Barbara Scappini

Searching for the Magic Bullet Against Cancer: The Butyrate Saga

n -Butyric acid and its “polymorphic” derivatives have been largely but somehow “blindly” studied in oncology and in red cell diseases with consistent results through decades indicating a strong maturative effect determined by enhancement of gene transcription. Although these effects have been observed mainly in vitro, the relative absence of systemic toxicity of butyrates render these compounds appealing as specific therapeutic agents. More interestingly, their specific mechanism of action, i.e. inhibition of histone deacetylase and de-repression of transcription represents at present an unique tool for diseases such as acute leukemias which are characterised by a disregulation of co-repressors and co-activators of gene transcription. More insight into specificity and modalities of action of different butyrate derivatives may be a guarantee for excellent tailored antileukemic therapy in the future.

Concomitant occurrence of BCR-ABL and JAK2V617F mutation

To the editor: In a recent issue of the journal, Makishima et al[1][1] reported on the occurrence of mutations typically associated with Philadelphia-chromosome (Ph1) negative myeloproliferative (MPN)/ myelodysplastic neoplasms in 54 patients with typical chronic myelogenous leukemia (CML) in

Cytarabine and clofarabine after high-dose cytarabine in relapsed or refractory AML patients

Clofarabine has been shown to be effective in AML patients, either as single agent or, mainly, in association with intermediate dose cytarabine. Based on these reports, we conducted a preliminary study combining clofarabine and intermediate dose cytarabine in AML patients who relapsed or failed to respond to at least two induction therapies. We treated 47 patients affected by relapsed/refractory AML with a regimen including clofarabine at 22.5 mg/m2 daily on days 1–5, followed after 3 hr by cytarabine at 1 g/m2 daily on days 1–5. Ten patients received a further consolidation cycle with clofarabine at 22.5 mg/m2 and cytarabine at 1 g/m2 day 1–4. Among the 47 patients, 24/47 (51%) achieved a complete remission, 5/47 (10.5%) a partial response, 10/47 (21%) had a resistant disease, and 6/47 (13%) died of complications during the aplastic phase. The most frequent nonhematologic adverse events were vomiting, diarrhea, transient liver toxicity, febrile neutropenia, and infections microbiologically documented. Among the 24 patients who obtained a CR 13 underwent allogeneic bone marrow transplantation. In 14 patients, complete remission duration was shorter than 12 months, whereas 10 patients experienced longer complete remission duration. These very preliminary results suggest that clofarabine‐cytarabine regimen is effective in this particularly poor prognosis category of patients, representing a potential “bridge” toward bone marrow transplant procedures. Safety data were consistent with previously reported salvage therapies. Further studies and a longer follow up are warranted. Am. J. Hematol., 2012.

Regioselective synthesis and biological profiling of butyric and phenylalkylcarboxylic esters derivated from D-mannose and xylitol : influence of alkyl chain length on acute toxicity

Regiospecific synthesis of 12 novel n-butyric and phenylalkylcarboxylic monoesters of mannose and xylitol was achieved. The strategy adopted, avoided a tedious intramolecular transesterification step, previously described for the synthesis of analogous compounds and permitted the facile synthesis of a new generation of stable derivatives. The general tolerance of the drugs has been assayed after intravenous administration of a bolus dose into mice. Monobutyric esters showed a low toxicity commensurate with the requirements for future development. A relationship was observed between chain length and toxicity. In contrast, phenylacetic, 3-phenylpropionic and 4-phenylbutyric esters were found to be toxic. Phenylbutyric esters induced marked and specific neuromuscular damage. Preliminary biological investigations of the new series of monobutyric esters showed them to retain the benificial biological properties of butyric acid whilst remaining relatively non toxic. They induced an inhibition of in vitro proliferation of 10 human cases of de novo acute myeloid leukemia (AML) primary cultures and AML established cell lines. AML blasts growth appeared to be blocked and cell differentiation was established. Transcription and expression of maturation markers and finally apoptosis were observed. Moreover, human gamma-chain hemoglobin (HbF) synthesis in erythroleukemia cells was stimulated by monobutyric esters. Mannose and xylitol butyric derivatives would appear to have exciting potential in treatment of beta-Hemoglobinopathies, sickle cell anemia and cancer.

Genetic predisposition and induced pro-inflammatory/pro-oxidative status may play a role in increased atherothrombotic events in nilotinib treated chronic myeloid leukemia patients

Several reports described an increased risk of cardiovascular (CV) events, mainly atherothrombotic, in Chronic Myeloid Leukemia (CML) patients receiving nilotinib. However, the underlying mechanism remains elusive. The objective of the current cross-sectional retrospective study is to address a potential correlation between Tyrosine Kinase Inhibitors (TKIs) treatment and CV events. One hundred and 10 chronic phase CML patients in complete cytogenetic response during nilotinib or imatinib, were screened for CV events and evaluated for: traditional CV risk factors, pro/anti-inflammatory biochemical parameters and detrimental ORL1 gene polymorphisms (encoding for altered oxidized LDL receptor-1). Multivariate analysis of the whole cohort showed that the cluster of co-existing nilotinib treatment, dyslipidaemia and G allele of LOX-1 polymorphism was the only significant finding associated with CV events. Furthermore, multivariate analysis according to TKI treatment confirmed IVS4-14 G/G LOX-1 polymorphism as the strongest predictive factor for a higher incidence of CV events in nilotinib patients. Biochemical assessment showed an unbalanced pro-inflammatory cytokines network in nilotinib vs imatinib patients. Surprisingly, pre-existing traditional CV risk factors were not always predictive of CV events. We believe that in nilotinib patients an induced “inflammatory/oxidative status”, together with a genetic pro-atherothrombotic predisposition, may favour the increased incidence of CV events. Prospective studies focused on this issue are ongoing.

