scholarly journals Differences Between CEBPA bZIP and TAD Mutations and Their Effect on Outcome-an Analysis in 4578 Patients with Acute Myeloid Leukemia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 283-283 ◽  
Author(s):  
Julia-Annabell Georgi ◽  
Franziska Taube ◽  
Michael Kramer ◽  
Sylvia Herold ◽  
Kerstin Schaefer-Eckart ◽  
...  

Abstract Mutations of the key myeloid transcription factor CCAAT/enhancer binding protein alpha (C/EBPa) are found in 5-10% of patients with acute myeloid leukemia (AML). Two mutational clusters exist, in the aminoterminal transcription activation domains (TAD1 or 2) and in the basic leucine zipper domain (bZIP) located at the carboxyterminal-part of the protein. Biallelic mutations (biCEBPA) have been found to be associated with improved outcome and are now included as an independent entity in the WHO-classification. In contrast, monoallelic CEBPA-mutations (moCEBPA) do not appear to provide prognostic information. We characterized a large cohort of AML patients for CEBPA mutations and further analyzed the mutational spectrum of mono- and biallelic CEBPA-mutant AML patients to better understand potential differences in the biology of these groups. Patients and Methods: Patients (including all age groups) analyzed had a newly diagnosed AML and were registered in clinical protocols of the Study Alliance Leukemia (SAL)(AML96, AML2003 or AML60+, SORAML) or the SAL-register. Screening for CEBPA mutations was done using PCR and capillary electrophoresis. All identified CEBPA mutations were confirmed using conventional Sanger sequencing and the samples were further analyzed using next generation sequencing (Trusight Myeloid Panel, Illumina) for the presence of associated alterations. Results: In the 4578 patients analyzed, 228 (5%) with CEBPA-mutations were identified. An initial analysis revealed substantial clinical differences between the different mutation subtypes. Patients with biCEBPA (n=111) were significantly younger (median age 46 yrs) than wt-CEBPA patients (median 57 yrs; p<.001). Interestingly, single bZIP mutant patients (n=64) had a similar median age (50 yrs.) as biCEBPA, whereas single TAD mutant patients (n=53) were significantly older (median 63 yrs.). In addition, WBC counts, CD34 positivity as well as the history of prior MDS differed between the subgroups (single TAD mutant had significantly lower WBC counts, lower rate of CD34 positivity and had a higher rate of prior MDS than biCEBPA and single bZIP mutant patients). Along with this, the distribution of co-mutations differed significantly between the subgroups, especially GATA2 mutations were more common in biCEBPA and single bZIP mutant patients (37% and 34%, respectively) compared to only 3% (single TAD)(p=.001). A similar pattern was seen for mutations in DNMT3A (8% biCEBPA, 20% single bZIP vs. 36% single TAD; p=.001), and NPM1 (3% biCEBPA, 8% single bZIP, 32% single TAD; p<.001). In 2897 patients, the different CEBPA mutations were correlated with outcome. This analysis indicated a differential effect of the individual mutations on outcome, with an improved rate of complete remission (CR), overall survival (OS) and event free survival (EFS) for biCEBPA and single bZIP mutations in univariate and multivariate analyses (shown for OS in Figure 1a). Given the similarity of single bZIP and biCEBPA mutations, it appears reasonable to speculate on a common mechanistical background, since most of the biCEBPA mutants include a bZIP alteration. Recent experimental evidence generated by several groups indeed supports a specific role of these bZIP missense mutations. To address this in the clinical context, we regrouped patients with mutant CEBPA into patients with (n=157) or without bZIP mutations (n=71), irrespective of the biallelic status. As illustrated in Figure 1b, the bZIP mutant group had a significantly better OS, similar results were obtained for EFS and CR. In multivariate analysis, the presence of a bZIP mutation was the strongest indicator for achievement of CR (HR 7.5, 95% CI: 3-19; p<.001), and together with favorable cytogenetics the factor associated with best OS (HR: .48; 95% CI .36-.64; p<.001). In conclusion, our results obtained in one of the largest cohorts of AML patients analyzed for CEBPA mutations indicate that especially the presence of a missense bZIP mutation is associated with a favorable outcome in AML patients. These data point to substantial differences in prognostic implications of individual CEBPA mutations and support the major functional divergence of these alterations. If confirmed, these results might necessitate further refinement of their use in AML-classification. Disclosures Middeke: Sanofi: Honoraria. Platzbecker:Janssen-Cilag: Honoraria, Research Funding; Celgene Corporation: Honoraria, Research Funding; TEVA Pharmaceutical Industries: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Thiede:AgenDix: Employment, Other: Ownership.

