A Novel Path for ATRA Differentiation Therapy in Acute Myeloid Leukemia with Isocitrate Dehydrogenase Mutations

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3727-3727
Author(s):  
Jean-Emmanuel Sarry ◽  
Helena Boutzen ◽  
Christian Récher
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Negative Regulator ◽  
Granulocytic Differentiation ◽  
Induced Differentiation ◽  
Idh1 R132h ◽  
Recurrent Mutations ◽  
Idh Mutations ◽  
Acute Myeloid

Abstract Acute myeloid leukemia (AML) is characterized by accumulation of malignant blasts with impaired differentiation programs due to recurrent mutations, among which IDH mutations occur in 15% of AML patients. These mutations lead to a block in erythroid commitment while they may also bias hematopoietic differentiation to myeloid lineage. Interestingly, Lyn tyrosine kinase is required for erythroid differentiation and we have observed a reduction of Lyn expression in the presence of IDH1-R132H mutation. It is also a negative regulator of ATRA-induced granulocytic differentiation. Accordingly, we hypothesized that IDH mutations may sensitize AML cells to ATRA-induced differentiation. Here, we report that clinically achievable doses of ATRA are sufficient to trigger differentiation specifically on AML cell lines, primary patient samples and xenograft mice models carrying IDH1 mutation as observed by an increase in CD11b expression, granulocytic enzyme activity and morphologic changes in May-Grunwald-Giemsa staining. We also showed that ATRA-induced terminal granulocytic differentiation increases apoptosis while decreases proliferation and colony formation specifically in IDH1 mutant cells. Moreover, inhibition of IDH1-R132H activity reduced ATRA-sensitivity while increasing expression of IDH mutation correlated with highest ATRA sensitivity. Furthermore, treatment with a cell-permeable form of the oncometabolite specifically produced by the mutant (eg. 2-HydroxyGlutarate) sensitized AML cells to ATRA-induced differentiation. Finally, because ATRA-induced differentiation triggers a transient increase of Lyn activation, its association with Lyn inhibitors synergistically increased ATRA-induced differentiation of IDH mutant blasts. In summary, our results showed that IDH mutations by producing 2-HG sensitized leukemic blasts to ATRA and that this synergizes with Lyn inhibition. Since 2HG concentration reaches millimolar in AML patient serum and is 100-fold higher in IDH mutated patients than in non-mutated ones, we would predict a strong efficacy and specificity of ATRA. Furthermore, as IDH mutations are systematically conserved at relapse, this therapeutic strategy might be promising to achieve a long-term remission specifically for this AML patient subgroup. Disclosures No relevant conflicts of interest to declare.

TIM-3 Is Highly Expressed On Blast Cells In Patients With Acute Myeloid Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4931-4931
Author(s):  
Caixia Li ◽  
Xiao Yu ◽  
Yibei Zhu ◽  
Xiaojin Wu ◽  
Xiao Ma ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Peripheral Blood ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Univariate Analysis ◽  
Negative Regulator ◽  
Clinical Implications ◽  
Potential Marker ◽  
Blast Cells ◽  
Acute Myeloid

Abstract T cell immunoglobulin-3(TIM-3) is known as a negative regulator in anti-tumor immunity through its reaction with TIM-3 ligand, galectin-9. It has been confirmed that TIM-3 is expressed on Th1 cells, dendritic cells, monocytes, macrophages, malignant stem cells and so on. But the expression of TIM-3 and its clinical implications in patients with acute myeloid leukemia(AML) remains unknown. In this study, we sought to determine the expression and clinical implications of TIM-3 in AML. From August 2012 to June 2013, in total of 32 AML patients with sixteen male and sixteen female were enrolled in this study. We collected their peripheral blood before they received any treatment and then obtained their peripheral blood mononuclear cells(PBMC). Monoclonal antibody was added into PBMC and cell population was analyzed by flow cytometry. Blast cells were identified with SSC CD45±and mature lymphocytes with SSC CD45+. The average expression of TIM-3 on blast cells was 43.46%, while on mature lymphocytes was 13.78% (P<0.001). In univariate analysis, the level of expression was not correlated to the percentage of blast cells and there was no difference between each type of AML. Complete remission was similar between different levels of TIM-3 expression(P>0.05). These results demonstrated that TIM-3 was highly expressed on blast cells than on mature cells in AML, which indicated that TIM-3 could be associated with the differentiation of blast cells and a potential marker to detect the tendency of relapse. TIM-3-targeted antitumor therapy presents a perspective possibility. Disclosures: No relevant conflicts of interest to declare.

