HOX
 gene expression in phenotypic and genotypic subgroups and low HOXA
 gene expression as an adverse prognostic factor in pediatric ALL

ABSTRACTNucleoporins regulate nuclear transport. In addition, nucleoporins also modulate chromatin organization and gene expression. Here we investigated the role of nucleoporin Nup93, in regulating HOXA gene expression during differentiation. ChIP-Seq analysis revealed that Nup93 associates with genes involved in development and differentiation. Furthermore, Nup93 occupancy significantly overlaps with CTCF. Interestingly, Nup93 and CTCF show antagonistic roles in regulating 3’ and 5’ end HOXA genes in undifferentiated cells. The HOXA gene locus untethered from the nuclear periphery upon Nup93 but not CTCF depletion, consistent with its upregulation. Remarkably, occupancy of Nup93 and CTCF on HOXA gene locus progressively declined during differentiation but was restored in differentiated cells, consistent with the rerepression and re-localization of the HOXA gene locus with the nuclear periphery upon differentiation. In summary, Nup93 is a key modulator of the spatiotemporal dynamics and function of the HOXA gene locus during differentiation.

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ASXL1 Mutations Promote Myeloid Transformation Through Inhibition of PRC2-Mediated Gene Repression

Blood ◽

10.1182/blood.v118.21.405.405 ◽

2011 ◽

Vol 118 (21) ◽

pp. 405-405 ◽

Cited By ~ 2

Author(s):

Omar Abdel-Wahab ◽

Mazhar Adli ◽

Lindsay Saunders ◽

Jie Gao ◽

Alan H. Shih ◽

...

Keyword(s):

Gene Expression ◽

Research Funding ◽

Hematopoietic Cells ◽

Loss Of Function ◽

Genome Wide ◽

Hoxa Gene Expression ◽

Primary Leukemia ◽

Hoxa Gene

Abstract Abstract 405 Somatic mutations in ASXL1 have been identified in patients with myeloid malignancies and are associated with worsened overall survival in AML and MDS patients. However the mechanisms of myeloid transformation of ASXL1 mutations had not been delineated. We therefore performed extensive in vitro and in vivo studies to assess the functional implications of ASXL1 mutations in the hematopoietic compartment. Transcriptional and Western blot analysis demonstrated loss of ASXL1 protein in primary leukemia samples with endogenous ASXL1 mutations indicating that these mutations are loss-of-function disease alleles. Further, ASXL1 depletion by shRNA in normal and malignant hematopoietic cells leads to robust upregulation of a set of genes including the posterior HOXA cluster (HoxA5-HoxA13). Increased HoxA gene expression was confirmed in human hematopoietic stem progenitor cells targeted with ASXL1 siRNA and in mice with conditional deletion of Asxl1 in the hematopoietic compartment. Previous studies in Drosophila had revealed that Asxl forms the polycomb-repressive deubiquitinase (PR-DUB) complex with BAP1, which normally opposes the function of polycomb repressive complex 1 (PRC1) by removing H2AK119 ubiquitination. We verified that wild-type, but not mutant ASXL1 associates with BAP1 in co-immunoprecipitation studies. However, BAP1 depletion in hematopoietic cells did not result in significant changes in HoxA gene expression, suggesting that ASXL1 regulates gene expression in hematopoietic cells independent of its role in the PR-DUB complex. We therefore performed CHIP sequencing for known activating and repressive chromatin marks and histone mass spectrometry to elucidate the genome-wide effects of ASXL1 loss on chromatin state in hematopoietic cells. This allowed us to show that ASXL1 loss resulted in genome-wide loss of the transcriptionally repressive mark H3K27me3 in hematopoietic cells and primary patient samples with ASXL1 mutations. These data were supported by western blot analysis and histone mass spectrometry demonstrating a significant loss of H3K27 trimethylation in ASXL1-mutant cells. Moreover, ASXL1 mutations in primary leukemia samples are characterized by loss of H3K27 trimethylation at the HoxA locus. These data led us to hypothesize that ASXL1 interacts with the PRC2 complex; co-immunoprecipitation studies revealed that ASXL1 associates with members of the PRC2 complex including EZH2 and SUZ12 but not with the PRC1 repressive complex. Importantly, ASXL1 downregulation resulted in loss of EZH2 recruitment to the HOXA locus indicating a role of ASXL1 in recruiting the PRC2 complex to known leukemogenic loci. We next assessed the effects of ASXL1 loss in vivo by generating a conditional knock-out model of ASXL1 and also by employing shRNA to deplete ASXL1 in hematopoietic cells expressing the NRASG12D oncogene. Consonant with the in vitro data, we observed HOXA9 overexpression with ASXL1 loss/depletion in vivo. Preliminary analysis reveals that conditional, hematopoietic specific ASXL1-knockout (ASXL1fl/fl Vav-Cre) mice are characterized by progressive expansion of LSK and myeloid progenitor cells in mice less than 6 months of age. After 6 months of age a significant proportion of ASXL1fl/fl Vav-Cre mice developed leukocytosis, anemia, thrombocytopenia, and splenomegaly; pathologic analysis of tissues revealed a phenotype consistent with myelodysplasia with myeloproliferative features. Moreover, loss of ASXL1 in cooperation with expression of NRasG12D resulted in impaired survival, increased myeloproliferation, and progressive anemia consistent with MPN/MDS in vivo. Taken together, these results reveal that ASXL1 mutations result in a loss-of-function and suggest a specific role for ASXL1 in epigenetic regulation of gene expression by facilitating PRC2-mediated transcriptional repression of known leukemic oncogenes. Moreover, our in vivo data validate the importance of ASXL1 mutations in the pathogenesis of myeloid malignancies and provide insight into how mutations that inhibit PRC2 function contribute to myeloid transformation through epigenetic dysregulation of specific target genes. Disclosures: Carroll: Agios Pharmaceuticals: Research Funding; TetraLogic Pharmaceuticals: Research Funding; Sanofi Aventis Corporation: Research Funding; Glaxo Smith Kline, Inc.: Research Funding.

