Detection of mutant NPM1 mRNA in acute myeloid leukemia (AML) using custom gene expression arrays [Training cohort]
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ABSTRACT: Abstract Mutations in the gene encoding nucleophosmin (NPM1) carry prognostic value for patients with acute myeloid leukemia (AML). Various techniques are currently being used to detect these mutations in routine molecular diagnostics. Incorporation of accurate NPM1 mutation detection on a gene expression platform would enable simultaneous detection with various other expression biomarkers. Here we present an array based mutation detection using custom probes for NPM1 WT mRNA and NPM1 type A, B, and D mutant mRNA. This method was 100% accurate on a training cohort of 505 newly diagnosed unselected AML cases. Validation on an independent cohort of 143 normal karyotype AML cases revealed no false negative results, and one false positive (sensitivity 100.0%, and specificity 98.7%). Based on this, we conclude that this method provides a reliable method for NPM1 mutation detection. The method can be applied to other genes/mutations as long as the mutant alleles are sufficiently high expressed. Training cohort of 505 AML cases analyzed using the AMLprofiler
Project description:Abstract Mutations in the gene encoding nucleophosmin (NPM1) carry prognostic value for patients with acute myeloid leukemia (AML). Various techniques are currently being used to detect these mutations in routine molecular diagnostics. Incorporation of accurate NPM1 mutation detection on a gene expression platform would enable simultaneous detection with various other expression biomarkers. Here we present an array based mutation detection using custom probes for NPM1 WT mRNA and NPM1 type A, B, and D mutant mRNA. This method was 100% accurate on a training cohort of 505 newly diagnosed unselected AML cases. Validation on an independent cohort of 143 normal karyotype AML cases revealed no false negative results, and one false positive (sensitivity 100.0%, and specificity 98.7%). Based on this, we conclude that this method provides a reliable method for NPM1 mutation detection. The method can be applied to other genes/mutations as long as the mutant alleles are sufficiently high expressed. Validation cohort of 143 AML cases analyzed using the AMLprofiler
Project description:Abstract Mutations in the gene encoding nucleophosmin (NPM1) carry prognostic value for patients with acute myeloid leukemia (AML). Various techniques are currently being used to detect these mutations in routine molecular diagnostics. Incorporation of accurate NPM1 mutation detection on a gene expression platform would enable simultaneous detection with various other expression biomarkers. Here we present an array based mutation detection using custom probes for NPM1 WT mRNA and NPM1 type A, B, and D mutant mRNA. This method was 100% accurate on a training cohort of 505 newly diagnosed unselected AML cases. Validation on an independent cohort of 143 normal karyotype AML cases revealed no false negative results, and one false positive (sensitivity 100.0%, and specificity 98.7%). Based on this, we conclude that this method provides a reliable method for NPM1 mutation detection. The method can be applied to other genes/mutations as long as the mutant alleles are sufficiently high expressed.
Project description:Abstract Mutations in the gene encoding nucleophosmin (NPM1) carry prognostic value for patients with acute myeloid leukemia (AML). Various techniques are currently being used to detect these mutations in routine molecular diagnostics. Incorporation of accurate NPM1 mutation detection on a gene expression platform would enable simultaneous detection with various other expression biomarkers. Here we present an array based mutation detection using custom probes for NPM1 WT mRNA and NPM1 type A, B, and D mutant mRNA. This method was 100% accurate on a training cohort of 505 newly diagnosed unselected AML cases. Validation on an independent cohort of 143 normal karyotype AML cases revealed no false negative results, and one false positive (sensitivity 100.0%, and specificity 98.7%). Based on this, we conclude that this method provides a reliable method for NPM1 mutation detection. The method can be applied to other genes/mutations as long as the mutant alleles are sufficiently high expressed.