CXCR4 expression accounts for clinical phenotype and outcome in acute myeloid leukemia

In acute myeloid leukemia (AML), CXCR4 expression has been correlated with leukocytosis and prognosis.

Glycosylphosphatidylinositol-specific T cells,IFNγ-producing T cells,and pathogenesis of idiopathic aplastic anemia

To the editor: In idiopathic aplastic anemia (IAA), bone marrow failure (BMF) is caused by depletion of hematopoietic stem cells (HSCs), thought to result from a T-cell-mediated autoimmune process.[1][1] Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal hematopoietic disorder characterized by a

The hOCT1 and ABCB1 polymorphisms do not influence the pharmacodynamics of nilotinib in chronic myeloid leukemia

First-line nilotinib in chronic myeloid leukemia is more effective than imatinib to achieve early and deep molecular responses, despite poor tolerability or failure observed in one-third of patients. The toxicity and efficacy of tyrosine kinase inhibitors might depend on the activity of transmembrane transporters. However, the impact of transporters genes polymorphisms in nilotinib setting is still debated. We investigated the possible correlation between single nucleotide polymorphisms of hOCT1 (rs683369 [c.480C>G]) and ABCB1 (rs1128503 [c.1236C>T], rs2032582 [c.2677G>T/A], rs1045642 [c.3435C>T]) and nilotinib efficacy and toxicity in a cohort of 78 patients affected by chronic myeloid leukemia in the context of current clinical practice. The early molecular response was achieved by 81% of patients while 64% of them attained deep molecular response (median time, 26 months). The 36-month event-free survival was 86%, whereas 58% of patients experienced toxicities. Interestingly, hOCT1 and ABCB1 polymorphisms alone or in combination did not influence event-free survival or the adverse events rate. Therefore, in contrast to data obtained in patients treated with imatinib, hOCT1 and ABCB1 polymorphisms do not impact on nilotinib efficacy or toxicity. This could be relevant in the choice of the first-line therapy: patients with polymorphisms that negatively condition imatinib efficacy might thus receive nilotinib as first-line therapy.

Multilineage dysplasia as assessed by immunophenotype has no impact on clinical-biological features and outcome of NPM1-mutated acute myeloid leukemia

The presence of multilineage dysplasia (MLD) by morphology at diagnosis in acute myeloid leukemia (AML) defines a separate subset in the World Health Organization classification with still-debated prognostic value. A major controversy concerns MLDs role in NPM1-mutated (NPM1⁺) AML, which correlates with good prognosis. We used flow cytometry (FC), an emerging technique for assessing dysplasia, to investigate MLD in NPM1⁺ AML by an immunophenotypic score (IPS), a technique previously adopted in myelodysplastic syndrome. Eighty-five intensively treated NPM1⁺ AML cases were studied. Patients were grouped according to the combination of data in maturing cell compartments. FC-assessed dysplasia showed a significant correlation with morphology-assessed dysplasia, showing the efficacy of this method in highlighting dysplasia in AML. Except for MLD, IPS did not influence any patient- or disease-related characteristics at diagnosis. Furthermore, IPS did not influence complete remission rate, disease-free survival, or overall survival. By investigating NPM1 status on separated cell compartments, we established a correlation between FC-assessed MLD and belonging to AML clone. This study shows that dysplasia evaluated by immunophenotype has no impact on clinical-biological characteristics or on outcome of NPM1⁺ AML. Dysplasia is part of the spectrum of NPM1⁺ AML, and the prognostic stratification of this category of patients should not be based upon it.

CEBPA-double-mutated acute myeloid leukemia displays a unique phenotypic profile : a reliable screening method and insight into biological features

Mutations in CCAAT/enhancer binding protein α (CEBPA) occur in 5–10% of cases of acute myeloid leukemia. CEBPA-double-mutated cases usually bear biallelic N- and C-terminal mutations and are associated with a favorable clinical outcome. Identification of CEBPA mutants is challenging because of the variety of mutations, intrinsic characteristics of the gene and technical issues. Several screening methods (fragment-length analysis, gene expression array) have been proposed especially for large-scale clinical use; although efficient, they are limited by specific concerns. We investigated the phenotypic profile of blast and maturing bone marrow cell compartments at diagnosis in 251 cases of acute myeloid leukemia. In this cohort, 16 (6.4%) patients had two CEBPA mutations, whereas ten (4.0%) had a single mutation. First, we highlighted that the CEBPA-double-mutated subset displays recurrent phenotypic abnormalities in all cell compartments. By mutational analysis after cell sorting, we demonstrated that this common phenotypic signature depends on CEBPA-double-mutated multi-lineage involvement. From a multidimensional study of phenotypic data, we developed a classifier including ten core and widely available parameters. The selected markers on blasts (CD34, CD117, CD7, CD15, CD65), neutrophil (SSC, CD64), monocytic (CD14, CD64) and erythroid (CD117) compartments were able to cluster CEBPA-double-mutated cases. In a validation set of 259 AML cases from three independent centers, our classifier showed excellent performance with 100% specificity and 100% sensitivity. We have, therefore, established a reliable screening method, based upon multidimensional analysis of widely available phenotypic parameters. This method provides early results and is suitable for large-scale detection of CEBPA-double-mutated status, allowing gene sequencing to be focused in selected cases.