DEAH-Box Splicing Factor Gene, Prp16 Amplification in Acute Myeloid Leukemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4479-4479
Author(s):  
Yupo Ma ◽  
Tammy Barnett ◽  
Li Chai ◽  
Jianchang Yang ◽  
Zaida Alipio ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Mrna Expression ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Expression Profiles ◽  
Mrna Splicing ◽  
Splicing Factor ◽  
Aberrant Expression ◽  
Factor Gene ◽  
Acute Myeloid

Abstract Aberrant mRNA splicing has been observed frequently in solid tumors and shown to play a functionally significant role in tumorgenesis. Here we demonstrate that the DEAH-Box splicing factor gene, Prp16, is amplified in fresh human acute myeloid leukemia (AML) and in established AML cell lines. Prp16, an RNA-dependent ATPase required for pre-mRNA splicing, maps to chromosome 16q22, a region frequently altered in AML. Amplification of the Prp16 gene was initially detected using digital karyotyping, a powerful technique for analyzing genome-wide alterations in DNA copy number and verified by quantitative real-time PCR. Analysis of mRNA expression profiles revealed that Prp16 transcripts were present at high levels in 22 of 39 cases of AML (56%) and in both AML cell lines examined. There was a strong correlation between gene amplification and mRNA expression levels. To our knowledge, this is the first demonstration linking aberrant expression of a splicing enzyme to leukemogenesis. The classification and clinical outcome of the AML cases is being correlated with the presence or absence of Prp16 amplification. The identification of leukemia-specific splicing event(s) may provide a novel target for therapeutic intervention.

Aberrant Expression of the Homeobox Gene CDX2 in Acute Myeloid Leukemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 8-8 ◽  
Author(s):  
Claudia Scholl ◽  
Dimple Bansal ◽  
Konstanze Dohner ◽  
Karina Eiwen ◽  
Benjamin H. Lee ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Gene Copy ◽  
Coding Region ◽  
Aberrant Expression ◽  
Cdx2 Expression ◽  
Frequent Event ◽  
Acute Myeloid

Abstract The caudal-type homeobox transcription factor 2 (CDX2) plays an important role in embryonic development and regulates the proliferation and differentiation of intestinal epithelial cells in the adult. Ectopic expression of CDX2 in the hematopoietic compartment was previously identified as the key pathogenetic event in a single patient with acute myeloid leukemia (AML) and t(12;13)(p13;q12). Using real-time quantitative PCR, we detected aberrant CDX2 expression in 153 (90%) of 170 patients with AML, in patients with high-risk myelodysplastic syndrome or advanced-stage chronic myeloid leukemia, and in several AML cell lines, but not in bone marrow derived from normal individuals. Expression of CDX2 was monoallelic in the majority of cases with informative single-nucleotide polymorphisms in the CDX2 coding region, but was not related to mutations in the CDX2 coding region or in the predicted CDX2 promoter sequence, gene-specific hypomethylation of the CDX2 promoter, or increased CDX2 gene copy numbers. Stable knockdown of CDX2 expression by lentivirus-mediated RNA interference inhibited the proliferation of various human AML cell lines exhibiting CDX2 transcript levels that were in the range of those observed in most primary AML samples, and strongly reduced their clonogenic potential in vitro. Primary murine hematopoietic progenitor cells transduced with Cdx2 acquired serial replating activity in vitro, could be continuously propagated in liquid culture, generated a fully penetrant and transplantable AML in vivo, and displayed dysregulated expression of Hox family members. Together, these results (i) demonstrate that aberrant expression of CDX2 is a frequent event in myeloid leukemogenesis, (ii) suggest a role for CDX2 as part of a common effector pathway that increases the proliferative capacity and promotes the self-renewal potential of hematopoietic progenitors, and (iii) support the unifying hypothesis that CDX2 is responsible, at least in part, for abnormalities in HOX gene expression in AML.

