Genomic profiling of acute myeloid leukaemia associated with ataxia telangiectasia identifies a complex karyotype with wild‐type
            TP53
            and mutant
            KRAS, G3BP1
            and
            IL7R

Abstract Nucleophosmin is commonly both over-expressed and mutated in acute myeloid leukemia (AML). NPM1 mutations are always heterozygous. In addition, NPM1 has a number of different splice variants with the major variant encoded by exons 1–9 and 11–12 (NPM1.1). Further variants include NPM1.2 which lacks exons 8 and 10 and NPM1.3 which comprises exons 1–10 (and so lacks the region of sequence mutated in AML). In this study we quantified the expression of these three variants in 108 AML patient samples with and without NPM1 mutations and also assessed the level of expression from the wild-type and mutant alleles in variants NPM1.1 and NPM1.2. The results show that NPM1.1 is the most commonly expressed variant, however transcripts from wild-type and mutated alleles do not occur at equal levels, with a significant bias toward the mutated allele. Considering the involvement of mutant nucleophosmin in the progression and maintenance of AML, a bias towards mutated transcripts could have a significant impact on disease maintenance.

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Patients with de novo acute myeloid leukaemia and complex karyotype aberrations show a poor prognosis despite intensive treatment: a study of 90 patients

British Journal of Haematology ◽

10.1046/j.1365-2141.2001.02511.x ◽

2001 ◽

Vol 112 (1) ◽

pp. 118-126 ◽

Cited By ~ 125

Author(s):

Claudia Schoch ◽

Torsten Haferlach ◽

Detlef Haase ◽

Christa Fonatsch ◽

Helmut Löffler ◽

...

Keyword(s):

Acute Myeloid Leukaemia ◽

Myeloid Leukaemia ◽

Poor Prognosis ◽

De Novo ◽

Intensive Treatment ◽

Complex Karyotype ◽

Acute Myeloid

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Knockdown of MicroRNA-10a in Acute Myeloid Leukaemia Cells Bearing the Nucleophosmin1 Mutation Causes Cell Death and Reduced Clonogenicity

Blood ◽

10.1182/blood.v118.21.1367.1367 ◽

2011 ◽

Vol 118 (21) ◽

pp. 1367-1367

Author(s):

Adam J Bryant ◽

Catalina A Palma ◽

Mark Lutherborrow ◽

Vivek Jayaswal ◽

Yee Hwa Yang ◽

...

Keyword(s):

Cell Death ◽

Acute Myeloid Leukaemia ◽

Myeloid Leukaemia ◽

Cell Line ◽

Caspase 3 ◽

Luciferase Reporter ◽

Unknown Etiology ◽

Wild Type ◽

Over Expression ◽

Acute Myeloid

Abstract Abstract 1367 Acute Myeloid Leukaemia (AML) with a mutation in the Nucleophosmin1 gene (NPM1c+) accounts for one of the largest subtypes of AML, with an unknown etiology. MicroRNA dysregulation has now been implicated in the oncogenesis of many cancers including AML. We sought to investigate the role of microRNAs in the initiation and development of AML with the NPM1c+ mutation. MicroRNA profiling of bone marrow samples from 28 AML patients and confirmation by qRT-PCR demonstrated a unique microRNA signature in AML-NPM1c+ samples dominated by miR-10a over-expression of 19.6-fold compared to Nucleophosmin1 wild type (NPM1) samples. Functional assessments were performed in the human OCI-AML3 cell line, which is the only cell line to harbour NPM1c+. miR-10a repression was induced by transfection with miRCURY LNA microRNA knockdown probes (Exiqon). Cell growth (MTS) assay demonstrated a significant decrease of 19% in miR-10a knockdown cells compared to the Scrambled control. AnnexinV and Caspase 3 assays assessed the effect of miR-10a knockdown on apoptosis. miR-10a knockdown increased the proportion of AnnexinV positive events when compared to control treated cells by 34.9% and 39.3% at 24 and 48 hours respectively, but had no effect on Caspase 3 expression. Proliferation (BrdU uptake) assays did not show a change, however, clonogenic assays demonstrated a 26.1% decrease in colony number in miR-10a knockdown cells compared to the control. Potential mechanisms were elucidated by determining miR-10a mRNA targets in silico and confirmed by luciferase reporter assays. These included ARNT, GTFH1, ID4, KLF4, MAPRE1, NR4A3, RB1CC1 and TFAP2C. In this study, we have demonstrated that miR-10a was highly differentially expressed between AML-NPM1c+ cells compared to leukaemic cells bearing wild type NPM1. Knockdown of miR-10a in OCI-AML3 cells resulted in increased cell death as detected by AnnexinV binding (but not Caspase 3, indicating an effect independent of the classical apoptotic pathways) and reduced clonogenic capacity. These effects are thought to occur through miR-10a mediated modulation of ARNT, GTFH1, ID4, KLF4, MAPRE1, NR4A3, RB1CC1 and TFAP2C, all of which are associated with neoplastic transformation. Taken together, our results suggest that aberrant miR-10a over-expression in AML-NPM1c+ patients promotes cell survival. Disclosures: No relevant conflicts of interest to declare.

