HDAC7 induction combined with standard-of-care chemotherapy provides a therapeutic advantage in t(4 11) infant B-ALL
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PROVIDER: PRJNA1117828 | ENA |
REPOSITORIES: ENA
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Project description:Infants diagnosed with acute lymphoblastic leukemia (B-ALL) and t(4;11) chromosomal rearrangements represent a subset of patients with poor therapeutic response. t(4;11) B-ALL cells exhibit low levels of HDAC7, which is essential for optimal B lymphocyte differentiation. Here, we show that HDAC7 silencing in this malignancy is mediated by epigenetic mechanisms involving the chromatin remodeler EZH2 and the KMT2A-AFF1 fusion protein. Remarkably, the menin inhibitor MI-538 restores HDAC7 expression, and this effect is enhanced by the addition of the class I HDAC inhibitor chidamide. This treatment drives leukemic pro-B cells towards a more differentiated and less malignant state, thereby impairing aberrant proliferation. In addition to reducing the malignant capacity of leukemic cells in vitro, addition of MI-538 and chidamide to standard chemotherapy shows promise in reducing the engraftment of t(4;11) pro-B-ALL cells in vivo and delaying relapse. Finally, the newly developed therapy increases the ex vivo glucocorticoid sensitivity of t(4;11) pro-B-ALL primary cells.
2025-08-06 | GSE268574 | GEO
Project description:Infants diagnosed of precursor B-cell acute lymphoblastic leukemia (iB-ALL) presenting MLL-AF4 chromosomal rearrangement are at high risk of disease progression into fatal outcome. This specific subtype of pediatric leukemia constitutes a tough challenge in leukemia research, given the difficulties found when trying in vivo modelling. However, the understanding of mechanisms leading to proper lymphocyte generation may become of high utility in gaining deep insight on this malignancy. As we report here, the lack of HDAC7, a key transcriptional regulator in B lymphocyte differentiation, worsens the prognosis of iB-ALL patients. In fact, MLL-AF4+ iB-ALL patients with high expression of HDAC7 display an improved survival, partially mediated by the repression of oncogenes, such as c-MYC, and chemoresistance markers, like the ASNS enzyme. Accordingly, HDAC7 drastically reduces leukemic cells proliferation in MLL-AF4+ iB-ALL through the induction of apoptosis. Moreover, RNA sequencing of HDAC7-overexpressing cells has revealed that HDAC7 alters the genomic profiling of MLL-AF4+ iB-ALL cells towards that of healthy B-cell progenitors. In summary, the findings here reported highlight the role of HDAC7 in predicting prognosis of a lethal subtype of iB-ALL and open new clinical perspectives, since MLL-AF4+ iB-ALL infants would highly benefit from therapeutic options eventually restoring HDAC7 expression.
2021-06-04 | GSE151793 | GEO
Project description:Title of Publication: Histone Deacetylase 7 Regulates Cell Survival and TCR Signaling in CD4/CD8 Double-Positive Thymocytes Abstract of publicaton: CD4/CD8 double-positive (DP) thymocytes express the transcriptional repressor Histone Deacetylase 7 (HDAC7), a class IIa HDAC that is exported from the cell nucleus after T cell receptor (TCR) engagement. Through signal-dependent nuclear export, class IIa HDACs such as HDAC7 mediate signal-dependent changes in gene expression that are important to developmental fate decisions in multiple tissues. We report that HDAC7 is exported from the cell nucleus during positive selection in thymocytes, and regulates genes mediating the coupling between TCR engagement and downstream events that determine cell survival. Thymocytes lacking HDAC7 are inefficiently positively selected due to a severely shortened lifespan and exhibit a truncated repertoire of TCR J segments. The expression of multiple important mediators and modulators of the response to TCR engagement is altered in HDAC7-deficient thymocytes, resulting in increased tonic MAP kinase activity that contributes to the observed loss of viability. Remarkably, the activity of Protein Kinase D, the kinase that mediates nuclear export of HDAC7 in response to TCR signaling, is also increased in HDAC7-deficient thymocytes, suggesting that HDAC7 nuclear export governs a self-sustaining auto-excitatory loop. These experiments add to the understanding of the life/death decision in thymic T cell development, define a novel function for class IIa HDACs, and point to a novel feed-forward mechanism whereby these molecules regulate their own state and mediate stable developmental transitions. Goal of Microarray experiment: We did these experiments to determine how alteration of the function of HDAC7, a site-specific and signal-dependent repressor of transcription, changes gene expression in CD4/CD8 DP thymocytes. Three biological replicate samples were prepared for each non-wild type mouse strain (Samples 7-18). Six biological replicates were prepared for the wild type strain (Samples 1-6). Total RNA was prepared from isolated CD4/CD8 Double-positive thymocytes and labeled with the Affymetrix Whole-Transcript labeling protocol. Labeled probes were hybridized to one Affymetrix Mouse Gene 1.0ST array each. Data from .cel files were normalized using RMA, in normalization groups representing each of the binary comparisons made. These binary comparisons between sample groups represent gene expression changes due to loss of HDAC7 (samples 1-3 vs. 7-9), transgenic expression of an HDAC7-VP16 fusion protein (samples 4-6 vs. 10-12), positive thymic selection (samples 1-6 vs. samples 11-15), and negative thymic selection (Samples 11-15 vs. samples 16-18).