C/EBPα-Induced MicroRNA 30c Inactivates Notch1 During Granulopoiesis and Is Downregulated In Acute Myeloid Leukemia

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2368-2368
Author(s):  
Christiane Katzerke ◽  
Vikas Madan ◽  
Dennis Gerloff ◽  
Daniela Braeuer-Hartmann ◽  
Jens-Uwe Hartmann ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Bone Marrow Cells ◽  
Conflicts Of Interest ◽  
Mrna Level ◽  
Granulocytic Differentiation ◽  
Hematopoietic Stem ◽  
Knock Out ◽  
Human Cd34 ◽  
Acute Myeloid

Abstract Abstract 2368 The transcription factor CCAAT Enhancer Binding Protein alpha (C/EBPα) is crucial for normal granulopoiesis and frequently disrupted in acute myeloid leukemia (AML). Loss of expression or function of C/EBPα leads to a block of myeloid differentiation. MicroRNAs inhibiting translation of mRNA into protein were identified as critical players in stem cell development. We and others have already shown that C/EBPα exerts its effects by regulating microRNAs such as miR-223 and miR-34a. In a global microRNA-array screen we found miR-30c as a novel target of C/EBPα during granulocytic differentiation. Wild-type C/EBPα-p42 upregulates miR-30c expression, whereas the C/EBPα-p30 mutant, found in AML, does not. Furthermore, G-CSF upregulates miR-30c expression during granulocytic differentiation of primary human CD34-positive progenitor cells. C/EBPα induces miR-30c and downregulates Notch1, a putative target of miR-30c, on protein, but not mRNA level. A block of miR-30c by LNAs prevents C/EBPα–induced downregulation of Notch1 protein expression. miR-30c is a tumor suppressor and downregulated in various subtypes of AML. In mice, miR-30c shows a high expression in LSK (including hematopoietic stem cells), GMP (granulocytic monocytic precursors) and granulocytes. An induced knock-out of C/EBPα in mice leads to a significantly downregulation of miR-30c expression in bone marrow cells. Our data indicates that C/EBPα-induced miR-30c inactivates Notch1 during granulopoiesis and is downregulated in AML. These data reveal the importance of deregulated microRNA expression in leukemia and may provide novel biomarkers and therapeutic targets in AML. Disclosures: No relevant conflicts of interest to declare.

Whole-Exome Resequencing Identifies Somatic Mutations Of BCOR and BCORL1 Transcriptional Corepressor Genes and Major Cohesin Complex Component Genes In Pediatric Acute Myeloid Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 834-834
Author(s):  
Norio Shiba ◽  
Kenichi Yoshida ◽  
Yasunobu Nagata ◽  
Ayana Kon ◽  
Yusuke Okuno ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Somatic Mutations ◽  
Conflicts Of Interest ◽  
Gene Mutations ◽  
Transcriptional Corepressor ◽  
Whole Exome ◽  
Recurrent Mutations ◽  
Pediatric Aml ◽  
Acute Myeloid