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Hydroxyurea synergizes with valproic acid in wild-type p53 acute myeloid leukaemia

Oncotarget ◽

10.18632/oncotarget.6991 ◽

2016 ◽

Vol 7 (7) ◽

pp. 8105-8118 ◽

Cited By ~ 11

Author(s):

Calum Leitch ◽

Tereza Osdal ◽

Vibeke Andresen ◽

Maren Molland ◽

Silje Kristiansen ◽

...

Keyword(s):

Valproic Acid ◽

Acute Myeloid Leukaemia ◽

Myeloid Leukaemia ◽

Wild Type ◽

Wild Type P53 ◽

Acute Myeloid

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Nitroreductase-Mediated Release of Inhibitors of Lysine-Specific Demethylase 1 (LSD1) from Prodrugs in Transfected Acute Myeloid Leukaemia Cells

10.26434/chemrxiv.10012937 ◽

2019 ◽

Author(s):

Manfred Jung ◽

Eva-Maria Herrlinger ◽

Mirjam Hau ◽

Desiree M. Redhaber ◽

Gabriele Greve ◽

...

Keyword(s):

Acute Myeloid Leukaemia ◽

Myeloid Leukaemia ◽

Specific Inhibition ◽

Cellular Activity ◽

Wild Type ◽

Site Specific ◽

Lysine Specific Demethylase ◽

Organ Type ◽

Promising Therapeutic Target ◽

Acute Myeloid

Lysine-specific demethylase 1 (LSD1) has evolved as a promising therapeutic target for cancer treatment, especially in acute myeloid leukaemia (AML). To approach the challenge of site-specific LSD1 inhibition, we developed an enzyme-prodrug system with the bacterial nitroreductase NfsB (NTR) that was expressed in the virally transfected AML cell line THP1-NTR+. The cellular activity of the NTR was proven with a new luminescent NTR probe. We synthesised a diverse set of nitroaromatic prodrugs that by design do not affect LSD1 and are reduced by the NTR to release an active LSD1 inhibitor. The 2-nitroimidazolyl prodrug (1f) of a potent LSD1 inhibitor emerged as one of the best prodrug candidates with a pronounced selectivity window between wild-type and transfected NTR+ cells. Our prodrugs are selectively activated and release the LSD1 inhibitor locally in turn blocking colony formation. This system may be applied in future targeting approaches to reach tissue- or organ-type-specific inhibition of LSD1.<br>

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Successful treatment of acute myeloid leukaemia in a patient with ataxia telangiectasia

European Journal Of Haematology ◽

10.1111/ejh.12186 ◽

2013 ◽

Vol 91 (6) ◽

pp. 557-560 ◽

Cited By ~ 4

Author(s):

Tadashi Onoda ◽

Miyako Kanno ◽

Toru Meguro ◽

Hiroko Sato ◽

Noriyuki Takahashi ◽

...

