Project description:Genotoxicants have been used for decades as front-line therapies against cancer on the basis of their DNA-damaging actions. However, some of their non-DNA-damaging effects are also instrumental for killing dividing cells. We report here that the anthracycline Daunorubicin (DNR) but not the nucleoside analog Cytarabine, the two main drugs used to treat Acute Myeloid Leukemia (AML), induces rapid (3 hours) and broad transcriptional changes in AML cells. The regulated genes are particularly enriched in genes controlling cell proliferation and death, as well as inflammation and immunity. These transcriptional changes are preceded by DNR-dependent deSUMOylation of chromatin proteins, in particular at active promoters and enhancers. Surprisingly, accelerating deSUMOylation dampens DNR-induced transcriptional reprogramming. Quantitative proteomics shows that proteins that are deSUMOylated in response to DNR are mostly transcription factors, transcriptional co-regulators and chromatin organizers. Among them, the CCCTC-binding factor CTCF is highly enriched at SUMO-binding sites found in cis-regulatory regions. This is notably the case at the promoter of the DNR-induced NFKB2 gene. Although DNR does not modify CTCF binding on chromatin in general and at NFKB2 promoter in particular, it leads to a SUMO-dependent reconfiguration of chromatin loops engaging CTCF- and SUMO-bound NFKB2 promoter with distal cis-regulatory regions.
Project description:Acute Myeloid Leukemia cell line HL-60 were treated with 1 M daunorubicin (DNR) or 2M cytarabin (Ara-C) or 1 M DNR + 10 M VAS2870 (NADPH oxidase inhibitor) for 2 hours. ChIP-Seq experiments were carried out with SUMO-2/3 antibodies. Immunoprecipitated DNA and corresponding inputs from 3 independent experiments were pooled and processed for deep-sequencing (Hi-SEq 2000, Illumina).
Project description:Genotoxicants have been used for decades as front-line therapies against cancer on the basis of their DNA-damaging actions. However, some of their non-DNA-damaging effects are also instrumental for killing dividing cells. We report here that the anthracycline Daunorubicin (DNR), one of the main drugs used to treat Acute Myeloid Leukemia (AML), induces broad transcriptional changes in AML cells before cell death induction. The regulated genes are particularly enriched in genes controlling cell proliferation and death, as well as inflammation and immunity. These transcriptional changes are preceded by DNR-dependent deSUMOylation of chromatin proteins, which limits both the positive and negative effects of DNR on transcription. Quantitative proteomics shows that proteins that are deSUMOylated in response to DNR are mostly transcription factors, transcriptional co-regulators and chromatin organizers. Among them, the CCCTC-binding factor CTCF is highly enriched at SUMO-binding sites found in cis-regulatory regions. This is notably the case at the promoter of the DNR-induced NFKB2 gene. Its induction is preceded by a SUMO-dependent reconfiguration of chromatin loops engaging its CTCF- and SUMO-bound promoter with distal cis-regulatory regions. Altogether, our work suggests that one of the earliest effects of DNR in AML cells is a SUMO-dependent transcriptional reprogramming.
Project description:Daunorubicin (DNR) and Cytarabin (Ara-C) are the main chemotherapeutic drugs used for Acute Myeloid Leukemias (AML) treatment. However, their mode of action is not well understood. To decipher if these drug would induce rapid transcriptional reprogramming, we treated HL-60 AML cell line with DNR or Ara-C for 3 hours and carried out a transcriptomic analyses. In addition, we had shown that Reactive Oxigen Species (ROS) produced by NADPH oxidases (NOX) are involved in DNR-induced gene expression. We therefore also performed a transcriptomic analyses in HL-60 cells treated with DNR and VAS2870, an NADPH oxidase inhibitor. HL-60 cells were treated or not for 3 hours with 2 µM Ara-C, 1 µM DNR or 1 µM DNR + 20µM VAS 2870. RNAs were purified from 3 independent experiments and used to probe Affymetrix Human Gene 2.0 ST Genechips
Project description:Donminant negative transform growth factor receptor II (DNR) mice were served as a murine primary biliary cirrhrosis model. CD4+Foxp3+ Regulatory T cells (Tregs) play a critical role in self-tolerance and in regulating PBC. In order to determine whether DNR mice derived Tregs processed defective function compared with WT Tregs, CD4+Foxp3+ Treg cells were sorted from DNR and WT mice, respectively, then gene expression analysis was performed by using the Affymetrix GeneChip Mouse Genome 430 2.0 arrays
Project description:Donminant negative transform growth factor receptor II (DNR) mice were served as a murine primary biliary cirrhrosis model. CD4+Foxp3+ Regulatory T cells (Tregs) play a critical role in self-tolerance and in regulating PBC. In order to determine whether DNR mice derived Tregs processed defective function compared with WT Tregs, CD4+Foxp3+ Treg cells were sorted from DNR and WT mice, respectively, then gene expression analysis was performed by using the Affymetrix GeneChip Mouse Genome 430 2.0 arrays CD4+Foxp3+ Tregs were sorted from the spleen of 10-week-old DNR mice and B6 wild-type mice, respectively. RNA of each sample was then extracted and hybridized on Affymetrix microarrays to detail differences between DNR Tregs and WT Tregs in gene expression.