Abstract Background Acute myeloid leukemia (AML) is a molecularly and clinically heterogeneous disease. Currently, targeted sequencing efforts have identified several mutations that carry diagnostic and prognostic information such as RAS, KIT, and FLT3 in both adult and pediatric AML, and NPM1 and TET2 in adult AML. Meanwhile, the recent development of massively parallel sequencing technologies has provided a new opportunity to discover genetic changes across the entire genomes or protein-coding sequences in human cancers at a single-nucleotide level, which could be enabled the discovery of recurrent mutations in IDH1/2, and DNMT3A in adult AML. However, these mutations are extremely rare in pediatric AML. Methods To reveal a complete registry of gene mutations and other genetic lesions, whole-exome resequencing of paired tumor-normal DNA from 19 cases were analyzed with a mean coverage of approximately x100, and 82 % of the target sequences were analyzed at more than x20 depth on average. We selected various cases in age, FAB classification and karyotypes, including 5 cases with core-binding-factor AML, 6 cases with MLL-rearrangement and 2 acute megakaryoblastic leukemia cases. Results and Discussion A total of 80 somatic mutations or 4.2 mutations per sample were identified. As the mean number of somatic mutations reported in adult AML was about ten, somatic mutations in pediatric AML might be fewer than in adult AML. Many of the recurrent mutations identified in this study involved previously reported targets in AML, such as FLT3, CEBPA, KIT, CBL, NRAS, WT1 and EZH2. On the other hand, several genes were newly identified in the current study, including BRAF, BCORL1, DAZAP1, CUL2, ASXL2, MLL2, MLL3, SMC3 and RAD21. Among these, what immediately drew our attention were SMC3 and RAD21, because they belong to the major cohesin components. Cohesin is a multimeric protein complex conserved across species and composed of four core subunits, i.e., SMC1, SMC3, RAD21, and STAG proteins, forming a ring-like structure. Cohesin is engaged in cohesion of sister chromatids during cell division, post-replicative DNA repair, and regulation of global gene expression through long-range cis-interactions. Furthermore, we also drew our attention to BCORL1, because it is a transcriptional corepressor, and can bind to class II histone deacetyllases (HDAC4, HDAC5, HDAC7), to interact with the CTBP1 corepressor, and to affect the repression of E-cadherin. BCOR is also a transcriptional corepressor and play a key role in the regulation of early embryonic development, mesenchymal stem cell function and hematopoiesis. To confirm and extend the initial findings in the whole-exome sequencing, we studied mutations of the above 8 genes, in pediatric AML (N = 190) using a high-throughput mutation screen of pooled DNA followed by confirmation/ identification of candidate mutations. In total, 32 mutations were identified in 31 of the 190 specimens of pediatric AML [BCOR (N = 7), BCORL1 (N = 7), RAD21 (N = 7), SMC3 (N = 5), SMC1A (N = 1), and STAG2 (N = 3)]. The mutually exclusive pattern of the mutations in these BCOR, BCORL1 and cohesin components genes was confirmed in this large case series, suggesting a common impact of these mutations on the pathogenesis of pediatric AML. The 4-year overall survival of these cases with major cohesin components gene mutations was relatively favorable (12/16 or 75.0%), but the outcome of cases with BCOR or BCORL1 cases was unfavorable (8/14 or 57.1%). Conclusion Whole exome resequencing unmasked a complexity of gene mutations in pediatric AML genomes. Our results indicated that a subset of pediatric AML represents a discrete entity that could be discriminated from the adult counterpart, in terms of the spectrum of gene mutations. Disclosures: No relevant conflicts of interest to declare.

Aberrant 5-Hydroxymethylcytosine Levels Correlate With Poor Overall Survival In Acute Myeloid Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1261-1261 ◽  
Author(s):  
Leonie I Kroeze ◽  
Mariam G Aslanyan ◽  
Arno van Rooij ◽  
Theresia N Koorenhof-Scheele ◽  
Marion Massop ◽  
...  
Keyword(s):  
Overall Survival ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Response To Therapy ◽  
Leukemic Cells ◽  
Mutational Status ◽  
Idh Mutations ◽  
Very High ◽  
Acute Myeloid

Abstract Background Patients with acute myeloid leukemia (AML) frequently harbor mutations in genes involved in the DNA (hydroxy)methylation pathway (DNMT3A, TET2, IDH1, and IDH2). In addition, changes in DNA methylation have been implicated in the pathogenesis of AML. Recently it was discovered that TET proteins are able to convert 5-methylcytosine into 5-hydroxymethylcytosine (5hmC), which is an important intermediate in the demethylation pathway. In this study, we measured 5-hydroxymethylcytosine levels in AML patients, and correlated these with mutational status and overall survival (OS). Patients and methods Samples from 206 clinically and molecularly well-characterized younger adult AML patients (≤60 years), included in the EORTC/GIMEMA AML-12 06991 clinical trial, were analyzed for mutations in DNMT3A, TET2, IDH1 and IDH2. 5-hydroxymethylcytosine levels were measured using HPLC-MS/MS. Results In healthy control cells, 5hmC levels were confined to a narrow range (1.5 fold difference), whereas in AML cells, a much wider range was detected (15 fold difference). In remission, 5hmC values were normalized to levels comparable to healthy bone marrow and peripheral blood, indicating that the aberrant 5hmC levels at diagnosis are intrinsic to the leukemic cells. Patients with mutations in TET2 and patients with mutations in IDH1/2 had significantly lower levels of 5hmC compared to patients without mutated TET2 and IDH1/2 (both P<.001), whereas mutations in DNMT3A did not influence 5hmC levels. Patients with bi-allelic TET2 inactivation displayed lower 5hmC levels than patients with one affected allele (P=.003). Among the patients that did not harbor TET2 or IDH mutations, still a wide variation in 5hmC levels was observed, and importantly, both low and very high 5hmC levels correlated with inferior OS (P=.02, HR=1.80 and P=.04, HR=1.97, respectively). Multivariate analysis revealed that abnormal levels of 5hmC were independent prognostic indicators for OS. The difference in OS could not be explained by an initial inferior response to therapy, however, the relapse rate was considerably higher in patients with low and very high 5hmC levels compared to patients with intermediate 5hmC. Conclusion Both low and very high levels of 5hmC are markers of poor prognosis in AML, lending further support for testing therapies targeting the DNA hydroxymethylation pathway. Disclosures: No relevant conflicts of interest to declare.

