Project description:We report differential gene expression in the human AML cell line NB4 that can be partially differentiated into neutrophil granulocytes by 1µM ATRA for 2d or the vehicle DMSO only ((mock))
Project description:We report differential chromatin accessiblity in the human AML cell line NB4 that can be partially differentiated into neutrophil granulocytes by 1µM ATRA for 2d or the vehicle DMSO only ((mock))
Project description:Treatment of acute promyelocytic leukemia (APL) with all-trans-retinoic acid (ATRA) results in terminal differentiation of leukemic cells toward neutrophil granulocytes. Administration of ATRA leads to massive changes in gene expression, including down-regulation of cell proliferation-related genes and induction of genes involved in immune function. One of the most induced genes in APL NB4 cells is transglutaminase 2 (TG2). RNAi-mediated stable silencing of TG2 in NB4 cells (TG2-KD NB4) coupled with whole genome microarray analysis revealed that TG2 is involved in the expression of a large number of ATRA-regulated genes. The affected genes participate in granulocyte functions and their silencing lead to reduced adhesive, migratory and phagocytic capacity of neutrophils and less superoxide production. The expression of genes related to cell cycle control also changed, suggesting that TG2 regulates myeloid cell differentiation. CC chemokines CCL2, 3, 22, 24 and cytokines IL1B and IL8 involved in the development of differentiation syndrome (DS) are expressed at significantly lower levels in TG2-KD NB4 cells than in wild-type NB4 cells upon ATRA treatment. Based on our results, we propose that reduced expression of TG2 in differentiating APL cells may suppress effector functions of neutrophil granulocytes and attenuate the ATRA-induced inflammatory phenotype of DS. We used microarrays to detail the global program of gene expression underlying ATRA-induced differentiation of TG2 knockout NB4 cells. TG2 knockout NB4 cells were differentiated for 48 and 72 hours in the presence of ATRA and their gene expression profiles were compared to the wild-type cells at the same time points. Undifferentiated wild-type and TG2 knockout NB4 cells were used as untreated controls. Three biological replicates each.
Project description:Acute leukaemias differ from their normal haematopoietic counterparts in their inability to differentiate. This phenomenon is thought to be the result of aberrant transcriptional reprogramming involving transcription factors (TFs). Here we leveraged on Mogrify, a network-based algorithm for predicting reprogramming factors, to identify TFs and their gene regulatory networks that drive ATRA-induced differentiation of the acute promyelocytic leukaemia (APL) cell line NB4. We further integrated the detected TF regulatory networks with the Connectivity Map (CMAP) repository and recovered small molecule compounds which induce similar transcriptional changes. Our method outperformed standard approaches, retrieving ATRA as the top hit. Of the other drug hits, dimaprit and mebendazole enhanced ATRA-mediated differentiation in both parental NB4 and ATRA-resistant NB4-MR2 cells. Thus, we provide a proof-of-principle of our network-based computational platform for drug discovery and repositioning in leukaemia differentiation therapy, which can be extended to other dysregulated disease states.
Project description:HOTAIRM1 is a long intergenic non-coding RNA located in the human HOXA gene cluster, with gene expression highly specific for maturing myeloid cells, particularly during all-trans retinoic acid (ATRA) induction of granolopoiesis in NB4, a human t(15;17) acute promyelocytic leukemia (APL) cell line. We sought to assess the impact of HOTAIR knockdown on the global programme of gene expression underlying the granulocytic maturing process in NB4 cells. The knockdown of HOTAIRM1 resulted in a less differentiated expression profile in the NB4 cells after 4 days of ATRA-induced granulocytic differentiation, with retained expression of many otherwise ATRA-suppressed cell cycle and DNA replication genes, as well as abated induction of cell surface leukocyte activation and defense response genes.