MYB Overexpression Is Directly Involved in Acute Myeloid Leukemia Pathogenesis and Could Constitute a New Therapeutic Target for Patients with Aberrant Expression of This Gene.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2402-2402 ◽  
Author(s):  
Carmen Vicente ◽  
Ana Conchillo ◽  
Daphnie Pauwels ◽  
Iria Vazquez ◽  
Laura Garcia-Orti ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Complete Remission ◽  
Synergistic Effect ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Lymphoblastic Leukemia ◽  
Recurrent Event ◽  
Aberrant Expression ◽  
Acute Myeloid

Abstract Abstract 2402 Poster Board II-379 The MYB proto-oncogene encodes a nuclear transcription factor with an essential role in proliferation, lineage commitment, and differentiation of hematopoietic progenitor cells. Proper levels of MYB are known to be important during hematopoietic cell development, and the Myb gene is a frequent target of retroviral insertions in myeloid, B- and T-cell leukemias in the mouse. Overexpression of MYB in T-acute lymphoblastic leukemia (T-ALL) causes a differentiation block of the T cells, and it has been shown that NOTCH1 mutation and MYB duplication cooperate in the pathogenesis of T-ALL. Our aim was to study the role of MYB in the pathogenesis of acute myeloid leukemia (AML), and to investigate its potential as a target for therapy. We functionally characterized MYB in 15 AML cell lines. Twelve of the 15 cell lines tested had MYB overexpression. Knockdown of MYB by siRNA in these cell lines caused decreased cell viability and proliferation, and reduced the clonogenic capacity, that could be explained in some cell lines by changes on the stage of cell differentiation. These results show that MYB overexpression is involved in the pathogenesis of AML. Moreover, knockdown of MYB in combination with common AML treatments (Idarubicin, Cytarabine and Sorafenib) had a strong synergistic effect on proliferation and viability of cells, suggesting that MYB could be a new target for therapy in AML. These observations prompted us to quantify MYB expression in a cohort of 159 patients with AML at diagnosis. We detected MYB overexpression in 14.5% (23/159) patients, with a higher prevalence within the intermediate prognosis group (17/83, 20.5%), particularly in patients with normal karyotype (NK) (14/62, 22.6%). Interestingly, 33% of patients without FLT-3 ITD and NPM1 mutations had MYB overexpression. To study the prognosis impact of MYB overexpression in AML, we performed a survival analysis in a preliminary series of 100 AML patients at diagnosis. As expected, significant differences in OS according to age, complete remission and cytogenetic prognostic group were found (p<0.01). MYB overexpression had no significant impact in the OS; however, this genetic marker allowed distinguishing a group of patients with a worse outcome within the group that did not get complete remission after treatment. Recently it has been described that MYB duplication causes elevated MYB expression in T-ALL; we detected duplication of MYB in 2 of 13 AML cell lines and in 2 patients with MYB overexpression (2/23, 8.6%). In conclusion, these results show that aberrant expression of MYB is involved in the activation of pathways responsible for the increased proliferative and clonogenic capacity that is characteristic of AML, independently of other genetic aberrations. Moreover, we show that MYB overexpression is a recurrent event in AML, especially in the subgroup of patients with NK, and that MYB could cooperate with other mutations in the leukemic transformation, as described previously in T-ALL. The synergistic effect of combined treatments with MYB knockdown, suggest that MYB silencing could be a new target for therapy in patients with AML and MYB overexpression. Disclosures: No relevant conflicts of interest to declare.

Epigenetic Inactivation of DBC1 in Acute Myeloid Leukaemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4429-4429
Author(s):  
Chen Zhao ◽  
Aili Dai ◽  
Ling Chen ◽  
Xiaoping Sun ◽  
Xin Han ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Mrna Expression ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Hematological Malignancies ◽  
Conflicts Of Interest ◽  
Cell Lymphoma ◽  
Lymphoblastic Leukemia ◽  
B Cell Lymphoma ◽  
Acute Myeloid

