Pogosova-Agadjanyan, Era L

AbstractIntroductionAcute myeloid leukemia (AML) remains one of the deadliest hematopoietic malignancies. A better understanding of the molecular biology governing AML may lead to improved risk stratification and facilitate the development of novel therapies. Proteins are responsible for much of the biology of cells. Several studies have examined the global proteome in bulk mononuclear cells (MNCs) from AML specimens, which are comprised a heterogenous population of cells at various stages of differentiation.MethodsGiven the potential impact of the nonleukemic cells on protein expression profiles, we applied an integrative proteogenomic approach utilizing next‐generation sequencing and mass spectrometry‐based proteomics to identify novel protein biomarkers in unsorted MNCs and viable leukemic blasts (VLBs) isolated from blood and bone marrow specimens obtained at the time of AML diagnosis.ResultsWe identified significant differences in protein expression between VLBs and MNCs. Subsequent studies (N = 27) focused on proteomic profiling of VLBs that identified novel candidate biomarkers associated with mutational genotypes and clinical outcome, some of which were recapitulated in an independent cohort of patients. Using mass spectrometry, we also detected mutated protein products, some of which were predicted via in silico analyses to be potential neoantigens amenable to adoptive immunotherapy. As previously described, analyses comparing transcript and protein expression showed an overall modest correlation between mRNA and protein dataset, but enriching for genes associated with mutations significantly improved the protein–RNA correlation.ConclusionTogether, the results provide insight into the biology of VLBs and demonstrate the gains derived from examining the proteome in addition to genome and transcriptome.

AbstractSomatic mutations in isocitrate dehydrogenase (IDH) genes occur frequently in adult acute myeloid leukemia (AML) and less commonly in pediatric AML. The objective of this study was to describe the prevalence, mutational profile, and prognostic significance of IDH mutations in AML across age. Our cohort included 3141 patients aged between <1 month and 88 years treated on Children’s Cancer Group/Children’s Oncology Group (n = 1872), Southwest Oncology Group (n = 359), Eastern Cooperative Oncology Group (n = 397) trials, and in Beat AML (n = 333) and The Cancer Genome Atlas (n = 180) genomic characterization cohorts. We retrospectively analyzed patients in 4 age groups (age range, n): pediatric (0-17, 1744), adolescent/young adult (18-39, 444), intermediate-age (40-59, 640), older (≥60, 309). IDH mutations (IDHmut) were identified in 9.2% of the total cohort (n = 288; IDH1 [n = 123, 42.7%]; IDH2 [n = 165, 57.3%]) and were strongly correlated with increased age: 3.4% pediatric vs 21% older, P < .001. Outcomes were similar in IDHmut and IDH-wildtype (IDHWT) AML (event-free survival [EFS]: 35.6% vs 40.0%, P = .368; overall survival [OS]: 50.3% vs 55.4%, P = .196). IDH mutations frequently occurred with NPM1 (47.2%), DNMT3A (29.3%), and FLT3-internal tandem duplication (ITD) (22.4%) mutations. Patients with IDHmut AML with NPM1 mutation (IDHmut/NPM1mut) had significantly improved survival compared with the poor outcomes experienced by patients without (IDHmut/NPM1WT) (EFS: 55.1% vs 17.0%, P < .001; OS: 66.5% vs 35.2%, P < .001). DNTM3A or FLT3-ITD mutations in otherwise favorable IDHmut/NPM1mut AML led to inferior outcomes. Age group analysis demonstrated that IDH mutations did not abrogate the favorable prognostic impact of NPM1mut in patients aged <60 years; older patients had poor outcomes regardless of NPM1 status. These trials were registered at www.clinicaltrials.gov as #NCT00070174, #NCT00372593, #NCT01371981, #NCT00049517, and #NCT00085709.