Project description:Among acute myeloid leukemias (AML) with normal karyotype (CN-AML), NPM1 and CEBPA mutations define WHO provisional entities accounting for ~60% of cases, but the remaining ~40% remains poorly characterized. By whole exome-sequencing (WES) of one CN-AML patient lacking mutations in NPM1, CEBPA, FLT3, MLL-PTD and IDH1, we newly identified a clonal somatic mutation in BCOR (BCL6 co-repressor), a gene located in chromosome X. Further analyses showed that BCOR mutations occurred in 11/262 (4.2%) CN-AML cases and represented a substantial fraction (14/82, 17.1%) of CN-AML patients showing the same genetic background as the index patient subjected to WES. BCOR somatic mutations were: i) disruptive events similar to germline BCOR mutations causing the oculo-cranio-facial-dental (OCFD) genetic syndrome; ii) associated with markedly decreased BCOR mRNA levels, absence of full-length BCOR and absent or low expression of a truncated BCOR protein; iii) almost mutually exclusive with NPM1 mutations and frequently associated with DNMT3A and RUNX1 mutations, pointing to a cooperation between these events. Finally, BCOR mutations correlated with poor outcome among a cohort of 160 CN-AML patients (28% versus 66% overall survival at 2 yrs, P=0.024). Our results implicate for the first time BCOR in the pathogenesis of CN-AML without NPM1 mutations. AML samples with normal karyotype were studied. Molecular analyses were performed for BCOR mutations. 12 BCOR wild-type cases and 12 BCOR mutated cases were hybridized to gene expression micro-arrays.
Project description:Among acute myeloid leukemias (AML) with normal karyotype (CN-AML), NPM1 and CEBPA mutations define WHO provisional entities accounting for ~60% of cases, but the remaining ~40% remains poorly characterized. By whole exome-sequencing (WES) of one CN-AML patient lacking mutations in NPM1, CEBPA, FLT3, MLL-PTD and IDH1, we newly identified a clonal somatic mutation in BCOR (BCL6 co-repressor), a gene located in chromosome X. Further analyses showed that BCOR mutations occurred in 11/262 (4.2%) CN-AML cases and represented a substantial fraction (14/82, 17.1%) of CN-AML patients showing the same genetic background as the index patient subjected to WES. BCOR somatic mutations were: i) disruptive events similar to germline BCOR mutations causing the oculo-cranio-facial-dental (OCFD) genetic syndrome; ii) associated with markedly decreased BCOR mRNA levels, absence of full-length BCOR and absent or low expression of a truncated BCOR protein; iii) almost mutually exclusive with NPM1 mutations and frequently associated with DNMT3A and RUNX1 mutations, pointing to a cooperation between these events. Finally, BCOR mutations correlated with poor outcome among a cohort of 160 CN-AML patients (28% versus 66% overall survival at 2 yrs, P=0.024). Our results implicate for the first time BCOR in the pathogenesis of CN-AML without NPM1 mutations.
Project description:Mutation in the nucleophosmin (NPM1) gene is frequent in acute myeloid leukemia (AML). This mutation has remarkable prognostic significance and correlates with distinct biological features. Our data from the sample-paired microRNA (miRNA) and mRNA microarrays of de novo AML patients strongly indicated that miRNAâmRNA regulation (MMR) may be dynamic and can be modulated by NPM1 mutation. We identified 493 NPM1 mutation-modulated MMR pairs by a systematic framework, in which MMR was attenuated specifically in patients carrying NPM1 mutations. The involved miRNAs/mRNAs were associated with cancer and hematological diseases, as well as known functions of NPM1 mutation including cell death and cellular response to therapeutics. The NPM1 mutation modulation could be validated with three approaches, including two independent cohort datasets, a high-throughput dataset derived from cell line-based experiments, and two in vitro models. Our study provides novel biological insights into the role of NPM1 mutation as a modulator of MMR, based on which novel prognostic markers are derived in AML. Cryopreserved bone marrow cells were obtained from 109 de novo AML patients. Each sample was analyzed with Illumina HumanHT-12 V4.0 expression beadchip.