Abstract Abstract 4429 DNA hypermethylation has important implications in the tumorigenesis and prognosis in acute myeloid leukemia (AML). To identify relevant methylated genes in AML, we have compared several expression and methylation profilings. With expression analysis, we identified that TRPC6, DBC1, DCC and SOX9 have decreased expression levels in the most analyzed AML cell lines. Among these candidates, DBC1 (deleted bladder cancer 1), a putative tumor suppressor, drew our attention because it is frequently methylated not only in hematological malignancies, including diffuse large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, and acute lymphoblastic leukemia, but also in epithelial cancers. DBC1 may play an important role in the regulation of cell growth and programmed cell death. But the mechanisms of transcriptional control and function role in the hematological malignancies, especially on acute myeloid leukemia, are not well known. In this study, we analyzed the DBC1 expression pattern in 9 AML cell lines with RT-PCR analysis. DBC1 mRNA expression was observed in normal bone-marrow but diminished expression in all of 9 AML cell lines. DBC1 methylation was frequently observed in AML cells (9 of 9, 100%) and inversely correlated with DBC1 mRNA expression in a COBRA analysis (Combined Bisulfite Restriction Analysis). We also detected a frequent methylation of DBC1 in primary AML patient samples (9 of 9, 100%). These findings indicate that DBC1 is frequently silenced by hypermethylation in AML. We are in the process of investigation the functional role of DBC1 in the pathogenesis. In addition, diagnostic and prognostic values of DBC1 in AML are being pursued.* Chen Zhao and Aili Dai contributed equally to the presented work. Disclosures: No relevant conflicts of interest to declare.

The PARP Inhibitor Olaparib Antagonizes Leukemic Growth Induced By TET1 Overexpression in AML1-ETO Positive Acute Myeloid Leukemia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4063-4063 ◽  
Author(s):  
Shiva Bamezai ◽  
Jing He ◽  
Deniz Sahin ◽  
Fabian Mohr ◽  
Fabio Ciccarone ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Cell Growth ◽  
Cell Line ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Parp Inhibitor ◽  
Leukemic Cell ◽  
Aberrant Expression ◽  
Acute Myeloid

Abstract DNA methylation patterns are highly deregulated in human acute myeloid leukemia (AML) cases and stratify AML patient samples into different subgroup. AML1-ETO is the most commonly occurring fusion gene in AML and these AML cases exhibit an aberrant and distinct methylation pattern. So far, the underlying mechanisms for this are only poorly understood. The TET1 dioxygenase has recently emerged as an important epigenetic modifier: by catalyzing the conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) TET1 plays an important role in active demethylation, thereby regulating a variety of biological processes. It was linked to tumorigenesis based on the observation that its expression is frequently deregulated in solid cancer. However, the role of TET1 in AML1-ETO+ (AE+)human AML cases is yet unexplored. Using quantitative real time (qRT)- PCR we now show that AE+ AML is characterized by high and aberrant expression of TET1: the gene was significantly higher expressed in the majority of AE+ patients (n=7, p<0.01) compared to other AML subtypes such as inv(16) (n=11), PML-RARα+ (n=31), cytogenetically normal (CN)-AML patients (n=33) and CD34+ normal BM cells (n=4). This observation was consistent with published cDNA microarray data on large patient cohorts (Haferlach et al., JCO 2010, p<0.008 t-test, p<0.01 Anova) and recently published transcriptome data (TCGA) of AML patients. In contrast to TET1, TET2 and TET3 did not show significant higher expression in AE+ patients compared to other AML subtypes. In line with patient data, TET1 was highest expressed in the AE+ AML cell line KASUMI-1 and SKNO-1 compared to other AML cell lines (p<0.05 and n=3). Compared to normal CD34+ and myeloid (CD33+, CD15+ and CD14+) cells (n=3), TET1 was 10-fold and 16-fold higher expressed in AE+ patient samples (n= 7). Aberrant expression of TET1 in AE+ leukemic cells was associated with hypomethylation of its promoter and enrichment for H3K4me3 euchromatic marks at its promoter as determined by LC/MS and ChIP-qPCR respectively. Knockdown (KD) of TET1 mRNA using two short hairpin RNAs (shRNAs) in AE+ AML cell lines impaired their cell growth and clonogenicity by over 50% in vitro (n=3 and p<0.01). shRNA mediated depletion of TET1 did not impact the cell growth and clonogenicity of the TET1 negative cell line RAJI, ruling out off target effects of the shRNAs (n=3). In mice, KD of Tet1 in leukemic bone marrow cells expressing the truncated leukemogenic AML1-ETO9a (AE9a) fusion, dramatically inhibited cell growth (>60% compared to scrambled, n=3, p<0.01), clonogenicity (>50-70% reduction in primary CFCs, p<0.01, n=3) and importantly delayed onset of leukemia in vivo (median survival 35 days for scr vs 80 days for shRNA mice, n=4/arm, p<0.03). Tet1-knock-out c-kit+ hematopoietic stem and progenitor cells (HSPCs) transduced with AE9a showed reduced primary colony formation and impaired serial replanting capacity in vitro compared to AE9a transduced Tet1-wild-type HSPCs (>50% and >70%, respectively; p<0.001, n=3). Global analysis of 5hmC and 5mC levels using hMeDIP/MeDIP-seq performed on TET1 depleted KASUMI-1 cells revealed lower global 5hmC levels and increase in 5mC as compared to cells transduced with scrambled control (n=2). 3324 promoter regions lost 5hmC and gained 5mC upon TET1 depletion (-5kTSS, Fold enrichment cut off <2-fold, q-value<1e5). Recent studies have shown that PARP activity induces TET1 expression by regulating its promoter epigenetically. We could show that aberrant TET1 expression could be antagonized by the PARP inhibitor olaparib in AE+ leukemic cell lines. Furthermore, olaparib treatment decreased 5hmC levels and reduced cell growth and clonogenicity of human AE+ cell lines and of the murine AE9a+ leukemic cell line in vitro (n=3, p<0.01). In conclusion, our data indicates that aberrant TET1 expression contributes to the growth of AE+ AML by maintaining the 5-hydroxymethylome and that the PARP inhibitor olaparib can at least partially antagonize the oncogenic effect of TET in AML. Disclosures Mulaw: NuGEN: Honoraria. Buske:Celltrion, Inc.: Consultancy, Honoraria.

