Renata Catalano

Early prediction of treatment outcome in acute myeloid leukemia by measurement of WT1 transcript levels in peripheral blood samples collected after chemotherapy.

The Wilms’ tumor gene WT1 is a reliable marker for minimal residual disease assessment in acute leukemia patients. The study was designed to demonstrate the potential use of WT1 to establish quality of remission in acute leukemia patients for early identification of patients at high risk of relapse. A prospective study based on a quantitative Real–Time PCR (TaqMan) assay in 562 peripheral blood samples collected from 82 acute leukemia patients at diagnosis and during follow-up was established. The evaluation of WT1 in peripheral blood samples after induction chemotherapy can distinguish the continuous complete remission patients from those who obtain only an “apparent” complete remission and who could relapse within a few months. WT1 helps identify patients at high risk of relapse soon after induction chemotherapy allowing post-induction therapy in high risk patients to be intensified.

Increase sensitivity to chemotherapeutical agents and cytoplasmatic interaction between NPM leukemic mutant and NF-κB in AML carrying NPM1 mutations

Mutations in nucleophosmin (NPM) exon 12 and the resulting delocalization of NPM into the cytoplasm are the most specific and frequent cellular events in acute myeloid leukemia patients (AML) with normal karyotype. Cytoplasmatic NPM (NPMc+) is associated with responsiveness to chemotherapy and better prognosis. The activation of nuclear factor-κB (NF-κB) has been demonstrated to occur in a subset of AML patients and is thought to induce resistance to many chemotherapeutical agents. In this study, we demonstrate the increased in vitro sensitivity of NPMc+ cells to chemotherapeutical agents and their reduced NF-κB activity. Furthermore, we provide evidence of the interaction between NPMc+ and NF-κB in the cytoplasm, resulting in the sequestration and inactivation of NF-κB. The cytosolic localization and consequent inactivation of NF-κB justifies the reduced NF-κB DNA-binding activity observed in NPMc+ patients. These data, taken together, may provide a possible explanation for the increased rate of chemosensitivity observed among the NPMc+ patients.

Valproate enhances imatinib‐induced growth arrest and apoptosis in chronic myeloid leukemia cells

The objective of this study was to evaluate the ability of the clinically available histone deacetylase (HDAC) inhibitor valproate to enhance the cytotoxicity of the Bcr‐Abl inhibitor imatinib in imatinib‐resistant cell lines.

WT1 transcript amount discriminates secondary or reactive eosinophilia from idiopathic hypereosinophilic syndrome or chronic eosinophilic leukemia

Idiopathic hypereosinophilic syndromes (HES) comprise a spectrum of indolent to aggressive diseases characterized by persistent hypereosinophilia. Hypereosinophilia can result from the presence of a defect in the hematopoietic stem cell giving rise to eosinophilia, it can be present in many myeloproliferative disorders or alternatively it may be a reactive form, secondary to many clinical conditions. The hybrid gene FIP1L1-PDGRFα was identified in a subset of patients presenting with HES or chronic eosinophilic leukemia (CEL). In spite of this, the majority of HES patients do not present detectable molecular lesions and for many of them the diagnosis is based on exclusion criteria and sometimes it remains doubt. In this study we explored the possibility to distinguish between HES/CEL and reactive hypereosinophilia based on WT1 transcript amount. For this purpose, 312 patients with hypereosinophilia were characterized at the molecular and cytogenetic level and analyzed for WT1 expression at diagnosis and during follow-up. This study clearly demonstrates that WT1 quantitative assessment allows to discriminate between HES/CEL and reactive eosinophilia and represents a useful tool for disease monitoring especially in the patients lacking a marker of clonality.

CD7/CD56-positive acute myeloid leukemias are characterized by constitutive phosphorylation of the NF-kB subunit p65 at Ser536.

CD7/CD56-positive acute myeloid leukemias are characterized by constitutive phosphorylation of the NF-kB subunit p65 at Ser536

Genetic abnormalities as targets for molecular therapies in myelodysplastic syndromes.

Abstract:  Recent advances in molecular genetics have increased knowledge regarding the mechanisms leading to myelodysplastic syndrome (MDS), secondary acute myeloid leukemia (AML), and therapy‐induced MDS. Many genetic defects underlying MDS and AML have been identified thereby allowing the development of new molecular‐targeted therapies. Several new classes of drugs have shown promise in early clinical trials and may probably alter the standard of care of these patients in the near future. Among these new drugs are farnesyltransferase inhibitors and receptor tyrosine kinase inhibitors including FLT3 and VEGF inhibitors. These agents have been tested in patients with solid tumors and hematologic malignancies such as AML and MDS. Most of the studies in MDS are still in early stages of development. The DNA hypomethylating compounds azacytidine and decitabine may reduce hypermethylation and induce re‐expression of key tumor suppressor genes in MDS. Biochemical compounds with histone deacetylase inhibitory activity, such as valproic acid (VPA), have been tested as antineoplastic agents. Finally, new vaccination strategies are developing in MDS patients based on the identification of MDS‐associated antigens. Future therapies will attempt to resolve cytopenias in MDS, eliminate malignant clones, and allow differentiation by attacking specific mechanisms of the disease.

Retraction Note to: Increase sensitivity to chemotherapeutical agents and cytoplasmatic interaction between the NPM leukemic mutant and NF-κB in AML carrying NPM1 mutations

The authors of the above article would like to retract it due to an inaccuracy in Figure 5. The remainder of the data presented is sound and fully supports the scientific conclusions of the paper. Dr Francesca Messa, a biologist of the Department of Clinical and Biological Sciences, University of Turin, Turin, Italy, has admitted to intentionally providing false confocal images (Figure 5a and b). Professor G Saglio states categorically that the other authors of this paper were not involved in or aware of these events.