Keyword(s):

Acute Myeloid Leukaemia ◽

Myeloid Leukaemia ◽

Successful Treatment ◽

Ataxia Telangiectasia ◽

Acute Myeloid

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Genes Located within the del(9q) Commonly Deleted Region Are Down-Regualted in Acute Myeloid Leukaemia.

Blood ◽

10.1182/blood.v104.11.2040.2040 ◽

2004 ◽

Vol 104 (11) ◽

pp. 2040-2040

Author(s):

Zheng Zhao ◽

Sarah Daly ◽

John Liu Yin ◽

David Sweetser ◽

Jacqueline Boultwood ◽

...

Keyword(s):

Acute Myeloid Leukaemia ◽

Myeloid Leukaemia ◽

Normal Karyotype ◽

Complex Karyotype ◽

Down Regulation ◽

Expression Levels ◽

Normal Individuals ◽

Low Expression ◽

Acute Myeloid

Abstract Deletions of 9q are recurring cytogenetic abnormalities in acute myeloid leukaemia (AML). In approximately one-third of cases del(9q) occurs in association with t(8;21). We have previously identified a 2.4Mb region located on 9q21.32–21.33 which is deleted in cases of del(9q) AML - the del(9q) commonly deleted region (CDR). This region encodes 11 genes which we have also previously shown not to be mutated in del(9q) AML. In order to further investigate the role of these genes in AML and in particular to elucidate the pathogenesis of del(9q) AML we have examined the expression of these genes in AML. RNA was extracted from the bone marrow or peripheral blood of patients with AML at the time of diagnosis. Patient samples from the following cytogenetic subgroups were included in this study: (1) del(9q) AML (n=8) - this includes 3 patients with associated t(8;21); (2) t(8;21) but no del(9q) (n=15); (3) Normal karyotype (n=6); (4) Complex Karyotype (n=6). Taqman assays were designed for 9 of the 11 genes located within the del(9q) CDR: FRMD3; ENSG00000148057; UBQLN1; GKAP42; Q9UF54; Q8N2B1; Q9H9A7; SLC28A3; NTRK2. For the other 2 genes within the region Taqman assays could not be performed because of uniformly low expression levels (Q8IZ41) and lack of specificity of primer-design (HNRPK). CD34-purified progenitors from normal individuals were used as controls. It was found that 6 of the 9 genes were significantly down-regulated in del(9q) AML (p<0.05): ENSG00000148057; UBQLN1; Q9UF54; Q8N2B1; Q9H9A7; NTRK2. Since del(9q) is commonly associated with t(8;21), cases of t(8;21) in which del(9q) was not present were also analysed for the expression levels of the del(9q) CDR genes. It was found that 5 of the 9 genes were significantly down regulated in t(8;21) AML (ENSG00000148057; Q9UF54; Q8N2B1; Q9H9A7; SLC28A3) (p<0.05). Only two of these genes were found to be down-regulated in AML of normal karyotype (Q9H9A7 and UBQLN1) (p<0.05) and no significant down-regulation was detected in any of these genes in AML of complex karyotype. Our findings indicate that several genes from within the del(9q) AML CDR are down-regulated in del(9q) AML. A similar pattern of down-regulation is found in cases of t(8;21) even in the absence of del(9q) AML. This suggests that down-regulation of one or more of these genes may be important in the pathogenesis of AML. It may therefore be hypothesized that this pattern of gene down-regulation provides a mechanism common to the development of AML with both del(9q) and t(8;21).

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Identification and Analysis of Oncogenic Pathways in Deletion 20q Acute Myeloid Leukaemia

Blood ◽

10.1182/blood.v120.21.1324.1324 ◽

2012 ◽

Vol 120 (21) ◽

pp. 1324-1324

Author(s):

Matthew Ku ◽

Nisha Narayan ◽

Meaghan Wall ◽

Ruth N. MacKinnon ◽

Lynda J Campbell ◽

...