Project description:Mutation in the nucleophosmin (NPM1) gene is frequent in acute myeloid leukemia (AML). This mutation has remarkable prognostic significance and correlates with distinct biological features. Our data from the sample-paired microRNA (miRNA) and mRNA microarrays of de novo AML patients strongly indicated that miRNAâmRNA regulation (MMR) may be dynamic and can be modulated by NPM1 mutation. We identified 493 NPM1 mutation-modulated MMR pairs by a systematic framework, in which MMR was attenuated specifically in patients carrying NPM1 mutations. The involved miRNAs/mRNAs were associated with cancer and hematological diseases, as well as known functions of NPM1 mutation including cell death and cellular response to therapeutics. The NPM1 mutation modulation could be validated with three approaches, including two independent cohort datasets, a high-throughput dataset derived from cell line-based experiments, and two in vitro models. Our study provides novel biological insights into the role of NPM1 mutation as a modulator of MMR, based on which novel prognostic markers are derived in AML. Cryopreserved bone marrow cells were obtained from 109 de novo AML patients. Each sample was analyzed with nCounter® Human miRNA Expression Array.
Project description:Mutations in CCAAT/enhancer binding protein alpha (CEBPA) are seen in 5-14% of acute myeloid leukemia (AML) and have been associated with a favorable clinical outcome. Most AMLs with CEBPA mutations simultaneously carry two mutations (CEBPAdouble-mut), usually biallelic, while single heterozygous mutations (CEBPAsingle-mut) are less frequently seen. Using denaturing high performance liquid chromatography and nucleotide sequencing we identified among a cohort of 598 newly diagnosed AMLs a subset of 41 CEBPA mutant cases, i.e. 28 CEBPAdouble-mut and 13 CEBPAsingle-mut cases. CEBPAdouble-mut associated with a unique gene expression profile as well as favorable overall and event-free survival, retained in multivariable analysis that included cytogenetic risk, FLT3-ITD and NPM1 mutation, white blood cell count and age. In contrast, CEBPAsingle-mut AMLs did not express a discriminating signature and could not be distinguished from wild type cases as regards clinical outcome. These results demonstrate significant underlying heterogeneity within CEBPA mutation positive AML with prognostic relevance. Experiment Overall Design: Gene expression profiling of 524 cases of de novo AML. Comparisons of cases with double and single CEBPA mutations versus those with wild type CEBPA.
Project description:Mutation in the nucleophosmin (NPM1) gene is frequent in acute myeloid leukemia (AML). This mutation has remarkable prognostic significance and correlates with distinct biological features. Our data from the sample-paired microRNA (miRNA) and mRNA microarrays of de novo AML patients strongly indicated that miRNA−mRNA regulation (MMR) may be dynamic and can be modulated by NPM1 mutation. We identified 493 NPM1 mutation-modulated MMR pairs by a systematic framework, in which MMR was attenuated specifically in patients carrying NPM1 mutations. The involved miRNAs/mRNAs were associated with cancer and hematological diseases, as well as known functions of NPM1 mutation including cell death and cellular response to therapeutics. The NPM1 mutation modulation could be validated with three approaches, including two independent cohort datasets, a high-throughput dataset derived from cell line-based experiments, and two in vitro models. Our study provides novel biological insights into the role of NPM1 mutation as a modulator of MMR, based on which novel prognostic markers are derived in AML.
Project description:Mutation in the nucleophosmin (NPM1) gene is frequent in acute myeloid leukemia (AML). This mutation has remarkable prognostic significance and correlates with distinct biological features. Our data from the sample-paired microRNA (miRNA) and mRNA microarrays of de novo AML patients strongly indicated that miRNA−mRNA regulation (MMR) may be dynamic and can be modulated by NPM1 mutation. We identified 493 NPM1 mutation-modulated MMR pairs by a systematic framework, in which MMR was attenuated specifically in patients carrying NPM1 mutations. The involved miRNAs/mRNAs were associated with cancer and hematological diseases, as well as known functions of NPM1 mutation including cell death and cellular response to therapeutics. The NPM1 mutation modulation could be validated with three approaches, including two independent cohort datasets, a high-throughput dataset derived from cell line-based experiments, and two in vitro models. Our study provides novel biological insights into the role of NPM1 mutation as a modulator of MMR, based on which novel prognostic markers are derived in AML.