Project description:DNA microarray analysis was employed to investigate the transcriptome response to nitric oxide in Pseudomonas aeruginosa. We focused on the role played by the nitric oxide-response regulators DNR and FhpR and an oxygen-response regulator ANR in the response. The transcriptome profiles of the P. aeruginosa strains before and after exposure to nitric oxide under the microaerobic conditions were analyzed. Wild type, its anr, dnr, and fhpR mutants, and the anr mutant that express dnr were used for the analyses.
Project description:Wide inter-individual variation in terms of outcome and toxic side effects of treatment exist among patients with AML receiving chemotherapy with cytarabine (Ara-C) and daunorubicin (Dnr). Drug resistance and relapse are considered major causes of treatment failure. Gene expression profiling was undertaken to address possible mechanisms of Ara-C/Dnr resistance. Based on ex vivo Ara-C cytotoxicity at diagnosis, Ara-C sensitive (IC50 <3uM AraC) and Dnr sensitive samples (IC50 < 0.5 uM) (5 samples each) were included for microarray analysis. These were compared with the samples which were drug resistant ex vivo at diagnosis. Our microarray experiment resulted in indentifying differentially expressed genes under ex vivo Ara-C sensitive as well as Dnr sensitive samples compared to ex vivo Drug resistant samples.
Project description:Acute myeloid leukemia (AML) originates from malignant, immature myeloid progenitor cells that differentiate into dysfunctional myeloblasts. While cytarabine (Ara-C) and daunorubicin (DNR)-based chemotherapy regimens are the standard treatments, approximately 10-40% of AML patients under the age of 60 and 40-60% over 60 do not respond, leading to refractory or relapsed (R/R) AML. Targeted chemotherapy for FLT3-ITD mutated R/R AML cells improves response rates and survival outcomes in FLT3-ITD mutated R/R AML patients. However, patients with wild-type FLT3 R/R AML remain therapeutically challenged, with persistent difficulty in finding effective treatments. Better insights on the fundamental understanding of treatment failure in wild-type FLT3 AML cells are needed to enhance therapeutic outcomes. However, precise mechanisms behind the treatment failure remain unclear. This study investigates the mechanisms underlying the failure of Ara-C and DNR-based chemotherapy in wild-type FLT3 R/R AML. Using RHI-1 cells, a wild-type FLT3 AML cell line with Ara-C resistance, we demonstrated that Ara-C resistance-mediated DNR tolerance did not result from reducing the concentration of DNR in RHI-1 cells, but rather from interrupting the cytotoxic mechanisms of DNR through the Ara-C resistance of RHI-1. The down-regulated deoxycytidine kinase (DCK) in RHI-1 cells interrupted mechanisms of Ara-C cytotoxic action. Also, the down-regulation of DCK enhanced mitochondrial metabolic pathways, DNA repair process, and ROS detoxification. Through these pathways, RHI-1 cells exhibit tolerance under DNR treatment. Among these enhanced processes, targeting mitochondrial metabolism, particularly OXPHOS complex I proteins, improved the efficacy of both Ara-C and DNR. Our findings shed light on a potential mechanism underlying the treatment failure and the role of mitochondrial metabolism in wild-type FLT3 R/R AML cells.
Project description:The Acute Myeloid Leukemia cell line HL-60 was rendered resistant to daunorubicin (DNR) or cytarabine (Ara-C) by continuous exposure to the drug up to concentrations of 30nM for DNR and 100nM for Ara-C. Transcriptomic analysis were then performed by RNA-Seq to compare the cell lines