Acute myeloid leukemia (AML) carrying NPM1 mutations and cytoplasmic nucleophosmin (NPMc؉ AML) accounts for about one-third of adult AML and shows distinct features, including a unique gene expression profile. MicroRNAs (miRNAs) are small noncoding RNAs of 19 -25 nucleotides in length that have been linked to the development of cancer. Here, we investigated the role of miRNAs in the biology of NPMc؉ AML. The miRNA expression was evaluated in 85 adult de novo AML patients characterized for subcellular localization/ mutation status of NPM1 and FLT3 mutations using a custom microarray platform. Data were analyzed by using univariate t test within BRB tools. We identified a strong miRNA signature that distinguishes NPMc؉ mutated (n ‫؍‬ 55) from the cytoplasmic-negative (NPM1 unmutated) cases (n ‫؍‬ 30) and includes the up-regulation of miR-10a, miR-10b, several let-7 and miR-29 family members. Many of the down-regulated miRNAs including miR-204 and miR-128a are predicted to target several HOX genes. Indeed, we confirmed that miR-204 targets HOXA10 and MEIS1, suggesting that the HOX upregulation observed in NPMc؉ AML may be due in part by loss of HOX regulators-miRNAs. FLT3-ITD؉ samples were characterized by upregulation of miR-155. Further experiments demonstrated that the up-regulation of miR-155 was independent from FLT3 signaling. Our results identify a unique miRNA signature associated with NPMc؉ AML and provide evidence that support a role for miRNAs in the regulation of HOX genes in this leukemia subtype. Moreover, we found that miR-155 was strongly but independently associated with FLT3-ITD mutations. FLT3-ITD ͉ HOX ͉ NPM1A cute myeloid leukemia (AML) arises from multiple and sequential genetic alterations involving hematopoietic precursors (1). In Ϸ25% of cases, specific chromosomal translocations like the t(8;21), inv(16) or t(15;17) represent the initial events leading to malignant transformation (1) and are associated with a good outcome. In contrast, 40-50% of AMLs have normal karyotype by conventional banding analysis and are characterized by great molecular and clinical heterogeneity (2). Recent work has identified novel molecular abnormalities in normal karyotype AML (NK-AML) that has improved the classification and risk stratification of this large subgroup of patients. Among them, internal tandem duplications in the juxta-membrane domain or mutations in the second tyrosine kinase domain (TKD) of the FLT3 gene have been found in 30-45% of NK-AML (3). Both types of mutations constitutively activate FLT3 and FLT3-ITD mutations have been associated with increased risk of relapse (4). Mutations in the myeloid transcription factor CEBPA have been detected in 10-15% of NK-AML (5) and are associated with favorable prognosis (5, 6).Mutations of the nucleophosmin (NPM1) gene, usually occurring at exon-12 (7) and more rarely at exon-11 (8) represent the most common genetic alteration in AML-NK (50-60% of cases) and account for about one-third of all adult AML (7). This gene encodes for a ubiquitously expressed...

In a randomized trial of therapy for FMS-like tyrosine kinase-3 (FLT3) mutant acute myeloid leukemia in first relapse, 224 patients received chemotherapy alone or followed by 80 mg of the FLT3 inhibitor lestaurtinib twice daily. Endpoints included complete remission or complete remission with incomplete platelet recovery (CR/CRp), overall survival, safety, and tolerability. Correlative studies included pharmacokinetics and analysis of in vivo FLT3 inhibition. There were 29 patients with CR/CRp in the lestaurtinib arm and 23 in the control arm (26% vs 21%; P = .35), and no difference in overall survival between the 2 arms. There was evidence of toxicity in the lestaurtinib-treated patients, particularly those with plasma levels in excess of 20 μM. In the lestaurtinib arm, FLT3 inhibition was highly correlated with remission rate, but target inhibition on day 15 was achieved in only 58% of patients receiving lestaurtinib. Given that such a small proportion of patients on this trial achieved sustained FLT3 inhibition in vivo, any conclusions regarding the efficacy of combining FLT3 inhibition with chemotherapy are limited. Overall, lestaurtinib treatment after chemotherapy did not increase response rates or prolong survival of patients with FLT3 mutant acute myeloid leukemia in first relapse. This study is registered at www.clinicaltrials.gov as #NCT00079482.