BEX1, a Marker for Acute Myeloid Leukemia Cell Lines with MLL Rearrangements.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3013-3013
Author(s):  
Hilmar Quentmeier ◽  
Wilhelm G. Dirks ◽  
Robert Geffers ◽  
Cord C. Uphoff ◽  
Hans G. Drexler
Keyword(s):  
Gene Expression ◽  
Acute Myeloid Leukemia ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Hox Genes ◽  
Expression Profiles ◽  
Pcr Analysis ◽  
Wild Type ◽  
Acute Leukemias ◽  
Acute Myeloid

Abstract Patients with acute leukemias carrying MLL rearrangements have a poor prognosis. The tumor cells show characteristic gene expression profiles with increased levels of selected HOX genes (1). We have shown that acute lymphoblastic leukemia (ALL) cell lines with and without MLL rearrangements could likewise be recognized by analysis of HOX gene expression (2). In contrast, MLL wild-type (MLLwt) and mutant (MLLmu) acute myeloid leukemia (AML) cell lines could not be distinguished by analysis of HOX genes, because even wild-type cell lines had a high expression background (2). It was our aim to find out whether MLLwt and MLLmu AML cell lines could be discriminated on the basis of gene expression - other than HOX genes. We performed gene expression analysis with pooled RNAs of MLLmu (n=8) and MLLwt (n=8) cell lines applying high density oligonucleotide Genechips from Affymetrix (HG-U133A). Defensin alpha4 (83x), defensin beta1 (32x), cathepsinG (9x) and FLT3 (7x) genes were overexpressed in MLLmu cell lines, stabilin1 (82x) and galectin10 (55x) in MLLwt cell lines. PCR analysis with individual (non-pooled) cDNAs of the 16 cell lines showed that none of the above genes was exclusively expressed by MLLmu or MLLwt cells. Thus, pooling RNAs has a major disadvantage: many PCRs have to be performed to establish faithful expression profiles for individual samples. BEX1 finally proved to be a gene that was exclusively overexpressed in one group of cell lines. It had been an interesting candidate already after oligonucleotide chip analysis, being both overexpressed (18x) in MLLmu cell lines, and - in contrast to the genes listed above - not a marker of myeloid differentiation. BEX1 is reportedly expressed in brain, testis and ovary, but not in peripheral blood leukocytes, lymph node and bone marrow (3). By RT-PCR analysis we showed that 7/8 MLLmu and 0/8 MLLwt cell lines expressed BEX1. Screening a panel of 54 hematopoetic cell lines gave the same result: BEX1 expression was restricted to MLLmu AML cell lines: 8/11 (73%) MLLmu AML cell lines expressed BEX1, but 43 other hematopoetic cell lines (including Hodgkin′s disease, anaplastic large cell lymphoma, ALL and MLLwt AML cell lines) tested negative. BEX1 expression may depend on the type of MLL rearrangement or the histological background of the cells, as MLLmu ALL cell lines (0/5) also tested negative. It has been shown in the mouse system, that BEX family members may be involved in cell signalling processes. Thus it will be interesting to elucidate whether BEX1 also participates in proliferative/antiapoptotic signalling processes in MLLmu AML cell lines.