Project description:HOTAIRM1 is a long intergenic non-coding RNA located in the human HOXA gene cluster, with gene expression highly specific for maturing myeloid cells, particularly during all-trans retinoic acid (ATRA) induction of granolopoiesis in NB4, a human t(15;17) acute promyelocytic leukemia (APL) cell line. We sought to assess the impact of HOTAIR knockdown on the global programme of gene expression underlying the granulocytic maturing process in NB4 cells. The knockdown of HOTAIRM1 resulted in a less differentiated expression profile in the NB4 cells after 4 days of ATRA-induced granulocytic differentiation, with retained expression of many otherwise ATRA-suppressed cell cycle and DNA replication genes, as well as abated induction of cell surface leukocyte activation and defense response genes. The shRNA expressing vector targeting the HOTAIRM1 transcript and the control vector expressing scrambled shRNA sequence were generated based on the pLKO.3G vector backbone (Addgene). The stable cell lines derived from NB4 cells transfected with lentiviral vectors were selected by FACS sorting of GFP selection marker positive cells and isolation of single cell derived clones on soft agar plates. Biologically duplicated total RNA samples were prepared from HOTAIRM1 knockdown and the scrambled shRNA expressing control cells, plus one total RNA from each of wild type NB4 cells and HOTAIRM1 knockdown (by a different shRNA construct) cells, before and after 96 hours of ATRA (0.5 uM) induced granulocytic differentiation.
Project description:NB4 is an APL derived cell line, carrying the t(15;17) translocation and expressing the PML/RARa fusion protein. Still, an important question that remains to be addressed is whether PML/RARa target genes are transcriptionally suppressed in primary APL cells and re-activated in all-trans retinoic acid (ATRA) treated NB4 cells. Gene expression of NB4 cells treated with ATRA at different time points were analyzed.
Project description:NB4 is an APL derived cell line, carrying the t(15;17) translocation and expressing the PML/RARa fusion protein. Still, an important question that remains to be addressed is whether PML/RARa target genes are transcriptionally suppressed in primary APL cells and re-activated in all-trans retinoic acid (ATRA) treated NB4 cells. Gene expression of NB4 cells treated with ATRA at different time points were analyzed. Experiment Overall Design: 6 samples at various times. No replicats.
Project description:Acute promyelocytic leukemia (APL) is a hematological disease characterized by a balanced reciprocal translocation that leads to the synthesis of the oncogenic fusion protein PML-RARα. APL is mainly managed by a differentiation therapy based on the administration of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). However, therapy resistance, differentiation syndrome, and relapses require the development of new low-toxicity therapies based on the induction of blasts differentiation. Here, we performed a high-throughput gene expression profile of the maturation inducible APL cell line NB4 untreated or exposed to ATRA.
Project description:Treatment of acute promyelocytic leukemia (APL) with all-trans-retinoic acid (ATRA) results in terminal differentiation of leukemic cells toward neutrophil granulocytes. Administration of ATRA leads to massive changes in gene expression, including down-regulation of cell proliferation-related genes and induction of genes involved in immune function. One of the most induced genes in APL NB4 cells is transglutaminase 2 (TG2). RNAi-mediated stable silencing of TG2 in NB4 cells (TG2-KD NB4) coupled with whole genome microarray analysis revealed that TG2 is involved in the expression of a large number of ATRA-regulated genes. The affected genes participate in granulocyte functions and their silencing lead to reduced adhesive, migratory and phagocytic capacity of neutrophils and less superoxide production. The expression of genes related to cell cycle control also changed, suggesting that TG2 regulates myeloid cell differentiation. CC chemokines CCL2, 3, 22, 24 and cytokines IL1B and IL8 involved in the development of differentiation syndrome (DS) are expressed at significantly lower levels in TG2-KD NB4 cells than in wild-type NB4 cells upon ATRA treatment. Based on our results, we propose that reduced expression of TG2 in differentiating APL cells may suppress effector functions of neutrophil granulocytes and attenuate the ATRA-induced inflammatory phenotype of DS.