efforts, it is not possible to predict response to treatment with HMA. In this study, we aimed to identify immune cell signatures in the bone marrow (BM) associated with treatment outcomes. By employing mass cytometry, we performed an in-depth immunophenotypic analysis in BM samples deriving from patients with myeloid neoplasms prior to treatment initiation. We identified an increased pre-treatment frequency of a CD8+ T cell subset, characterized as CD57+CXCR3+CCR7-CD45RA+, in patients with MDS and AML who did not respond to treatment with AZA, compared to responders. Furthermore, a baseline frequency of more than 29% of CD57+CXCR3+CD8+ T cells was correlated with poor overall survival. We further engaged scRNA-seq to assess the transcriptional profile of BM CD8+ T cells from treatment-naïve patients with MDS and AML, to identify molecular signatures in CD8+ T subpopulations associated with favorable outcomes. Response to treatment was positively associated with enrichment of IFN-mediated pathways coupled with enhanced cytotoxic signature, whereas enrichment of the TGF-β signaling pathway was observed in cell clusters from non-responders. Together, this study identified a specific CD57+CXCR3+ CD8+ T cell population with predictive value in patients with MDS and AML treated with AZA, and characterized molecular signatures in CD8+ T cells linked to cytokine signaling that were associated with treatment outcomes.
Project description:The whole exome sequencing experiment is part of the study: “Analysis of 5-azacytidine resistance models reveals a set of targetable pathways”. In the study we generated myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) OCI-M2 cell lines as well as patient-derived bone marrow cell lines that are resistant to hypomethylating therapy by 5-azacytidine (AZA). By integrated analysis of expression and mutation data obtained from these samples we have identified multiple signaling pathways whose modulation by specific small molecule inhibitors significantly block proliferation of AZA-resistant cell lines without increasing their sensitivity to AZA. The understanding of the molecular mechanisms which characterize the AZA-R phenotype can be used for broadening therapeutic options at progressing states during AZA therapy.
Project description:The RNA sequencing experiment is part of the study: “Modulating Redox Balance Restores Azacytidine Efficacy in Hypomethylating Agent Resistant Disease.” In the study we generated myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) OCI-M2 cell line that is resistant to hypomethylating therapy by 5-azacytidine (AZA). By modulation of the redox environment via modification of redox sensor KEAP1 using sulforaphane (SFN) in these cells we were able to restore sensitivity to AZA. We used RNA sequencing to define transcriptomic differences between AZA sensitive (AZA-S) and AZA resistant (AZA-R) cells and to characterize how the transcriptome is changing upon treatment of these cells with AZA, SFN and combination of both.