The Combination of ATRA and Dasatinib for Differentiation Therapy in Acute Myeloid Leukemias with IDH Mutations

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2542-2542 ◽  
Author(s):  
Helena Boutzen ◽  
Estelle Saland ◽  
Mathilde Cathebras ◽  
Clément Larrue ◽  
Thomas Farge ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Research Funding ◽  
Leukemic Cells ◽  
Granulocytic Differentiation ◽  
Advisory Committees ◽  
Idh1 R132h ◽  
Recurrent Mutations ◽  
Idh Mutations ◽  
R132h Mutation ◽  
Acute Myeloid

Abstract Acute myeloid leukemia (AML) is characterized by the accumulation of malignant blasts with impaired differentiation programs due to recurrent mutations, amongst which IDH mutations occur in 15% of AML patients. Here, we show both in vitro as well as in a xenografted mouse model, that clinically achievable doses of ATRA are sufficient to achieve a terminal granulocytic differentiation in primary AML samples and in AML cell lines harboring IDH1-R132H mutation. There is no effect at this concentration on the WT controls. This is associated with reduction of both proliferation and colony formation, and further leads to apoptosis, thereby improving overall survival of mutant xenografted mice. We further showed, through transcriptomic and western blot analysis, that specific ATRA sensitivity is due to overexpression and activation of C/EBPα in the presence of IDH1-R132H mutation. This primes blasts into myeloid differentiation. Moreover, IDH1 R132H mutation also reduces LYN activation, and thus, also sensitizes to clinically achievable doses of dasatinib, a LYN inhibitor. As ATRA induces a brief LYN activation, which transiently reduces ATRA activity, its combination with dasatinib synergistically increases differentiation. In vivo, the combination of ATRA and dasatinib reduces tumor growth of mutant xenografted mice. The combination ATRA and dasatinib might also be considered for other IDH mutations that produce 2-hydroxyglutarate, since treatment with the mutant-specific oncometabolite (eg. 2-hydroxyglutarate) sensitizes AML cells to ATRA and dasatinib-induced differentiation. Finally, ATRA also reduces BCL2 expression specifically in the presence of IDH1 R132H mutation. Since it has been shown that IDH mutations increase BCL2 dependence in leukemic cells, our results identified a subgroup of patients that is likely to respond to pharmacologic concentrations of ATRA. To conclude, our data provide the preclinical rationale for investigating the use of the combination ATRA and dasatinib in a subgroup of patients who carry IDH1 R132H mutation, in clinical trials. The addition of a BCL2 inhibitor such as ABT-199 would also be considered. Disclosures Off Label Use: ATRA and dasatinib for treatment of non APL AML. Recher:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sunesis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Chugai: Research Funding.

scholarly journals The role of enasidenib in the treatment of mutant IDH2 acute myeloid leukemia

2018 ◽  
Vol 9 (7) ◽  
pp. 163-173 ◽  
Author(s):  
Iman Abou Dalle ◽  
Courtney D. DiNardo
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Single Agent ◽  
The United States ◽  
Dna Hypermethylation ◽  
Induced Differentiation ◽  
Recurrent Mutations ◽  
Isocitrate Dehydrogenase 2 ◽  
Differentiation Block ◽  
Acute Myeloid