Comprehensive Sequence Analysis of Relapse and Refractory Pediatric Acute Myeloid Leukemia Identifies miRNA and mRNA Transcripts Associated with Treatment Resistance - a Report from the COG/NCI-Target AML Initiative

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 687-687 ◽  
Author(s):  
Emilia L. Lim ◽  
Diane L. Trinh ◽  
Rhonda E. Ries ◽  
Yussanne Ma ◽  
James Topham ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Mrna Expression ◽  
Myeloid Leukemia ◽  
Expression Profiles ◽  
Treatment Resistance ◽  
Ribosomal Genes ◽  
Survival Analyses ◽  
Pediatric Aml ◽  
Acute Myeloid ◽  
Cell Stem Cell

Abstract Introduction Induction chemotherapy results in complete remission in 80% of children with acute myeloid leukemia (AML). However, many patients either fail to achieve a remission, or relapse after an initial response and subsequently die of their disease. Although large numbers of somatic karyotypic and molecular alterations have been identified, the majority of them do not indicate a specific target or distinct pathway that can be readily exploited for therapeutic intervention. Materials & Methods As part of a genome-scale approach to identify prognostic markers and therapeutic targets, we provide a comprehensive characterization of the pediatric AML transcriptome, detailing miRNA & mRNA expression patterns and miRNA:mRNA interactions that are characteristic of the disease. A total of 676 patients were considered for this study. Our discovery cohort consisted of miRNA-seq from 259 primary, 22 refractory and 38 relapse samples, and mRNA-seq from 158 primary, 12 refractory and 47 relapse samples. We confirmed our survival analyses on a validation cohort that consisted of miRNA-seq and mRNA-seq from 378 and 87 primary samples, respectively. Unsupervised non-negative matrix factorization (NMF) was used to identify patient subgroups based on miRNA/mRNA expression. To identify miRNA/mRNA expression associated with patient survival, Cox proportional hazards analysis was performed. Wilcoxon tests were performed to identify differentially expressed miRNAs/mRNAs between samples. To screen for functional miRNA:mRNA interactions, we identified miRNA and mRNA pairs with anti-correlated expression profiles and miRNA binding site predictions consistent with miRNA:mRNA interaction. Results Survival analysis of both the discovery and validation cohorts revealed that 6 miRNAs were associated with overall survival (OS) and event free survival (EFS) (p-val<0.05, q-val<0.1): miR-181c-3p and miR-378c were associated with superior OS and EFS (Hazard Ratio (HR): 0.79-0.88), while miR-106a-3p, miR-106a-5p, miR-363-3p and miR-20b-5p were associated with inferior OS and EFS (HR: 1.14-1.36). All 4 of the miRNAs that were associated with inferior survival are members of the polycistronic miR-106a-363 cluster. Differential expression analysis revealed that miR-106a-363 was abundantly expressed in relapse and refractory samples and in primary samples of refractory patients (q-val<0.05). Integrative miRNA:mRNA expression analysis and luciferase reporter assays further revealed that targets of miR-106a-5p include NDUFC2, NDUFA10, UQCRB, ATP5J2-PTCD1 and ATP5S. Interestingly, these genes are involved in oxidative phosphorylation, a process that is suppressed in treatment-resistant leukemic cells[1]. NMF clustering of miRNA expression profiles revealed 2 groups of patients, with each group characterized by particular genomic alterations: Group 1 cases were enriched for NPM1 mutation and FLT3 -ITD, while Group 2 cases were enriched for t(8;21), inv(16), MLL rearrangements and CEBPA mutation (Fisher's exact test p-val<0.05). NMF clustering of mRNA expression revealed 5 groups of patients, in which the group with abundant expression of ribosomal genes was further distinguished by superior OS and EFS (log-rank p-val<0.05). Analysis of the mRNA data showed a decrease in expression of one mRNA isoform of ribosomal protein L28 (RPL28) in relapse samples (q-val<0.05). In addition, survival analyses revealed that abundant expression of ribosomal protein L10 (RPL10) is associated with superior OS in both the discovery and validation cohorts (p-val<0.05, q-val<0.1, HR: 0.78 & 0.47). Conclusions Through a detailed analysis of the transcriptome (Figure A), we identified miRNAs whose expression levels were significantly associated with clinical outcome. In addition, we showed that abundant expression of miR-106a-363 might contribute to treatment resistance by modulating genes involved in energy metabolism. We also demonstrated that reduced expression of ribosomal genes is associated with inferior outcomes, suggesting a dysregulation of protein translation in treatment resistance. Overall, our transcriptome profiles provide clinically meaningful data for risk and response identification and define novel pathways that may be amenable to therapeutic targeting. Figure 1. Summary of the pediatric AML transcriptome Lagadinou ED, et al. Cell Stem Cell. 2013. Figure 1. Summary of the pediatric AML transcriptome. / Lagadinou ED, et al. Cell Stem Cell. 2013. Disclosures No relevant conflicts of interest to declare.