Keyword(s):

Acute Myeloid Leukaemia ◽

Myeloid Leukaemia ◽

Bone Marrow Cells ◽

Conflicts Of Interest ◽

Tyrosine Phosphatase ◽

Wild Type ◽

Src Tyrosine Kinase ◽

Chromosome 20 ◽

Stat3 Phosphorylation ◽

Acute Myeloid

Abstract Abstract 1324 Deletion of the long arm of chromosome 20 [del(20q)] is a common recurrent chromosomal abnormality in acute myeloid leukaemia (AML). It is a key step in AML development and a better understanding of the associated molecular events is important. The abnormal chromosome 20 in del(20q) AML has been shown to have lost a “Common Deleted Region” (CDR) that contains Protein Tyrosine Phosphatase Receptor T (PTPRT), a tyrosine phosphatase that is mutated in many human cancers such as AML. We have previously reported (MacKinnon et al, Genes, Chromosomes and Cancer 2010) that del(20q) also harbours an amplified “Common Retained Region,” (CRR) which contains Haemopoietic Cell Kinase (HCK). HCK is anoncogenic Src tyrosine kinase and its aberrant activation has been shown to contribute to the pathogenesis of some haematological malignancies. We hypothesize that the amplification of HCK in the CRR cooperates with the loss of PTPRT in the CDR to cause AML. Our model proposes that AML occurs either through direct interaction between HCK and PTPRT, or through aberrant activation of Signal Transducer and Activator of Transcription 3 (STAT3), a cytoplasmic second messenger that is important in cellular signalling. Constitutively activated STAT3 has been shown to be oncogenic in several malignancies, including AML. STAT3 is a direct target of both HCK and PTPRT. It is phosphorylated (hence activated) by HCK, and dephosphorylated (hence inactivated) by PTPRT. This provides a downstream leukaemogenic pathway for our model. The ultimate aim of our experiments is to prove this hypothesis using mouse models. Murine haemopoietic stem cells (HSC) were isolated from the bone marrows of wild type C57BL/6 (WT) and PTPRT-null mice by Fluorescence Activated Cell Sorting for Lineage negative, C-kit and Sca-1 positive (LKS+) cells. Retroviral constructs of HCK were generated by cloning it into the retroviral vector pMSCViresEGFP(MIG), with GFP as reporter. Murine HSC were transduced with either retroviral HCK or MIG vector control and Phoenix cell system was used for retroviral packaging. Experiments using isolated LKS+ HSC were performed to examine for features of AML. Examination of bone marrow cells from del(20q) AML patients by quantitative PCR revealed an increase in HCK mRNA expression and a reduction in PTPRT expression. Wild type (WT) and PTPRT-null murine HSC transduced with either MIG or HCK were cultured in methylcellulose media. Colony forming units (CFU) were enumerated on day7 and day12. We found that both WT and PTPRT-null HSC transduced with HCK showed a significant increase in colony numbers compared to MIG transduced HSC. Furthermore, the fold increment in colony number was higher in the PTPRT-null genotype as shown in figure 1. Moreover, an intracellular anti-phosphoSTAT3 assay was performed to assess STAT3 phosphorylation levels in the transduced HSC. It demonstrated that in both WT and PTPRT-null HSC that have been transduced with HCK, STAT3 hyperphosphorylation, and hence overactivation, occured. This response was again more exaggerated in the PTPRT-null HSC, as seen in figure 2. We are currently transplanting transduced LKS+ HSC (either MIG or HCK) into lethally irradiated murine recipients to assess AML formation in a reconstitution study. The recipient mice will be assessed for evidence of engraftment and subsequent AML. The preliminary data reveals a likely new oncogenic-signalling cascade: that HCK amplification and loss of PTPRT in del(20q) AML may cooperate to cause AML directly, or by aberrant activity of hyperphosphorylated STAT3. Disclosures: No relevant conflicts of interest to declare.

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