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A 4‐gene expression score associated with high levels of Wilms Tumor‐1 ( WT 1) expression is an adverse prognostic factor in acute myeloid leukaemia

British Journal of Haematology ◽

10.1111/bjh.13836 ◽

2015 ◽

Vol 172 (3) ◽

pp. 401-411 ◽

Cited By ~ 13

Author(s):

Ahmadreza Niavarani ◽

Tobias Herold ◽

Yasmin Reyal ◽

Maria C. Sauerland ◽

Thomas Buchner ◽

...

Keyword(s):

Gene Expression ◽

Prognostic Factor ◽

Acute Myeloid Leukaemia ◽

Myeloid Leukaemia ◽

Wilms Tumor ◽

Adverse Prognostic Factor ◽

Wilms Tumor 1 ◽

Expression Score ◽

Gene Expression Score ◽

Acute Myeloid

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HOXA GENE EXPRESSION IMPLICATED IN TREATMENT RESISTANCE AND POOR PROGNOSIS IN GLIOBLASTOMA

MNJ (Malang Neurology Journal) ◽

10.21776/ub.mnj.2020.006.02.11 ◽

2020 ◽

Vol 6 (2) ◽

pp. 105-110

Author(s):

Naomi Seidu ◽

Edward Poluyi ◽

Chibuikem Ikwuegbuenyi ◽

Eghosa Morgan

Keyword(s):

Gene Expression ◽

Poor Prognosis ◽

Treatment Resistance ◽

Hoxa Gene Expression ◽

Hoxa Gene

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The CRM1 Nuclear Export Receptor Activates HOXA Gene Expression in Leukemogenesis

Blood ◽

10.1182/blood.v124.21.2190.2190 ◽

2014 ◽

Vol 124 (21) ◽

pp. 2190-2190

Author(s):

Catherine P Lavau ◽

Jessica L Heath ◽

William H Lee ◽

Amanda E Conway ◽

Daniel S Wechsler

Keyword(s):