Recurrent mutations affecting cellular metabolism and epigenetic regulation are implicated in the pathogenesis of acute myeloid leukemia (AML). Isocitrate dehydrogenase 2 ( IDH2) gene mutations are described in 12% of patients with AML and 5% of patients with myelodysplastic syndromes. IDH2 enzyme is involved in the Krebs cycle, catalyzing α-ketoglutarate from isocitrate. Mutant IDH2 enzymes acquire a neomorphic enzymatic activity with the ability to produce 2-hydroxyglutarate from α-ketoglutarate, inhibiting multiple α-ketoglutarate-dependent dioxygenase reactions; leading to aberrant DNA hypermethylation and differentiation block in myeloid precursors and ultimately promoting leukemogenesis. Enasidenib (formerly AG-221) is an oral small molecule selective targeted inhibitor of the mutant IDH2 enzyme, approved in August 2017 by the United States Food and Drug Administration for the treatment of patients with relapsed or refractory (R/R) IDH2-mutated AML. Preclinical studies showed the effectiveness of enasidenib in inhibiting the production of 2-hydroxyglutarate with high potency, and alleviating the mutant IDH2-induced differentiation block. In the original AG221-001 phase I/II trial, patients with R/R AML were treated with enasidenib single agent therapy at escalating doses up to 650 mg daily, with the 100 mg dose level identified to be safe and effective for further evaluation. Overall, 113 patients were treated in the dose-escalation and 126 in the dose-expansion cohorts. The overall response rate for R/R patients was 40%, including a complete remission of 19%. At a median follow up of 7.7 months, the median overall survival was 9.3 months, and reached 19.7 months in responders. Enasidenib was well tolerated, although adverse events of clinical interest include indirect hyperbilirubinemia and IDH-inhibitor-induced differentiation syndrome, which can be life threatening if not identified and treated promptly. Ongoing clinical trials evaluating enasidenib in combination with intensive chemotherapy and hypomethylating agents in newly diagnosed AML, and in rational combinations for R/R AML patients are underway.

scholarly journals Isocitrate dehydrogenase inhibitors in acute myeloid leukemia

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Xiaoyan Liu ◽  
Yuping Gong
Keyword(s):  
Acute Myeloid Leukemia ◽  
Isocitrate Dehydrogenase ◽  
Myeloid Leukemia ◽  
Acquired Resistance ◽  
Tca Cycle ◽  
Idh Mutation ◽  
Hematopoietic Stem ◽  
Idh Mutations ◽  
Key Enzyme ◽  
Acute Myeloid

Abstract Isocitrate dehydrogenase (IDH) is a key enzyme involved in the conversion of isocitrate to α-ketoglutarate (α-KG) in the tricarboxylic acid (TCA) cycle. IDH mutation produces a neomorphic enzyme, which can lead to the abnormal accumulation of R-2-HG and promotes leukemogenesis. IDH mutation occurs in 20% of acute myeloid leukemia (AML) patients, mainly including IDH1 R132, IDH2 R140, and IDH2 R172. Different mutant isoforms have different prognostic values. In recent years, IDH inhibitors have shown good clinical response in AML patients. Hence, enasidenib and ivosidenib, the IDH2 and IDH1 inhibitors developed by Agios Pharmaceuticals, have been approved by the Food and Drug Administration on 1 August 2017 and 20 July 2018 for the treatment of adult relapsed or refractory (R/R) AML with IDH2 and IDH1 mutations, respectively. IDH inhibitor monotherapy for R/R AML is efficacious and safe; however, there are problems, such as primary or acquired resistance. Clinical trials of IDH inhibitors combined with hypomethylating agents or standard chemotherapy for the treatment of R/R AML or newly diagnosed AML, as well as in post hematopoietic stem cell transplantation as maintenance therapy, are ongoing. This article summarizes the use of IDH inhibitors in AML with IDH mutations.

Clinical characteristics and outcomes in patients with acute myeloid leukemia with concurrent FLT3 ‐ITD and IDH mutations

Cancer ◽  
2020 ◽  
Author(s):  
Mahran Shoukier ◽  
Tapan Kadia ◽  
Marina Konopleva ◽  
Ahmad S. Alotaibi ◽  
Mansour Alfayez ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Clinical Characteristics ◽  
Idh Mutations ◽  
Acute Myeloid

Rig-I Activates Expression of Interferon-Stimulated Genes (ISGs) and Inhibits the Proliferation of Acute Myeloid Leukemia Cells

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2846-2846 ◽  
Author(s):  
Nan-Nan Zhang ◽  
Lei Chen ◽  
Wu Zhang ◽  
Xian-Yang Li ◽  
Lin-Jia Jiang ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Leukemia Cells ◽  
Mrna Levels ◽  
Terminal Part ◽  
Granulocytic Differentiation ◽  
Acute Myeloid Leukemia Cells ◽  
Acute Myeloid