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 72-72 ◽  
Author(s):  
Annika Dufour ◽  
Nikola Konstandin ◽  
Bianka Ksienzyk ◽  
Evelyn Zellmeier ◽  
Tobias Benthaus ◽  
...  

Abstract Abstract 72 Cytogenetically normal acute myeloid leukemia (CN-AML) with biallelic CEBPA gene mutations (biCEPBA) represents a distinct genetic entity associated with a favorable clinical outcome (Dufour et al, JCO, 2010; Green et al, JCO, 2010; Pabst et al, Br J Cancer, 2009; Wouters et al, Blood, 2009). Furthermore, biCEBPA mutations are seldomly associated with other known prognostic mutations, like mutated NPM1 or FLT3-ITD. So far, it is not known if other alterations cooperate with the biCEBPA mutations in the process of leukemogenesis. To identify collaborating mutations, we performed whole exome sequencing in five biCEBPA mutated CN-AML patients. We generated at least 5 Gbp of exome sequence for each of the biCEBPA AML samples and for the corresponding remission samples. This allowed us to cover at least 80% of RefSeq coding exon positions with a minimum read depth of 10. Comparison of the AML exome sequence with the remission exome sequence and exclusion of annotated polymorphisms led to the identification of leukemia-specific variants. So far, we were able to confirm between 2 to 10 non-synonymous coding somatic mutations per patient in addition to the previously known biCEBPA mutations using Sanger sequencing. Thus, we detected tumor-specific mutations (nonsense and missense) in a total of 22 genes. Two genes were found recurrently mutated in 2 of the 5 biCEBPA samples: DNMT3A (2/5) and GATA2 (2/5). GATA2 is a zinc finger transcription factor important for haematopoietic stem cell proliferation and normal megakaryocytic development. GATA2 mutations have recently been associated with familial monocytopenia and familial myelodysplastic syndrome (Hsu et al, Blood, 2011; Scott et al, ASH abstract 2010). In the M5 subtype of AML, GATA2 mutations were found at a low frequency of 3.6% (Yan et al, Nature Genetics, 2011). Interestingly, GATA2 is a direct protein interactor and negative regulator of CEBPA. (Huang et al., MCB, 2009; Tong et al, MCB, 2005). Therefore, we determined the frequency of GATA2 mutations in 32 patients with biCEBPA mutant AML by screening all coding exons of GATA2 using high resolution melting curve analysis. Aberrant melting curves were subsequently confirmed by Sanger sequencing. Interestingly, 13 out of 32 (40.6%) biCEBPA patients carried heterozygous missense mutations in GATA2 and strikingly these mutations were all located in the highly conserved N-terminal zinc finger domain of GATA2. The missense mutations A318T and G320D surrounding the C319 which coordiates the zinc atom were recurrently detected in 6 out of 13 biCEBPA patients (3 with A318T and 3 with G320D). Two patients were found to carry each two different mutations in GATA2. 4 out of 13 biCEBPA patients with GATA2 mutations who could be analyzed during molecular remission had lost the GATA2 mutation at remisssion. Furthermore, no GATA2 mutations were found in 38 patients with a monoallelic CEBPA mutation and in 90 CN-AML patients with wildtype CEBPA. We are currently analyzing the functional consequences of these GATA2 mutations. In summary, we describe for the first time the specific association of mutations within the N-terminal zinc finger of GATA2 with biallelic CEBPA mutations in cytogenetically normal AML. Although high throughput sequencing so far has mainly revealed an increasing genetic heterogeneity in AML, our results suggest that there is an association of distinct mutations in defined genetic subgroups of AML. Disclosures: Krebs: Illumina: Honoraria. Greif:Illumina: Honoraria.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 32-33
Author(s):  
Kotoko Yamatani ◽  
Tomohiko Ai ◽  
Kaori Saito ◽  
Haeun Yang ◽  
Vivian Ruvolo ◽  
...  