2011-04-06 | E-GEOD-26488 | biostudies-arrayexpress
Project description:Overexpression HDAC7 can enhance iPS efficiency in SKO by supressing MEF2 factors We used microarrays to identify changes induced by overexpression of HDAC7 or MEF2C. MEFs were transduced with SKO plus HDAC7 or MEF2C compared to SKO plus empty vector(Flag), GFP as controls. TRIZOL cell lysates were prepared from D6 and D10.
2011-08-17 | E-GEOD-23692 | biostudies-arrayexpress
Project description:Histone deacetylase 7 (HDAC7) is highly expressed in CD4+/CD8+ thymocytes and functions as a signal-dependent repressor of gene transcription during T cell development. In this study, we express HDAC7 mutant proteins in a T cell line and use DNA microarrays to identify transcriptional targets of HDAC7 in T cells. Gene expression changes are compared to differential gene expression profiles associated with positive and negative thymic selection. This analysis reveals that HDAC7 regulates an extensive set of genes that are differentially expressed during both positive and negative thymic selection. Many of these genes play important functional roles in positive and negative selection, primarily via coupling between antigen receptor and downstream signaling events. Keywords: microarray gene expression profiling, comparison of perturbation of HDAC7 gene function with differential expression during thymic selection
2007-11-04 | GSE7468 | GEO
Project description:The present study reports an unbiased analysis of the cytotoxic T cell serine-threonine phosphoproteome using high resolution mass spectrometry. Approximately 2,000 phosphorylations were identified in CTLs of which approximately 450 were controlled by TCR signaling. A significantly overrepresented group of molecules identified in the phosphoproteomic screen were transcription activators, co-repressors and chromatin regulators. A focus on the chromatin regulators revealed that CTLs have high expression of the histone deacetylase HDAC7 but continually phosphorylate and export this transcriptional repressor from the nucleus. HDAC7 dephosphorylation results in its nuclear accumulation and suppressed expression of genes encoding key cytokines, cytokine receptors and adhesion molecules that determine CTL function. The screening of the CTL phosphoproteome thus reveals intrinsic pathways of serine-threonine phosphorylation that target chromatin regulators in CTLs and determine the CTL functional program. We used Affymetrix microarray analysis to explore the molecular basis for the role of HDAC7 in CTLs and the impact of GFP-HDAC7 phosphorylation deficient mutant expression on the CTL transcriptional profile. In vitro generated P14 TCR cytotoxic T cells were retrovirally infected with a construct encoding GFP-HDAC7 phosphorylation deficient mutant, sorted in base of GFP expression (GFP positive and GFP negative) and processed for microarray analysis in three biological replicas.