Gene Expression ◽

Bone Marrow ◽

Transcriptional Activation ◽

Nuclear Export ◽

Leukemia Cells ◽

Nuclear Pore ◽

Myeloid Neoplasms ◽

Hoxa Genes ◽

Hoxa Gene Expression ◽

Hoxa Gene

Abstract HOXA genes are effectors of oncogenic transformation that are frequently upregulated in myeloid and T-cell acute leukemias. Chromosomal translocation-derived oncoproteins, including MLL fusions, NUP (NUP98 or NUP214) fusions or CALM-AF10, bind to HOXA genes and result in their overexpression. We have previously demonstrated that a CRM1-dependent Nuclear Export Signal (NES) within CALM is essential for CALM-AF10’s ability to upregulate HOXA genes and cause leukemia in mice. Interfering with the CRM1/CALM-AF10 interaction by either genetic or pharmacologic inhibition abolishes CALM-AF10’s ability to bind to and activate HOXA gene expression. Furthermore, we showed that CRM1 binds to HOXA loci, suggesting that CRM1 recruits CALM-AF10 to its target genes. To explore whether CRM1 is also involved in the upregulation of Hoxa genes associated with MLL- and NUP98-fusion genes, we measured Hoxa transcript levels in murine leukemia cells treated with the CRM1 inhibitor Leptomycin B (LMB). LMB is a small molecule that covalently binds to the NES binding domain of CRM1 and blocks its ability to interact with NES partner proteins. We found that treatment of MLL-AF10, MLL-ENL, NUP98-HOXA9 or NUP98-AF10 leukemia cells with LMB (1 nM, 2 hours) causes a 50% reduction of Hoxa7, Hoxa9, Hoxa10 and Hoxa11 levels, similar to what is observed in CALM-AF10 leukemia cells. This suggests that in addition to its ability to interact with CALM-AF10, CRM1 may also participate in the transcriptional activation of Hoxa genes caused by MLL- or NUP98-fusion proteins. To demonstrate the importance of the CRM1/CALM interaction in CALM-AF10-dependent oncogenesis, we studied the biological activity of an artificial CRM1-AF10 fusion protein. Using a murine bone marrow clonogenic progenitor replating assay, we found that while native CRM1 overexpression did not result in transformation, the CRM1-AF10 fusion significantly increased the self-renewal of clonogenic progenitors. This effect was even more pronounced when CRM1 was fused to the MLL partner ENL: transduction with a CRM1-ENL fusion gene caused the immortalization of clonogenic bone marrow progenitors. Both CRM1-AF10- and CRM1-ENL-transduced progenitors displayed overexpression of Hoxa genes. To investigate the leukemogenic potential of CRM1-AF10in vivo, we transplanted mice with retrovirally transduced bone marrow progenitors and found that CRM1-AF10 induces myeloid neoplasms with a low penetrance and long latency (after more than a year of observation, 5 of 15 mice developed myeloid neoplasms between 160 and 220 days). These primary CRM1-AF10 leukemias could be transplanted to secondary recipients and cause myeloid leukemias with a shorter latency. Experiments to determine the leukemogenic potential of CRM1-ENLin vivo are ongoing. In contrast to CRM1-AF10, CRM1-ENL-transduced progenitors displayed a marked proliferative advantage in all transplanted mice (assessed by the elevation in the percentage of GFP-expressing CRM1-ENL-transduced cells in the peripheral blood over time); mice transplanted 74 days ago will be followed to determine survival curves. In summary, our results demonstrate that CRM1 regulates the expression of Hoxa genes in mouse leukemia cells, and alteration of CRM1’s activity can drive murine leukemogenesis. This has implications for understanding the mechanisms of HOXA deregulation in human leukemias induced by various fusion oncoproteins. It is noteworthy that in addition to interacting directly with CALM-AF10 through the NES, CRM1 physiologically interacts with NUP98 and NUP214 to facilitate transport through the nuclear pore. Our data also suggest that the anti-tumor effects of CRM1 inhibitors (Selective Inhibitors of Nuclear Export, SINEs) currently undergoing clinical trials, could be mediated, at least in part, by their ability to block the transcriptional activation of tumor-promoting genes by CRM1. Disclosures No relevant conflicts of interest to declare.

