Project description:BCR-ABL positive acute lymphoblastic leukemia (ALL) cell survival is strongly dependent on the IRE1α-XBP1 branch of the Unfolded Protein Response (UPR). In the study at hand, we have focused on exploring the link between BCR-ABL1 and IRE1α to better understand whether a simultaneous pharmacological inhibition of both pathways could represent a beneficial therapeutic strategy in Philadelphia positive (Ph+) ALL. Therefore, the effect on the phosphoproteome of two inhibitors (MKC-8866 and Nilotinib) as well as a combination of both compounds was analysed in this study.
Project description:Acute lymphoblastic leukemia (ALL) is associated with significant morbidity and mortality necessitating further improvements in diagnosis and therapy. Targeted therapies directed against epigenetic regulators, which are frequently mutated or misregulated in acute leukemia, are emerging as candidate approaches in preclinical studies and early trials. However, the epigenetic factors involved in most ALLs are not well defined or functionally characterized. In this study, we demonstrate an oncogenic role for the protein lysine methyltransferase SETDB2 in leukemia pathogenesis. It is over-expressed in a wide spectrum of leukemias, required for their maintenance in vitro and in vivo, and its elevated expression correlates with a poor prognosis in clinical cohorts. In a subset of ALL with the preBCR+ phenotype, SETDB2 expression is maintained as a direct target gene of the chimeric transcription factor E2A-PBX1. In this subset, SETDB2 epigenetically suppresses expression of the cell cycle inhibitor CDKN2C through histone H3K9 tri-methylation thus establishing a novel oncogenic pathway subordinate to E2A-PBX1 that silences a major tumor suppressor in ALL. In contrast, SETDB2 was relatively dispensable for normal hematopoietic stem and progenitor cell proliferation. In addition to targeting SETDB2 alone, its knockdown significantly enhanced sensitivity to kinase and epigenetic inhibitors suggesting a potential approach to future combination treatments. Our studies define an epigenetic role for SETDB2 in leukemia pathogenesis, and provide a mechanistic rationale for targeting SETDB2 therapeutically in a subset of leukemia.
Project description:Taking the advantage of the human bone marrow (BM) scRNA-seq in Human cell atlas census of immune cells study, we resolved B lineage into comprehensive human B-cell development stages and identified their landscape in B-ALL. L-asparaginase is the cornerstone of combination protocols in acute lymphoblastic leukemia (ALL). After profiled B cell acute lymphoblastic leukemia (B-ALL) patient drug sensitivities ex vivo and applied network-based systems pharmacology analyses to examine signal circuitry, we revealed that the B-cell differentiation are correlated with the L-asparaginase response in B-ALL. Further multiomics analysis confirmed that L-asparaginase resistant B-ALL had higher percentage of Pre-pro-B like cells and less Pro-B like cells. By targeting BCL2, the key hub genes in Pre-pro-B cell network, Venetoclax combined with L-asparaginase can produce better outcome as demonstrated by in vitro and in vivo evaluations. In conclusion, our results identified B-ALL heterogeneity in L-asparaginase-resistant signature and BCL2 signaling and B-cell maturation stage, consistent with L-asparaginase response, providing unique opportunities for total clonal therapy.
Project description:This SuperSeries is composed of the following subset Series: GSE4070: Clinical acute lymphoblastic leukemia samples (untreated) with known asparaginase LC50 values GSE4071: Clinical pediatric acute lymphoblastic leukemia samples after in vitro exposure to L-asparaginase GSE4072: L-asparaginase exposure in acute lymphoblastic leukemia cell lines time series Abstract: To investigate the effect of l-asparaginase on acute lymphoblastic leukemia (ALL), we used cDNA microarrays to obtain a genome-wide view of gene expression both at baseline and after in vitro exposure to l-asparaginase in cell lines and pediatric ALL samples. In 16 cell lines, a baseline gene expression pattern distinguished l-asparaginase sensitivity from resistance. However, for 28 pediatric ALL samples, no consistent baseline expression pattern was associated with sensitivity to l-asparaginase. In particular, baseline expression of asparagine synthetase (ASNS) was not predictive of response to l-asparaginase. After exposure to l-asparaginase, 5 cell lines and 10 clinical samples exhibited very similar changes in the expression of a large number of genes. However, the gene expression changes occurred more slowly in the clinical samples. These changes included a consistent increase in expression of tRNA synthetases and solute transporters and activating transcription factor and CCAAT/enhancer binding protein family members, a response similar to that observed with amino acid starvation. There was also a consistent decrease in many genes associated with proliferation. Taken together, the changes seem to reflect a consistent coordinated response to asparagine starvation in both cell lines and clinical samples. Importantly, in the clinical samples, increased expression of ASNS after l-asparaginase exposure was not associated with in vitro resistance to l-asparaginase, indicating that ASNS-independent mechanisms of in vitro l-asparaginase resistance are common in ALL. These results suggest that targeting particular genes involved in the response to amino acid starvation in ALL cells may provide a novel way to overcome l-asparaginase resistance. Refer to individual Series