Internal tandem duplications in the juxtamembrane domain of FMS-like tyrosine kinase 3 gene (FLT3-ITD) and missense mutations in the gene's tyrosine-kinase domain (FLT3-TKD) play critical roles in the pathophysiology of acute myeloid leukemia (AML). Recent study revealed that AML cells resistant to quizartinib, a type II TKI, consist of heterogeneous clonal populations harboring wild-type FLT3 as well as FLT3-ITD, FLT3-TKD and FLT3-ITD/TKD mutations, and on- and off-target mechanisms may contribute to the resistance to TKIs. To overcome the heterogeneous resistance mechanisms of FLT3-ITD and TKD mutations, various combinatorial therapies have been investigated. For example, BCL-2 inhibition in the presence of TKIs increased survival a murine FLT3-ITD AML model, and a phase Ib/II clinical trial of a combination of quizartinib with venetoclax, a BCL2 inhibitor is ongoing in relapsed/refractory FLT3-mutant AML patients (NCT03735875). To dissect underlying mechanisms of drug-resistance and exploring new targets in refractory AML with FLT3-ITD and TKD mutations, we investigated alterations of transcriptome signatures by analyzing AML samples with FLT3-ITD/D835 dual mutations. Previously, we reported BCL2A1 transcriptomes were upregulated in primary AML cells with FLT3-ITD/D835 dual mutations compared to cells with FLT3-ITD mutations only. This was recapitulated in the MV4-11 cells harboring FLT3-ITD/D835 dual mutations after 6 month-exposure to quizartinib. The MV4-11 cells with the FLT3-ITD/D835 dual mutations became resistant to quizartinib, and the cells also became resistant to venetoclax, a BCL2 inhibitor (Yamatani et al. ASH 2019). In this study, we further investigated BCL2A1 as new target in refractory AML with FLT3-ITD/D835 dual mutations. First, we examined whether overexpression of BCL2A1 induces drug-resistance in MV4-11 and Molm13 cell lines with FLT3-ITD. While parental MV4-11 and Molm13 cells are sensitive to venetoclax and quizartinib, MV4-11 and Molm13 cells transfected with lentivirus carrying BCL2A1 became resistant to venetoclax (IC50: MV4-11 with BCL2A1 over-expression &gt;1000 nM vs. mock vector 0.71 nM; Molm13 with over-expression &gt;1000 nM vs. mock vector 0.38 nM, 72h). In contrast, the sensitivity to quizartinib was retained in the BCL2A1 overexpressing MV4-11 and Molm13 cells. These findings indicate that the overexpression of BCL2A1 could play a role in the acquired resistance to venetoclax, but not to quizartinib. Bromodomain-containing protein 4 (BRD4), a family member of bromodomain and extra-terminal motif (BET) is known to transcriptionally modulate BCL2A1 gene expression. Next, we examined effects of CPI-0610, a BET inhibitor, on MV4-11 cells with FLT3-ITD or the FLT3-ITD/D835 dual mutation. CPI-0610 inhibited cell growth of MV4-11 cells by inducing apoptosis irrespective of co-existing FLT3 mutations (IC50: FLT3-ITD/D835, 255 nM vs. FLT3-ITD, 191 nM, 72h). Immunoblotting analyses confirmed that BET inhibition by CPT-0610 decreased the expression of BCL2A1 in MV4-11 cells FLT3-ITD/D835. WIn conclusion, transcriptome analysis and molecular pharmacological approaches identified alterations in the anti-apoptotic BCL2 family proteins in double-mutant FLT3 leukemias. BCL2A1 upregulation might be involved in drug resistance of FLT3-ITD/D835 dual mutant AML cells, and could be a promising new target in refractory AML with FLT3-ITD/D835 dual mutations. Disclosures Konopleva: Cellectis: Research Funding; Eli Lilly: Research Funding; Calithera: Research Funding; Sanofi: Research Funding; Ascentage: Research Funding; AstraZeneca: Research Funding; Agios: Research Funding; Stemline Therapeutics: Consultancy, Research Funding; Kisoji: Consultancy; Genentech: Consultancy, Research Funding; F. Hoffmann La-Roche: Consultancy, Research Funding; Forty-Seven: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Reata Pharmaceutical Inc.;: Patents & Royalties: patents and royalties with patent US 7,795,305 B2 on CDDO-compounds and combination therapies, licensed to Reata Pharmaceutical; Rafael Pharmaceutical: Research Funding; Ablynx: Research Funding; Amgen: Consultancy. Carter:Syndax: Research Funding; AstraZeneca: Research Funding; Amgen: Research Funding; Ascentage: Research Funding. Andreeff:Daiichi-Sankyo; Breast Cancer Research Foundation; CPRIT; NIH/NCI; Amgen; AstraZeneca: Research Funding; Centre for Drug Research & Development; Cancer UK; NCI-CTEP; German Research Council; Leukemia Lymphoma Foundation (LLS); NCI-RDCRN (Rare Disease Clin Network); CLL Founcdation; BioLineRx; SentiBio; Aptose Biosciences, Inc: Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Daiichi-Sankyo; Jazz Pharmaceuticals; Celgene; Amgen; AstraZeneca; 6 Dimensions Capital: Consultancy.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2620-2620 ◽  
Author(s):  
Thomas Guéry ◽  
Christophe Roumier ◽  
Céline Berthon ◽  
Pascale Lepelley ◽  
Aline Renneville ◽  
...  