scholarly journals The Pan-Clk/Dyrk Inhibitor Cirtuvivint (SM08502) Exposes Mechanistic Underpinnings of Alternative Splicing As a Therapeutic Vulnerability in Heme Malignancies

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2950-2950
Author(s):  
Carine Bossard ◽  
Elizabeth A. McMillan ◽  
Emily Creger ◽  
Brian Eastman ◽  
Chi-Ching Mak ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Alternative Splicing ◽  
Cell Viability ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Splice Junction ◽  
Mrna Splicing ◽  
Drug Induced ◽  
The Past ◽  
Acute Myeloid

Abstract Mutations in spliceosomal genes are one of the most common classes of somatic alterations in patients with Myelodysplastic Syndrome (MDS) and occur across the entire spectrum of myeloid malignancies, including 10‒25% of patients with acute myeloid leukemia (AML). These mutations occur in higher proportions in AML subjects greater than 60 years of age, or when AML has transformed from an antecedent MDS. Spliceosomal gene mutations are implicated in the production of pathological RNA splicing patterns that block cell differentiation and maintain a myeloid precursor phenotype. This suggests deranged pre-mRNA splicing is a mechanistic determinant of many heme malignancies and, as such, has provoked interest in therapeutic modulation of pre-mRNA splicing as a treatment paradigm. The CLK/DYRK family of protein kinases has been recognized as an integration hub for signal transduction-dependent modulation of alternative pre-mRNA splice junction selection through direct phosphorylation of the serine/arginine-rich splicing factor (SRSF) splice junction enhancer-binding proteins. Thus, these kinases potentially represent a druggable intervention point in alternative splicing-dependent cancers. The isoquinoline SM08502 (cirtuvivint) is a potent ATP-competitive inhibitor of the Cdc2-like kinases (CLK1-4) and the dual specificity tyrosine phosphorylation-regulated kinases (DYRK1-4) with activity against only a minimal number of the remaining members of the CMGC-family kinases and the kinome as a whole. Here the consequence of pan-CLK/DYRK kinase inhibition on cell viability and tumorigenicity was evaluated across a panel of human tumor-derived AML, DLBCL, MCL, myeloma, T-ALL, and CML/CLL models. EC 50s in response to cirtuvivint ranged from 0.014 μM‒0.495 μM in 4-day in vitro cell viability assays, with low-dose responders enriched in subsets of AML, myeloma, DLBCL, MCL and T-ALL. Cell viability EC 50s were associated with induction of programed cell death at drug exposures that inhibited accumulation of phosphorylated SRSF proteins and the anti-apoptotic protein MCL-1. To directly evaluate the contribution of CLK/DYRK kinases to alternative splicing profiles, high-depth RNAseq analysis was performed across 4 cell lines (3 acute myeloid leukemia cell lines and 1 mantle cell lymphoma cell line) +/- a 6-hour exposure to 1µM cirtuvivint. Both baseline and drug-induced changes in alternative splicing events (ASEs) were measured using a multivariate analysis of splicing transcripts (rMATS). The frequency of cirtuvivint-induced ASEs was approximately 20% of total detected ASEs. Concordant drug-induced ASEs among the tested cell lines were in genes enriched in pathways known to drive oncogenesis in hematopoietic lineages, including the MAP kinase and mTOR signaling pathways. Tumor growth inhibition assays in immunocompromised mice showed a range of model-specific responses, including tumor stasis and partial to complete tumor regression at clinically relevant exposures. A cell-based synthetic-lethal screen of cirtuvivint across 36 small molecule inhibitors identified multiple BCL-2 inhibitors among the most prominent synergistic combinations. Consistent with this, combination of the BCL-2 inhibitor venetoclax with cirtuvivint was sufficient to induce tumor regressions in AML xenograft models (KG-1 and HL-60) that were resistant to either single-agent drug at the same concentrations. These observations support further evaluation of CLK/DYRK inhibitors as a therapeutic strategy for heme malignancies dependent upon alternative pre-mRNA splicing. Disclosures Bossard: Biosplice Therapeutics: Current Employment. McMillan: Prizer: Ended employment in the past 24 months. Beaupre: Pfizer: Ended employment in the past 24 months. White: Pfizer: Ended employment in the past 24 months.