IntroductionPhiladelphia chromosome-positive (Ph ϩ ) acute lymphoblastic leukemia (ALL) occurs in 25% to 30% of adults and in approximately 4% of children with ALL, [1][2][3][4][5][6] and is associated with a very poor prognosis. The reported incidence in the elderly (Ͼ 60 years) seems even higher, 7 with more unfavorable results and a median survival of less than one year. 8,9 In the last few years, studies aimed at testing the activity of different associations of imatinib and chemotherapy as frontline treatment for Ph ϩ patients with ALL have been carried out, both for younger adults 10-13 and for elderly patients. [14][15][16] The question of whether a chemotherapy-free treatment, based only on imatinib plus steroids, could effectively control the disease by inducing durable hematologic and/or molecular responses, is still open. This report summarizes our results on a total of 30 elderly Ph ϩ patients with ALL who received imatinib plus steroids in induction and imatinib in consolidation until relapse or death. Patients, materials, and methods PatientsPatients were treated according to the Gruppo Italiano Malattie Ematologiche dell'Adulto (GIMEMA) LAL0201-B protocol, which had been approved by the internal review board and by the ethics committee of the trial coordinating center, as well as by the local ethics committee of each participating institution. Patients with a diagnosis of ALL who were older than 60 years of age were eligible for this study if they carried either the Ph chromosome or the BCR-ABL molecular translocation. Written informed consent was obtained from each patient in accordance with the Declaration of Helsinki. BCR-ABL diagnosis and monitoringAll molecular examinations at diagnosis and during the follow-up were performed in the same reference GIMEMA laboratory. 17 Total RNA was extracted from bone marrow (BM) cells. cDNA synthesis and reverse transcriptasepolymerase chain reaction (RT-PCR) specific for the BCR-ABL transcripts encoding either the p190 Bcr-Abl or the p210 Bcr-Abl proteins were performed using the standardized BIOMED-1 protocol. 18 Quantitative real-time PCR (Q-RT-PCR) analysis of minimal residual disease was carried out using the methods standardized within a Europe Union concerted action program. 19 ABL was used as the control gene and the BCR-ABL values were expressed as a percentage of the ABL transcript levels of ABL. Study design and therapyPatients were assigned to receive a 7-day steroid pretreatment (prednisone, at increasing doses from 10 to 40 mg/m 2 per day) followed by induction treatment with imatinib at the fixed dose of 800 mg/d, associated to steroids (prednisone by mouth at the dose of 40 mg/m 2 per day) from day 1 to day 45. Response evaluation was carried out at day 45. Assessments of BM aspirates, including molecular biology evaluation, were planned after the response evaluation, at the second, fourth, and sixth month from complete remission (CR), and/or at the time of possible relapse. For personal use only. on May 12, 2018. by guest www.bloodjournal....

Dasatinib is a potent BCR-ABL inhibitor effective in chronic myeloid leukemia and Ph ؉ acute lymphoblastic leukemia (ALL) resistant/intolerant to imatinib. In the GIMEMA LAL1205 protocol, patients with newly diagnosed Ph ؉ ALL older than 18 years (with no upper age limit) received dasatinib induction therapy for 84 days combined with steroids for the first 32 days and intrathecal chemotherapy. Postremission therapy was free. Fiftythree patients were evaluable (median age, 53.6 years). All patients achieved a complete hematologic remission (CHR), 49 (92.5%) at day 22. At this time point, 10 patients achieved a BCR-ABL reduction to < 10 ؊3 . At 20 months, the overall survival was 69.2% and disease-free survival was 51.1%. A significant difference in DFS was observed between patients who showed at day 22 a decrease in BCR-ABL levels to < 10 ؊3 compared with patients who never reached these levels during induction. In multivariate analysis, BCR-ABL levels of < 10 ؊3 at day 85 correlated with disease-free survival. No deaths or relapses occurred during induction. Twenty-three patients relapsed after completing induction. A T315I mutation was detected in 12 of 17 relapsed cases. Treatment was well tolerated; only 4 patients discontinued therapy during the last phase of the induction when already in CHR. In adult Ph ؉ ALL, induction treatment with dasatinib plus steroids is associated with a CHR in virtually all patients, irrespective of age, good compliance, no deaths, and a very rapid debulking of the neoplastic clone. IntroductionDespite an improved understanding of the biology of acute lymphoblastic leukemia (ALL), the overall prognosis of adult patients remains unsatisfactory. 1-3 The Philadelphia (Ph) chromosome is the most frequent genetic abnormality in adult ALL; its prevalence increases with age, accounting for 12% to 30% in patients 18 to 35 years of age, 40% to 45% in patients 36 to 50 years of age, 4,5 and Ͼ 50% in patients older than 60 years. 6 The Ph chromosome and BCR-ABL fusion gene have been associated with a highly unfavorable prognosis, independent of age, 7,8 and elderly patients were often treated only with supportive therapy.The tyrosine kinase inhibitor (TKI) imatinib has profoundly altered the management of patients with chronic myeloid leukemia and impacted on the natural course of the disease. 9,10 Imatinib has also been effectively used in Ph ϩ ALL, both in adults and children. [11][12][13] In a GIMEMA study, all 29 Ph ϩ ALL patients aged 60 years of age or older treated with imatinib plus prednisone without chemotherapy as first-line treatment obtained a complete hematologic remission (CHR). 14 The GMALL study group also showed that, in elderly patients with de novo Ph ϩ ALL, induction with imatinib resulted in a significantly higher CR rate and lower toxicity than with chemotherapy. 15 Dasatinib is a second-generation TKI with a 300-fold greater activity than imatinib in vitro. 16,17 Dasatinib has demonstrated a marked efficacy in patients with CML after relapse or resistance to imatinib...

We conclude that IKZF1 deletions are likely to be a genomic alteration that significantly affects the prognosis of Ph-positive ALL in adults.