Abstract Introduction The B7 family of costimulatory molecules comprises several members, such as PD-L1 (B7-H1), that may participate in the immunoescape of tumor cells. For instance, the expression of PD-L1 in cancer cells can induce immunotolerance by deactivating T cells in several hematological malignancies, including acute myeloid leukemia (AML) and MDS. The B7-H3 (B7-homolog 3 or CD276) is a type I transmembrane protein and a member of the B7 family. B7-H3 is expressed in many tissues and in antigen-presenting cells. Its functions and counter receptor(s) remain unclear. The expression of the B7-H3 protein by the tumor microenvironment and tumor cells modifies the antitumor immune reaction, tumor growth, metastatic ability and drug resistance. B7-H3 is widely expressed in solid cancers and seems to be a prognostic marker in several tumor types. Clinical grade anti-B7-H3 antibodies are under development. The role of B7-H3 and its expression in AML has not yet been well investigated. We examined the expression of B7-H3 in the blast cells of a cohort of patients with AML to determine whether its expression affected the patients’ prognoses. Methods Our retrospective study included 111 patients (18 children and 93 adults) treated for AML between 2009 and 2011. We measured B7-H3 expression in bone marrow mononuclear cells using multiparameter flow cytometry (CD56, B7-H3, CD34, CD123, CD14, CD38 and CD45). We investigated the correlation of B7-H3 expression with biological, molecular and cytogenetic markers as well as the patient’s clinical characteristics. FLT3-ITD, NPM1 and CEBPA mutations were screened by the conventional Sanger methodology according to the ELN recommendations. Results B7-H3 expression was low and invariable in lymphocytes and high in monocytes. According to the MFI (Mean Fluorescence Intensity) ratio of blasts/lymphocytes, the B7-H3 expression level in blasts was widely variable (0.80 to 10.38). The threshold retained in our study was 3. Twenty seven percent (30/111) of AML samples were positive, and positive samples primarily included the M5 and M3 FAB subtypes (50% of B7-H3 positive patients). The expression of B7-H3 did not correlate with age (p=0.86), sex (p=0.79), leucocytosis (p=0.38) or NPM1 mutation status (p=0.08). The expression of B7-H3 was significantly higher in adverse karyotypes (p<0.05). The expression of B7-H3 was significantly lower in CEBPA mutations (p<0.05) and tended to be lower in Core Binding Factors AML (p = 0.054). In the 54 adults who were treated with intensive chemotherapy, B7-H3 did not affect the complete remission (CR) rate (81% in B7-H3 negative group, 89% in B7-H3, positive group, p=0.62) or the overall survival (p=0.73). Conclusion B7-H3 is highly expressed in a substantial fraction of AML cases, which suggests that it could serve as a possible therapeutic target. The significant differences in the B7-H3 expression between the different subgroups of AML according to FAB, cytogenetic or CEBPA mutational status should encourage further screening of B7-H3 in a larger prospective cohort of AML patients to obtain definitive conclusions about its prognostic value. Disclosures: Berthon: CELGENE: Research Funding. Preudhomme:CELGENE: Research Funding.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1663-1663
Author(s):  
Sabine Kayser ◽  
Maximilian Feszler ◽  
Julia Krzykalla ◽  
Matthias Schick ◽  
Thomas Hielscher ◽  
...  

