Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

BCL6 mediates Chemoresistance in Acute Myeloid Leukemia

ABSTRACT: BCL6 is a transcription repressor that plays a crucial role in germinal center formation and lymphomagenesis. However, its role in myeloid malignancies remains unclear. Here, we explored the role of BCL6 in acute myeloid leukemia (AML). Heterogeneous levels of BCL6 were found across AML cell lines and primary AML samples. Cells with higher levels of BCL6 were indeed sensitive to treatment with BCL6 inhibitors. Gene expression profiling of AML cells treated with BCL6 inhibitor revealed a subset of target genes that are common with lymphoma cells. Ex vivo treatment of primary AML cells with BCL6 peptide inhibitor (BPI) induced apoptosis and decrease colony forming capacity which correlated with the levels of BCL6 expression . Importantly, inhibition of BCL6 in primary AML cells with either BPI or BCL6 siRNA resulted in significant reduction of leukemia initiating capacity using immunodeficient mice, suggesting ablation of leukemia stem cells (LSC). Such anti-LSC activity was also observed as downregulation of LSC gene signatures using gene expression analyses of cells treated with a BCL6 inhibitor. Importantly, treatment with cytarabine (AraC) induced BCL6 expression, and the levels of BCL6 induction were correlated with resistance to AraC. Treatment of AML primary derived xenografts (PDX) revealed that when AraC was combined with BCL6 inhibitor, inhibition of BCL6 significantly potentiated the efficacy of AraC and improved cytotoxic effects by interfering with the leukemia initiating capacity of AML cells. This suggests that pharmacological inhibition of BCL6 might provide a novel therapeutic strategy for ablation of LSCs and overcome chemoresistance in AML.

ORGANISM(S): Homo sapiens

PROVIDER: GSE133112 | GEO | 2020/08/01

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

miR-126 governs human leukemia stem cell quiescence and therapeutic resistance

Project description:In acute myeloid leukemia (AML), leukemia stem cells (LSC) play a central role in disease progression and recurrence due to their intrinsic capacity for self-renewal and chemotherapy resistance. Whereas epigenetic regulation balances normal blood stem cell self-renewal and fate decisions, mutation and dysregulation of epigenetic modifiers are now considered fundamental to leukemia initiation and progression. Alterations in miRNA function represent a non-canonical epigenetic mechanism influencing malignant hematopoiesis, however the function of miRNA in LSC remains undetermined. Here we show that miRNA profiling of fractionated AML populations defines an LSC-specific signature that is highly predictive of patient survival. Gain of function genetic analysis demonstrated that miR-126 restrained cell cycle progression, prevented LSC differentiation, and increased LSC self-renewal. miR-126 promoted chemo-resistance, preserving LSC quiescence in part through suppression of the G0 to G1 gatekeeper, CDK3. Thus, in AML, miRNAs influence patient outcome through post-transcriptional regulation of stemness programs in LSC. 74 primary patient normal karyotype AML samples were analyzed for miRNA expression.

2016-02-01 | E-GEOD-55770 | biostudies-arrayexpress

BCL6 repression of EP300 provides a basis for rational combinatorial therapy in diffuse large B cell lymphomas.

Project description:The BCL6 transcriptional repressor is a critical oncogene in diffuse large B-cell lymphomas (DLBCL). The specific BCL6 inhibitor RI-BPI potently kills DLBCL cells. We find that RI-BPI induces a particular gene expression signature in DLBCL. In order to identify classes of drugs that might synergize with RIBPI we examined the connectivity of this signature and found a strong association with HDAC and Hsp90 inhibitors. This was explained by the discovery that BCL6 directly represses the p300 lysine acetyltransferase and its co-factor BAT3. RI-BPI induced expression of p300 and BAT3, and p300 acetyltransferase activity, resulting in acetylation of p300 targets like p53 and Hsp90. As a consequence, RI-BPI could attenuate Hsp90 chaperone function, similar to the effect of Hsp90 and HDAC inhibitors. Induction of p300 and BAT3 was required for the anti-lymphoma effects of RI-BPI since specific blockade of either protein rescued DLBCL cells from the BCL6 inhibitor. RI-BPI synergistically killed DLBCL cells in combination with HDAC inhibitors (SAHA, TSA and VPA) and Hsp90 inhibitors (17-DMAG and PUH71). The combination of RI-BPI and SAHA, or RI-BPI and PU-H71 potently suppressed or even eradicated human DLBCL in mice. BCL6 repression of EP300 thus provides a basis for rational targeted combinatorial therapy for patients with DLBCL. Direct comparison of gene expression levels in DLBCL cell lines after 24hs of treatment with either a Bcl6 inhibitor peptide or control peptide