Project description:Genetic studies in T-cell acute lymphoblastic leukemia have uncovered a remarkable complexity of oncogenic and loss-of-function mutations. Amongst this plethora of genetic changes, NOTCH1 activating mutations stand out as the most frequently occurring genetic defect, identified in more than 50% of T-cell acute lymphoblastic leukemias, supporting an essential driver role for this gene in T-cell acute lymphoblastic leukemia oncogenesis. In this study, we aimed to establish a comprehensive compendium of the long non-coding RNA transcriptome under control of Notch signaling. For this purpose, we measured the transcriptional response of all protein coding genes and long non-coding RNAs upon pharmacological Notch inhibition in the human T-cell acute lymphoblastic leukemia cell line CUTLL1 using RNA-sequencing. Similar Notch dependent profiles were established for normal human CD34+ thymic T-cell progenitors exposed to Notch signaling activity in vivo. In addition, we generated long non-coding RNA expression profiles (array data) from GSI treated T-ALL cell lines, ex vivo isolated Notch active CD34+ and Notch inactive CD4+CD8+ thymocytes and from a primary cohort of 15 T-cell acute lymphoblastic leukemia patients with known NOTCH1 mutation status. Integration of these expression datasets with publically available Notch1 ChIP-sequencing data resulted in the identification of long non-coding RNAs directly regulated by Notch activity in normal and malignant T-cell context. Given the central role of Notch in T-cell acute lymphoblastic leukemia oncogenesis, these data pave the way towards development of novel therapeutic strategies that target hyperactive Notch1 signaling in human T-cell acute lymphoblastic leukemia. CD34+ cells of 2 healthy donors are cultured on a OP9-GFP or OP9-DLL1 feeder layer.
Project description:Genetic studies in T-cell acute lymphoblastic leukemia have uncovered a remarkable complexity of oncogenic and loss-of-function mutations. Amongst this plethora of genetic changes, NOTCH1 activating mutations stand out as the most frequently occurring genetic defect, identified in more than 50% of T-cell acute lymphoblastic leukemias, supporting an essential driver role for this gene in T-cell acute lymphoblastic leukemia oncogenesis. In this study, we aimed to establish a comprehensive compendium of the long non-coding RNA transcriptome under control of Notch signaling. For this purpose, we measured the transcriptional response of all protein coding genes and long non-coding RNAs upon pharmacological Notch inhibition in the human T-cell acute lymphoblastic leukemia cell line CUTLL1 using RNA-sequencing. Similar Notch dependent profiles were established for normal human CD34+ thymic T-cell progenitors exposed to Notch signaling activity in vivo. In addition, we generated long non-coding RNA expression profiles (array data) from GSI treated T-ALL cell lines, ex vivo isolated Notch active CD34+ and Notch inactive CD4+CD8+ thymocytes and from a primary cohort of 15 T-cell acute lymphoblastic leukemia patients with known NOTCH1 mutation status. Integration of these expression datasets with publically available Notch1 ChIP-sequencing data resulted in the identification of long non-coding RNAs directly regulated by Notch activity in normal and malignant T-cell context. Given the central role of Notch in T-cell acute lymphoblastic leukemia oncogenesis, these data pave the way towards development of novel therapeutic strategies that target hyperactive Notch1 signaling in human T-cell acute lymphoblastic leukemia. CD34+ cells of 4 healthy donors are cultured on a OP9-GFP or OP9-DLL1 feeder layer.
Project description:Genetic studies in T-cell acute lymphoblastic leukemia have uncovered a remarkable complexity of oncogenic and loss-of-function mutations. Amongst this plethora of genetic changes, NOTCH1 activating mutations stand out as the most frequently occurring genetic defect, identified in more than 50% of T-cell acute lymphoblastic leukemias, supporting an essential driver role for this gene in T-cell acute lymphoblastic leukemia oncogenesis. In this study, we aimed to establish a comprehensive compendium of the long non-coding RNA transcriptome under control of Notch signaling. For this purpose, we measured the transcriptional response of all protein coding genes and long non-coding RNAs upon pharmacological Notch inhibition in the human T-cell acute lymphoblastic leukemia cell line CUTLL1 using RNA-sequencing. Similar Notch dependent profiles were established for normal human CD34+ thymic T-cell progenitors exposed to Notch signaling activity in vivo. In addition, we generated long non-coding RNA expression profiles (array data) from GSI treated T-ALL cell lines, ex vivo isolated Notch active CD34+ and Notch inactive CD4+CD8+ thymocytes and from a primary cohort of 15 T-cell acute lymphoblastic leukemia patients with known NOTCH1 mutation status. Integration of these expression datasets with publically available Notch1 ChIP-sequencing data resulted in the identification of long non-coding RNAs directly regulated by Notch activity in normal and malignant T-cell context. Given the central role of Notch in T-cell acute lymphoblastic leukemia oncogenesis, these data pave the way towards development of novel therapeutic strategies that target hyperactive Notch1 signaling in human T-cell acute lymphoblastic leukemia. Gene expression was measured in sorted T-cell subsets of 4 healthy donors.