Abstract Background:Recent publications suggest important roles of lysine methyltransferase 2C (KMT2C, located on 7q) and sprouty 4 (SPRY4, located on 5q) as candidate genes in leukemogenesis of acute myeloid leukemia (AML). The prognostic impact of the gene expression levels (ELs) of both genes on outcome in AML patients (pts) is currently unclear. Aim:To evaluate the prognostic impact of KMT2C and SPRY4 expression in correlation to clinical characteristics and genetic abnormalities assessed at diagnosis in a cohort of intensively treated adult AML pts. Methods: We retrospectively studied 268 AML pts (median age, 48 years; range, 17-60 years) who had been enrolled on 2 AML SHG trials (0295 and 0199, n=148; only normal cytogenetics pts (CN)) and the SAL-AML2003 trial (n=120; only abnormal cytogenetics pts (CA)). Acute promyelocytic and core-binding factor leukemia pts were excluded. Type of AML was de novo in 235 (88%), secondary in 19 (7%) and therapy-related in 14 (5%) of the 268 pts. Regarding baseline characteristics, CN pts had significantly higher white blood counts (WBC; p=0.001) and blast cells in peripheral blood (p=0.02) as compared to CA pts; all other factors were comparable. Cytogenetic analyses could be performed in 263 (98%) of the 268 pts. Cytogenetic risk classification according to ELN guidelines was intermediate-II in 55 (47%) and adverse in 63 (53%) of the CA pts, respectively. Abnormalities (abn) of 5q were present in 21 (18%) and abn of 7q in 16 (14%) of the CA pts. NPM1 and FLT3-ITD were analyzed in 145 (98%) of the CN pts. Of those, 59 (41%) were only NPM1 positive (pos), 12 (8%) were only FLT3-ITD pos, 34 (23%) were double pos and 40 (28%) were double negative (neg). KMT2C and SPRY4 ELs, normalized to ABL1and log2-transformed for analysis, were measured in triplets on cDNA obtained at diagnosis by RT-qPCR. Based on cDNA availability, KMT2C ELs could be analyzed in 143 (97%) of the CN and in all of the 120 CA pts, respectively. SPRY4 ELs could be measured in 30 (21%) of the CN and 107 (89%) of the CA pts, respectively. Results: KMT2C ELs were significantly lower in CN pts with de novo as compared to secondary AML (p= 0.02), whereas there was no difference in CA pts. No significant association was found for SPRY4 and type of AML. KMT2C ELs were significantly lower in FLT3-ITD pos as compared to FLT3-ITD neg CN pts (p=0.046), whereas there was no difference for SPRY4 ELs between the two groups (p=0.57). In addition, there was a significantly lower KMT2C expression in CN pts with intermediate-I risk as compared to NPM1 pos / FLT3-ITD neg pts (p=0.01). Regarding CA pts, there was no difference of KMT2C or SPRY4 ELs in adverse as compared to intermediate-II risk pts (p=0.08; p=0.20, respectively). When focusing on specific subgroups, KMT2C ELs were significantly lower in abn7q CA pts as compared to those without abn7q (p=0.002), whereas there was no difference of SPRY4 ELs in CA pts with or without abn5q (p=0.27). In univariate analysis higher SPRY4 ELs showed a significant favorable impact on relapse-free (RFS, p=0.03) and a trend towards a beneficial impact on overall survival (OS, p=0.06) for CA patients. A similar effect for KMT2C was not observed (RFS, p=0.96; OS, p=0.92). In subgroup analyses of pts with adverse risk cytogenetics, there was no impact of KMT2C or SPRY4 ELs on RFS (p=0.73; p=0.39) or OS (p=0.49; p=0.46), respectively. The same was true for FLT3-ITD pos CN pts (RFS, p=0.73; p=0.37; OS, p=0.91; p=0.36, respectively). In multivariate analyses on RFS and OS in CA pts including age, gender, KMT2C and SPRY4 ELs, logarithm of WBC, blast cells in bone marrow and cytogenetic risk group as variables, only higher age (OS, Hazard ratio (HR),1.28 per 10 years; 95%-confidence interval (CI): 1.02-1.59; p=0.03) and complex karyotype as compared to intermediate-II risk cytogenetics (RFS, HR: 2.25; 95%-CI: 1.20-4.22; p=0.01; OS, HR: 2.97; 95%-CI: 1.65-5.35; p<0.001) had an adverse impact. An effect of KMT2C or SPRY4 on RFS (p=0.84; p=0.16) or OS (p=0.85; p=0.45) was not found in the multivariate setting. In addition, in a multivariate model on CN pts (risk class according to NPM1 and FLT3-ITD mutational status instead of cytogenetic risk class) neither KMT2C nor SPRY4 had an impact on RFS (p=0.13; p=0.39, respectively) or OS (p=0.36; p=0.56, respectively). Conclusions:Lower KMT2C and SPRY4 ELs are associated with distinct genetic risk groups. An impact on prognosis was evident in univariable analyses for SPRY4 but not for KMT2C ELs in CA pts. Disclosures Kayser: Novartis: Consultancy. Platzbecker:Amgen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; TEVA Pharmaceutical Industries: Honoraria, Research Funding; Janssen-Cilag: Honoraria, Research Funding; Celgene Corporation: Honoraria, Research Funding. Heuser:Tetralogic: Research Funding; Novartis: Consultancy, Research Funding; Celgene: Honoraria; Bayer Pharma AG: Research Funding; Pfizer: Research Funding; Karyopharm Therapeutics Inc: Research Funding; BerGenBio: Research Funding. Thiede:AgenDix: Employment, Other: Ownership.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 163-163 ◽  
Author(s):  
Olivier Nibourel ◽  
Olivier Kosmider ◽  
Meyling Cheok ◽  
Nicolas Boissel ◽  
Aline Renneville ◽  
...  

Abstract Abstract 163 In acute myeloid leukemia (AML), both cytogenetic and molecular abnormalities are strongly associated with prognosis. In particular, in cytogenetically normal AML (CN-AML), FLT3-ITD (internal tandem duplication) carries adverse prognostic factor whereas NPM1 or CEBPA mutations are associated with favorable outcome. Recently, mutations of the ten eleven translocation 2 gene (TET2) have been reported myeloid neoplasms. We evaluated the frequency and prognostic value of TET2 alterations, in a cohort of 111 de novo AML patients. We studied 111 patients aged between 15 years and 69 years with previously untreated de novo AML who had reached complete remission (CR) using intensive chemotherapy. 28 of them also received an allogenic bone marrow transplantation in first CR. Analysis of TET2 sequence variation was performed by direct sequencing of PCR products from 111 genomic DNA samples obtained at diagnosis. Frameshift and nonsense variations were all scored as mutation whereas missense mutations were retained when observed at diagnostic but absent in the CR paired sample obtained. Previously identified single nucleotide polymorphisms (SNP) were not considered. TET2 anomalies were numbered according to Genebank reference FM992369. Paired diagnosis and CR genomic DNAs were analyzed using Affymetrix Genome-Wide Human SNP Array 6.0 (Affymetrix, Santa Clara, CA). Data were analyzed using Gene Chip Genotyping Console 3.0.2 and Partek Genomics Suite (www.partek.com/). Comparisons were made by Fisher's exact test for binary variables and the Mann-Whitney‘s test for continuous variables. Disease Free Survival (DFS) and overall survival (OS) were calculated according to the Kaplan-Meier method. Comparisons regarding DFS and OS were performed with the log-rank test. 24 acquired TET2 mutations were observed in 19 of the 111 (17%) de novo AML patients, suggesting the alteration of the two TET2 alleles in 5 patients. They included 21 different events: 6 frameshift, 7 non-sense and 11 missense mutations. Four of the missense mutations were located in conserved regions and 7 outside. All of them were detected in the diagnostic sample but were absent in the paired remission sample. Except for two missense mutations (S282F, T492S) both detected in two patients, no recurrent TET2 mutation was observed. Acquired mutations were spread over all exons. No case of uniparental disomy (UPD) was observed and only one patient presented a small deletion of 60Kb in the TET2 gene locus without TET2 mutation. No significant difference was observed between patients with or without TET2 alterations for gender, age, hemoglobin level, platelet count, FAB subtypes distribution and cytogenetics according to MRC classification, but there was a trend for higher WBC count in patients with TET2 alteration. No significant association was observed between TET2 mutations and FLT3 or CEBPA alterations. However, TET2 alterations were significantly associated with NPM1 mutations (p=0.032). In the entire patient cohort, no difference in DFS or OS was seen between patients with and without TET2 alteration. However, a significantly worse DFS was observed for patients presenting TET2 mutations within the subgroup of patients with NPM1 mutations (3y-DFS: 0% vs 66.4%, 95% CI [45.6–87.2], p=0.008) Considering both the favorable prognosis of NPM1 mutations without FLT3-ITD in CN-AML and the absence of clear association between FLT3-ITD and TET2 alterations in this study, prognostic value of the genotype characterized by NPM1 mutation without FLT3-ITD or TET2 alteration (NPM1+FLT3-ITD-TET2-) was compared to other patients within CN-AML group (N=54). NPM1+FLT3-ITD-TET2- patients showed a significantly better DFS and OS compared to other patients in CN-AML group (3y-DFS: 82.1%, 95% CI [59.1–100] vs 37.3%, 95% CI [20.2–54.3], p=0.01; 3y-OS: 80.8%, 95% CI [56.1–100] vs 42.3%, 95% CI [23.3–61.3], p=0.04). In conclusion, we observed point mutations of TET2 in 17% of patients, whereas TET2 deletion or UPD are very rare. In our study, TET2 mutations were clearly associated with NPM1 mutations and carried a negative prognostic impact in this subgroup. Screening for TET2 mutations may improve the characterization of CN-AML and help to identify within the low-risk subgroup with NPM1 mutation and without FLT3-ITD, patients at high risk of relapse. Disclosures: Fenaux: Celgene: Honoraria, Research Funding; Roche: Honoraria, Research Funding; Ortho Biotech: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Cephalon: Honoraria, Research Funding; Merck: Honoraria, Research Funding; Novartis: Honoraria, Research Funding.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1332-1332
Author(s):  
Frauke Theis ◽  
Andrea Corbacioglu ◽  
Verena I. Gaidzik ◽  
Peter Paschka ◽  
Daniela Späth ◽  
...  

Abstract Background Based on their association with certain biological and clinical features as well as their prognostic significance, mutations in the CCAAT/enhancer-binding protein-alpha (CEBPA) gene have been included as a provisional entity into the 2008 World Health Organization (WHO) classification of myeloid neoplasms. CEBPA mutations (CEBPAmut) are mainly found in acute myeloid leukemia (AML) with normal cytogenetics, and approximately 60% of the mutated patients (pts) carry biallelic mutations. Several studies showed that in particular pts with double mutant CEBPA (CEBPAdm) have a favorable outcome compared to all others. Recently, mutations in the transcription factor GATA2 were identified as genetic lesions potentially cooperating with CEBPAdm. Both, CEBPA and GATA2 are involved in the control of proliferation and differentiation of myeloid progenitors, and mutations in both genes are discussed as pre-disposing events in myeloid leukemia. Based on functional studies there is an important interplay between the two genes, e.g. through the formation of direct protein complexes. Finally, preliminary data suggest that the genotype CEBPAdm/GATA2 mutated (GATA2mut) is associated with a favorable outcome in AML pts. Aims To evaluate the frequency and the clinical impact of GATA2mut within a large cohort of CEBPAmut AML pts and to further analyze the CEBPAmut/GATA2mutgenotype within the context of other genetic alterations. Methods In total 202 AML pts (age 18 to 78 years) with CEBPA single mutations (n=89) or CEBPAdm (n=113) were analyzed for the presence of GATA2mut. All pts were enrolled on one of 6 AMLSG treatment trials applying intensive therapy [AMLHD93 n=15; AMLHD98A (NCT00146120) n=53; AMLHD98B n=13; AMLSG 07-04 (NCT00151242) n=74; AMLSG 06-04 (NCT00151255) n=25 and AMLSG 12-09 (NCT01180322) n=22]. GATA2 mutation screening was performed using a DNA-based PCR-assay covering exons 2 to 6 followed by Sanger sequencing. Results GATA2 mut were restricted to the cytogenetic intermediate-risk group; in total we detected 42 GATA2mut in 40 of the 202 pts (20.7%); 36 pts had CEBPAdm (36/113, 31.8%), 4 were CEBPA single mutated (4/89, 4.4%). All mutations were heterozygous, with 2 pts having two mutations (in exon 4 and 5, respectively). 