2010-09-21 | E-GEOD-24236 | biostudies-arrayexpress

miR-126 Governs Human Leukemia Stem Cell Quiescence and Therapeutic Resistance

Project description:In acute myeloid leukemia (AML), leukemia stem cells (LSC) play a central role in disease progression and recurrence due to their intrinsic capacity for self-renewal and chemotherapy resistance. Whereas epigenetic mechanisms balance normal blood stem cell self-renewal and fate decisions, mutation and dysregulation of epigenetic regulators are considered fundamental to leukemia initiation and progression. Alterations in miRNA function represent a non-canonical epigenetic mechanism influencing malignant hematopoiesis, however the function of miRNA in human LSC remains undetermined. Here we show that miRNA profiling of fractionated AML populations defines an LSC-specific signature that is highly prognostic for patient survival. Gain- and loss-of-function analyses demonstrated that miR-126 restrained cell cycle progression, prevented differentiation, and increased self-renewal of human LSC. By targeting the G0 to G1 gatekeeper CDK3, miR-126 preserved LSC quiescence and promoted chemotherapy resistance. Thus, in AML, miRNAs influence patient outcome through post-transcriptional regulation of stemness programs in LSC.

2016-03-31 | PXD001994 | Pride

Inhibition of Bcl6-SMRT/NCoR interactions by an inhibitory peptide affects inflammatory pathways

Project description:Using microarrays, we compared the changes in levels of gene expression between wild type mouse bone marrow derived macrophages upon treatment with the Bcl6 peptide inhibitor, RI-BPI, that specifically blocks interaction between BCL6 and the co-repressors NCoR or SMRT. Total RNA was obtained from cultered wild type primary bone marrow-derived macrophages that were treated with either 5 μM control or RI-BPI peptide in MSF media for 12 hours.

2012-03-29 | E-GEOD-27001 | biostudies-arrayexpress

BCL6 repression of EP300 provides a basis for rational combinatorial therapy in diffuse large B cell lymphomas.

2010-09-21 | GSE24236 | GEO

Gene expression data of BCR-ABL1 transformed myeloid cells from BCL6 wild-type and BCL6 knockout mice treated with and without Imatinib and RI-BPI

Project description:To identify differences in the gene regulation between BCL6+/+ and BCL6-/- CML cells a gene expression analysis has been performed. We investigated the gene expression pattern in BCL6+/+ cells in the presence or absence of Imatinib and a combination of Imatinib and RI-BPI (a novel retro-inverso BCL6 peptide inhibitor). In BCL6-/- CML cells, we investigated the gene expression pattern in the presence or absence of Imatinib. BCR-ABL1 transformed myeloid cells from BCL6+/+ mice were cultured in the presence or absence of 10µM Imatinib or 10µM Imatinib and 20µM RI-BPI for 16 hours. BCR-ABL1 transformed myeloid cells from BCL6-/- mice were cultured in the presence or absence of 10µM Imatinib. Two samples for each condition were processed.

2011-08-23 | E-GEOD-24813 | biostudies-arrayexpress

Acute myeloid leukemia cells resist chemotherapy through a transient senescence-like state [scRNA-seq]

Project description:In acute myeloid leukemias (AML), chemotherapy is frequently followed by disease relapse, yet the mechanism by which AML reemerges is not fully understood. We hypothesized that chemotherapy induces senescence-like dormancy that facilitates survival to genotoxic exposure, allowing AML cells to endure treatment in a transiently dormant state while retaining potential for leukemic repopulation. Here, we show that primary AML cells exhibit hallmark senescence features following treatment with cytarabine (AraC), including growth arrest, increased cellular granularity, senescence-associated-β-galactosidase (SA-β-gal) activity, and senescence-associated transcriptomic alterations. Induction of AraC-induced premature senescence was regulated by the ATR kinase activity and mediated stress-survival. High-throughput single cell RNA (scRNA)-seq analysis of primary AML cells ex vivo and in vivo following chemotherapy suggest active transcriptional programming towards senescent-like dormancy instead of enrichment for leukemia stem cells (LSCs). scRNA-seq of sorted AraC-induced premature senescent AML cells demonstrated a heterogenous population including a fraction of cells with simultaneous expression of dormancy- and senescence-associated gene signatures. Xenotransplantation of AraC-induced premature senescent AML cells into mice demonstrated that senescent-like AML cells maintain leukemia-repopulating potential. Altogether, we propose a mechanism of AML relapse whereby AML cells tolerate chemotherapy via acquisition of a transient senescent-like state.

2021-03-14 | GSE146590 | GEO

Acute myeloid leukemia cells resist chemotherapy through a transient senescence-like state [Array]

2021-03-14 | GSE146542 | GEO

Acute myeloid leukemia cells resist chemotherapy through a transient senescence-like state [RNA-seq]

2021-03-14 | GSE145061 | GEO

Acute myeloid leukemia cells resist chemotherapy through a transient senescence-like state [PDX]

2021-03-14 | GSE146592 | GEO