Abstract Acute promyelocytic leukemia (APL) is initiated by the formation of PML/RARα oncogenic fusion protein, a potent transcriptional repressor. Retinoid acid (RA) at pharmacological dosage can physically bind to the PML/RARα protein, ushering in the unfolding of downstream programs normally regulated by the wild type RARα. However, through what particular regulatory pathways RA inhibits APL malignant hematopoiesis has remained largely obscured. Rig-I is one of the genes whose mRNA levels were highly up-regulated, along with all-trans-RA (ATRA)-induced terminal granulocytic differentiation of APL cell line NB4 cells in vitro. Based on the analysis of a Rig-I−/− mouse model, recently we have reported a critical regulatory role of Rig-I in normal granulopoiesis. To understand the functional contribution of Rig-I induction in RA-mediated leukemia cell differentiation, we converted a pair of previously reported Rig-I RNAi-duplex sequences into a miR30a-based small hairpin-encoding sequence, which was expressed under the CMV enhancer/promoter within a lentiviral vector. As expected, Rig-I shRNAmir30 infection induced a significant knockdown of Rig-I protein level, and accordingly its delivery into HL-60 cells partially inhibited ATRA-induced granulocytic differentiation, growth inhibition/cell cycle arrest and apoptosis induction, suggesting that Rig-I upregulation participates in RA-induced granulocytic differentiation of acute myeloid leukemia cells. In order to investigate the effect of Rig-I induction on the proliferation of APL cells in vivo, we transduced PML/RARα-harboring leukemic cells with vector or Rig-I-expressing retrovirus, and then transplanted these cells into the syngeneic mice. The vector-transduced APL cells readily expanded in vivo, but the proliferation of Rig-I-transduced cells was apparently prohibited. Moreover, we found that the forced expression of Rig-I induced the expression of numerous ISGs in APL cells, which was recapitulated by the transduction of the C terminal part of Rig-I, but not by the N terminal part. In line with this, during the in vitro short-term culture post-IFNγ or IFNα stimulation, Stat1 phosphorylation at p701 in Rig-I−/− granulocytes was significantly inhibited. In parallel, the induction of multiple ISGs by IFNs was also significantly impaired. In conclusion, our findings indicate that the Rig-I induction inhibited APL reconstitution potentially through up-regulating a number of ISGs via regulating Stat1Tyr701 phosphorylation.

The Use of Purine Analogues Does Not Aggravate Infectious Complications During Induction and Consolidation Therapy of Acute Myeloid Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1011-1011
Author(s):  
Marek Seweryn ◽  
Jerzy Wojnar ◽  
Dariusz Kata ◽  
Slawomira Kyrcz-Krzemien
Keyword(s):  
Acute Myeloid Leukemia ◽  
Induction Therapy ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Infectious Complications ◽  
Induction Treatment ◽  
High Dose ◽  
Consolidation Therapy ◽  
Purine Analogues ◽  
Acute Myeloid

Abstract Abstract 1011 Poster Board I-33 Background: Addition of purine analogues to standard induction therapy of acute myeloid leukemia (AML) had previously been demonstrated to increase complete remission rate. The aim of this study was to analyze whether the use of cladribine or fludarabine during induction and consolidation increases the risk of infectious complications. Material and methods: 118 AML patients, included in two consecutive randomized trials between 1999-2006 in a single centre were analyzed. Induction therapy consisted of daunorubicin + cytarabine (DA-7, n=53) alone or in combination with cladribine or fludarabine (DAC-7 + DAF-7, n=65 ). Consolidation included one course of high-dose AraC + mitoxantrone and one course of high-dose AraC +/- purine analogues. A median age was 45(17-58) years and 48(20-60) years for patients treated with and without purine analogues, respectively. Results: The frequency of neutropenic fever as well as microbiologically documented bacterial, fungal and viral infections during induction and consolidation did not differ between two compared groups - receiving or not purine analogues. Time to infection occurrence and infection duration were similar in both study groups. During induction and both consolidation treatments significant lower values of lymphocytosis were observed in the group of patients treated with purine analogues. There was a slight tendency to increased rate of mucositis for patients treated with purine analogues (60% vs. 44.3%, p=0.07) during induction treatment, while infections affecting skin and soft tissues were significant frequent for patients treated without purine analogues (43.3% vs. 18%, p=0.03) during second consolidation treatment (high dose AraC). The usage of intravenous anti-infectious medications (antibiotics, antifungal, antiviral) and periods of hospitalization did not differ between two groups in this study. Conclusions: We conclude that the use of purine analogues, either cladribine or fludarabine along with conventional induction and consolidation therapy does not aggreviate infectious complications in adults with AML. Disclosures: No relevant conflicts of interest to declare.

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