31 (73.8%) of the 42 mutations were located in zinc-finger 1 (ZF1, exon 4) and 11 (26.1%) in ZF2 (exon 5). GATA2 sequence alterations included 39 missense and 3 frameshift mutations. The median follow-up of the 202 pts was 64.2 months (95%-CI: 60.1 – 75.1). First, we evaluated the clinical impact of GATA2mut in the whole cohort. Here, we found no differences in overall (OS), event-free (EFS), and relapse-free (RFS) survival as well as for the cumulative incidence of relapse (CIR) between GATA2mut and GATA2 wildtype pts. Next, the effects of GATA2mut in CEBPAdm pts (n=113) were analyzed without seeing any differences for the clinical endpoints OS, EFS, RFS and CIR. The same was also true when we investigated the impact of GATA2mut with respect to their location in the ZF domains; there were no differences between pts with ZF1 (n=29) and ZF2 (n=9) mutations, respectively. Finally, we evaluated the possible relevance of GATA2mut in the subgroup of CEBPAdm pts <60 years with intermediate-risk cytogenetics (n=94); but again GATA2mut did not impact the endpoints OS, EFS, RFS and CIR. In contrast to recently published data, we also detected GATA2mut in a small number of pts with CEBPA single mutations (n=4); however the low pt number did not allow a meaningful analysis. In addition, in our study GATA2mut occurred in rare cases with NPM1mut, FLT3-ITD or FLT3-TKD mutations. Conclusions In our study on a large cohort of CEBPA mutated AML pts we could confirm the high coincidence of GATA2 mutations, in particular in the subgroup of pts with CEBPA double mutations. However, GATA2 mutations had no impact on clinical outcome neither in the whole cohort nor in distinct pt subgroups. Disclosures: Schlegelberger: Celgene: Consultancy. Germing:Celgene: Honoraria, Research Funding. Kindler:Novartis: Membership on an entity’s Board of Directors or advisory committees. Schlenk:Novartis: Research Funding; Amgen: Research Funding; Chugai: Research Funding; Pfizer: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Ambit: Honoraria.


Genes ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1026 ◽  
Author(s):  
Cumbo ◽  
Minervini ◽  
Orsini ◽  
Anelli ◽  
Zagaria ◽  
...  

Acute myeloid leukemia (AML) clinical settings cannot do without molecular testing to confirm or rule out predictive biomarkers for prognostic stratification, in order to initiate or withhold targeted therapy. Next generation sequencing offers the advantage of the simultaneous investigation of numerous genes, but these methods remain expensive and time consuming. In this context, we present a nanopore-based assay for rapid (24 h) sequencing of six genes (NPM1, FLT3, CEBPA, TP53, IDH1 and IDH2) that are recurrently mutated in AML. The study included 22 AML patients at diagnosis; all data were compared with the results of S5 sequencing, and discordant variants were validated by Sanger sequencing. Nanopore approach showed substantial advantages in terms of speed and low cost. Furthermore, the ability to generate long reads allows a more accurate detection of longer FLT3 internal tandem duplications and phasing double CEBPA mutations. In conclusion, we propose a cheap, rapid workflow that can potentially enable all basic molecular biology laboratories to perform detailed targeted gene sequencing analysis in AML patients, in order to define their prognosis and the appropriate treatment.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xiang Zhang ◽  
Xuewu Zhang ◽  
Xia Li ◽  
Yunfei Lv ◽  
Yanan Zhu ◽  
...  

Abstract IKZF1 belongs to the IKAROS family of transcription factors, and its deletion/mutation frequently affects acute lymphoblastic leukemia. In acute myeloid leukemia, IKZF1 deletion has been demonstrated recurrent, but whether IKZF1 mutation also exists in AML remained largely unknown. Herein, we analyzed the IKZF1 mutation in AML. In our cohort, the frequency of IKZF1 mutation was 2.6% (5/193), and 5 frameshift/nonsense mutations as well as 2 missense mutations were identified in total. Molecularly, IKZF1 mutation was absent in fusion gene-positive AML, but it was demonstrated as the significant concomitant genetic alteration with SF3B1 or bi-alleleCEBPA mutation in AML. Clinically, two IKZF1, PTPN11 and SF3B1-mutated AML patients exhibited one aggressive clinical course and showed primary resistant to chemotherapy. Furthermore, we confirmed the recurrent IKZF1 mutation in AML with cBioPortal tool from OHSU, TCGA and TARGET studies. Interestingly, OHSU study also showed that SF3B1 mutation was the significant concomitant genetic alteration with IKZF1 mutation, indicating their strong synergy in leukemogenesis. In conclusion, IKZF1 mutation recurrently affected AML.


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