Antitumor Effect of Pomolic Acid in Acute Myeloid Leukemia Cells Involves Cell Death, Decreased Cell Growth and Topoisomerases Inhibition

2019 ◽  
Vol 18 (10) ◽  
pp. 1457-1468
Author(s):  
Michelle X.G. Pereira ◽  
Amanda S.O. Hammes ◽  
Flavia C. Vasconcelos ◽  
Aline R. Pozzo ◽  
Thaís H. Pereira ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Acute Myeloid Leukemia ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Natural Compound ◽  
Dna Topoisomerases ◽  
Human Dna ◽  
Pomolic Acid ◽  
Acute Myeloid

Background: Acute myeloid leukemia (AML) represents the largest number of annual deaths from hematologic malignancy. In the United States, it was estimated that 21.380 individuals would be diagnosed with AML and 49.5% of patients would die in 2017. Therefore, the search for novel compounds capable of increasing the overall survival rate to the treatment of AML cells is urgent. Objectives: To investigate the cytotoxicity effect of the natural compound pomolic acid (PA) and to explore the mechanism of action of PA in AML cell lines with different phenotypes. Methods: Three different AML cell lines, HL60, U937 and Kasumi-1 cells with different mechanisms of resistance were used to analyze the effect of PA on the cell cycle progression, on DNA intercalation and on human DNA topoisomerases (hTopo I and IIα) in vitro studies. Theoretical experiments of the inhibition of hTopo I and IIα were done to explore the binding modes of PA. Results: PA reduced cell viability, induced cell death, increased sub-G0/G1 accumulation and activated caspases pathway in all cell lines, altered the cell cycle distribution and inhibited the catalytic activity of both human DNA topoisomerases. Conclusion: Finally, this study showed that PA has powerful antitumor activity against AML cells, suggesting that this natural compound might be a potent antineoplastic agent to improve the treatment scheme of this neoplasm.

scholarly journals The characteristics of circRNA as competing endogenous RNA in pathogenesis of acute myeloid leukemia

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Siyuan Zhang
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Expression Profiles ◽  
Gene Expression Omnibus ◽  
The Novel ◽  
Competing Endogenous Rna ◽  
Regulatory Modules ◽  
Cerna Network ◽  
Regulatory Module ◽  
Acute Myeloid

Abstract Background As one of the novel molecules, circRNA has been identified closely involved in the pathogenesis of many diseases. However, the function of circRNA in acute myeloid leukemia (AML) still remains unknown. Methods In the current study, the RNA expression profiles were obtained from Gene Expression Omnibus (GEO) datasets. The differentially expressed RNAs were identified using R software and the competing endogenous RNA (ceRNA) network was constructed using Cytoscape. Functional and pathway enrichment analyses were performed to identify the candidate circRNA-mediated aberrant signaling pathways. The hub genes were identified by MCODE and CytoHubba plugins of Cytoscape, and then a subnetwork regulatory module was established. Results A total of 27 circRNA-miRNA pairs and 208 miRNA-mRNA pairs, including 12 circRNAs, 24 miRNAs and 112 mRNAs were included in the ceRNA network. Subsequently, a subnetwork, including 4 circRNAs, 5 miRNAs and 6 mRNAs, was established based on related circRNA-miRNA-mRNA regulatory modules. Conclusions In summary, this work analyzes the characteristics of circRNA as competing endogenous RNA in AML pathogenesis, which would provide hints for developing novel prognostic, diagnostic and therapeutic strategy for AML.

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