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MIR142 loss-of-function mutations derepress ASH1L to increase HOXA gene expression and promote leukemogenesis

Cancer Research ◽

10.1158/0008-5472.can-17-3592 ◽

2018 ◽

pp. canres.3592.2017 ◽

Cited By ~ 4

Author(s):

Maria C. Trissal ◽

Terrence N. Wong ◽

Juo-Chin Yao ◽

Rahul Ramaswamy ◽

Iris Kuo ◽

...

Keyword(s):

Gene Expression ◽

Loss Of Function ◽

Hoxa Gene Expression ◽

Hoxa Gene

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High Serum Vascular Endothelial Growth Factor (VEGF) Level Is An Adverse Prognostic Factor In High Risk Diffuse Large B-Cell Lymphoma (DLBCL) Patients Treated with Dose-Dense Chemoimmunotherapy and Systemic CNS Prophylaxis. Results From a Nordic Phase II Study

Blood ◽

10.1182/blood.v116.21.4142.4142 ◽

2010 ◽

Vol 116 (21) ◽

pp. 4142-4142

Author(s):

Sari Riihijarvi ◽

Heidi Nyman ◽

Harald Holte ◽

Magnus Bjorkholm ◽

Oystein Fluge ◽

...

Keyword(s):

Gene Expression ◽

High Risk ◽

Prognostic Factor ◽

Phase Ii ◽

High Dose ◽

Vegf Gene ◽

Adverse Prognostic Factor ◽

Cns Prophylaxis ◽

Grade 3 ◽

Vegf Level

Abstract Abstract 4142 Background: VEGF is one of the most specific and critical regulators of angiogenesis. It regulates normal endothelial proliferation, permeability, and survival, but is also an angiogenic mediator in tumours, and has been implicated in the pathogenesis and progression of cancer. Elevated serum VEGF (S-VEGF) levels have been associated with unfavourable outcome in different hematologic malignancies including DLBCL. However, to our knowledge there is no data about the prognostic relevance of S-VEGF levels in the rituximab era. The aim of this study was to determine if pretreatment S-VEGF levels and VEGF gene expression in the DLBCL tissue correlate with survival of patients treated with chemoimmunotherapy. Patients and methods: Study population consisted of DLBCL and follicular lymphoma (FL) grade 3 patients, who were less than 65 years old and had high-risk (aaIPI 2–3) disease. All patients were treated in the Nordic phase II protocol with six courses of R-CHOEP14 followed by systemic CNS prophylaxis with one course of high-dose methotrexate and one course of high-dose cytarabine. Pretreatment serum was available for VEGF Enzyme-Linked Immuno-Sorbent Assay (ELISA) from 112 trial patients. VEGF gene expression could be analyzed from the exon-based microarrays of 41 pretreatment biopsies. In the present report of the 112 patients with a median follow-up of 37 months, (range 17–64 months), 3-year relapse free survival (RFS) was 76% and overall survival (OS) 82%. Results: S-VEGF levels at diagnosis varied from undetectable to 2000 pg/ml, median concentration being 530 pg/ml. 10 patients had values higher than the highest standard, 2000 pg/ml. 28 patients (25%) had S-VEGF level higher than 925 pg/ml (highest quartile). According to Kaplan-Meier analyses, RFS at 3 years was poorer among the patients with high (the highest quartile) than low S-VEGF-levels (59% vs 82%, p=0.005) The risk of relapse was 2.9 fold among the patients with high S-VEGF level (95% CI 1.34–6.26, p=0.007). In contrast to serum data, VEGF gene expression in the lymphoma tissue of the same patients did not associate with outcome. Furthermore, no correlation between S-VEGF levels and VEGF gene expression was found. To validate the gene expression results we used microarray data from an independent set of 233 DLBCL patients treated with a combination of rituximab and CHOP-like chemotherapy (Lenz et al., 2008). Again, no correlation with VEGF gene expression and outcome could be observed. Conclusions: High pretreatment S-VEGF level is an adverse prognostic factor for young high-risk DLBCL/FL grade 3 patients treated with chemoimmunotherapy, whereas VEGF gene expression in the lymphoma tissue correlates neither with the S-VEGF levels nor the prognosis. The results suggest that S-VEGF does not necessarily arise from the lymphoma tissue but may instead reflect host response to lymphoma. Disclosures: No relevant conflicts of interest to declare.

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