2011-03-13 | E-GEOD-27092 | biostudies-arrayexpress
Project description:Abstract of publicaton: CD4/CD8 double-positive (DP) thymocytes express the transcriptional repressor Histone Deacetylase 7 (HDAC7), a class IIa HDAC that is exported from the cell nucleus after T cell receptor (TCR) engagement. Through signal-dependent nuclear export, class IIa HDACs such as HDAC7 mediate signal-dependent changes in gene expression that are important to developmental fate decisions in multiple tissues. We report that HDAC7 is exported from the cell nucleus during positive selection in thymocytes, and regulates genes mediating the coupling between TCR engagement and downstream events that determine cell survival. Thymocytes lacking HDAC7 are inefficiently positively selected due to a severely shortened lifespan and exhibit a truncated repertoire of TCR Jalpha segments. The expression of multiple important mediators and modulators of the response to TCR engagement is altered in HDAC7-deficient thymocytes, resulting in increased tonic MAP kinase activity that contributes to the observed loss of viability. Remarkably, the activity of Protein Kinase D, the kinase that mediates nuclear export of HDAC7 in response to TCR signaling, is also increased in HDAC7-deficient thymocytes, suggesting that HDAC7 nuclear export governs a self-sustaining auto-excitatory loop. These experiments add to the understanding of the life/death decision in thymic T cell development, define a novel function for class IIa HDACs, and point to a novel feed-forward mechanism whereby these molecules regulate their own state and mediate stable developmental transitions. Title of manuscript: Nuclear Export of Histone Deacetylase 7 During Thymic Selection Mediates Immune Self-tolerance. abstract of manuscript: Histone Deacetylase 7 (HDAC7) is a TCR signal-dependent regulator of differentiation that is highly expressed in CD4/CD8 double-positive (DP) thymocytes. Here we examine the effect of blocking TCR-dependent nuclear export of HDAC7 during thymic selection, through expression of a signal-resistant mutant of HDAC7 (HDAC7-?P) in thymocytes. We find that HDAC7-?P Transgenic thymocytes exhibit a profound block in negative thymic selection, but can still undergo positive selection, resulting in the escape of autoreactive T cells into the periphery. Gene expression profiling reveals a comprehensive suppression of the negative selection-associated gene expression program in DP thymocytes, associated with a defect in the activation of MAP kinase pathways by TCR signals. The consequence of this block in vivo is a lethal autoimmune syndrome involving the exocrine pancreas and other abdominal organs. These experiments establish a novel molecular model of autoimmunity and cast new light on the relationship between thymic selection and immune self-tolerance. Goal of Microarray experiment: We did these experiments to determine how alteration of the function of HDAC7, a site-specific and signal-dependent repressor of transcription, changes gene expression in CD4/CD8 DP thymocytes.
2011-04-06 | GSE26488 | GEO
Project description:Correct B cell identity at each stage of cellular differentiation during B lymphocyte development is critically dependent on a tightly controlled epigenomic landscape. We previously identified HDAC7 as an essential regulator of early B cell development and its absence leads to a drastic block at the pro-B to pre-B cell transition. More recently, we demonstrated that HDAC7 loss in pro-B-ALL in infants associates with a worse prognosis. Here we delineate the molecular mechanisms by which HDAC7 modulates early B cell development. We find that HDAC7 deficiency drives global chromatin de-condensation, histone marks deposition and deregulates other epigenetic regulators and mobile elements. Specifically, the absence of HDAC7 induces TET2 expression, which promotes DNA 5-hydroxymethylation and chromatin de-condensation. HDAC7 deficiency also results in the aberrant expression of microRNAs and LINE-1 transposable elements. These findings shed light on the mechanisms by which HDAC7 loss or misregulation may lead to B cell–based hematological malignancies.
2022-06-27 | GSE171855 | GEO
Project description:Overexpression HDAC7 can enhance iPS efficiency in SKO by supressing MEF2 factors We used microarrays to identify changes induced by overexpression of HDAC7 or MEF2C.
2011-08-18 | GSE23692 | GEO
Project description:The establishment of proper epigenomic landscape is essential during B lymphocyte development in order to acquire a correct B cell identity at each cellular differentiation stage. We previously identified HDAC7 as a critical regulator of early B cell development. Its absence indeed led to the aberrant activation of inappropriate lineage genes, a reduction of proliferation and an increase in cell apoptosis. More recently, we have demonstrated that HDAC7 loss in infant pro-B-ALL associates with poor prognosis. Here we shed light into the HDAC7-mediated molecular mechanisms during early B cell development. HDAC7 deficiency drives not only the expression of inappropriate lineage genes, but also global chromatin de-condensation and deregulation of epigenetic regulators of DNA methylation and potential damaging elements. Specifically, HDAC7 absence induces the expression of TET2, which promotes DNA 5-hydroxymethylation and aberrant gene activation. HDAC7 deficiency also results in the uncontrolled expression of microRNAs and non-coding elements such as LINE-1 transposable elements. These findings are relevant for the mechanistic explanation of why HDAC7 is affected in multiple B-related hematological malignancies. Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) for histone modifications H3K27ac and H3K27me3 in murine pro-B lymphocytes.
2022-06-27 | GSE204673 | GEO