Neoplasia publishes the results of novel investigations in all areas of oncology research.

In this study we investigated whether neoplastic transformation occurring in Philadelphia (Ph)–negative myeloproliferative neoplasms (MPNs) could involve also the endothelial cell compartment. We evaluated the level of endothelial colony-forming cells (E-CFCs) in 42 patients (15 with polycythemia vera, 12 with essential thrombocythemia, and 15 with primary myelofibrosis). All patients had 1 molecular abnormality (JAK2^V617F or MPL^W515K mutations, SOCS gene hypermethylation, clonal pattern of growth) detectable in their granulocytes. The growth of colonies was obtained in 22 patients and, among them, patients with primary myelofibrosis exhibited the highest level of E-CFCs. We found that E-CFCs exhibited no molecular abnormalities in12 patients, had SOCS gene hypermethylation, were polyclonal at human androgen receptor analysis in 5 patients, and resulted in JAK2^V617F mutated and clonal in 5 additional patients, all experiencing thrombotic complications. On the whole, patients with altered E-CFCs required antiproliferative therapy more frequently than patients with normal E-CFCs. Moreover JAK2^V617F-positive E-CFCs showed signal transducer and activator of transcription 5 and 3 phosphorylation rates higher than E-CFCs isolated from healthy persons and patients with MPN without molecular abnormalities. Finally, JAK2^V617F-positive E-CFCs exhibited a high proficiency to adhere to normal mononuclear cells. This study highlights a novel mechanism underlying the thrombophilia observed in MPN.

Purpose Polycythemia vera (PV) and essential thrombocythemia (ET) can present in pediatric age as sporadic or familial diseases. To define the biologic profile of childhood PV and ET, we evaluated specific markers in a cohort of pediatric patients affected by PV and ET, including cases with familial occurrence. Patients and Methods Thirty-eight children with PV and ET were investigated. The control group included 58 adults with PV and ET. Endogenous erythroid colonies, qualitative reverse transcriptase polymerase chain reaction for polycythemia rubra vera-1 (PRV-1) RNA expression, human androgen receptor assay and allele specific polymerase chain reaction for JAK2 V617F mutation were undertaken in all patients. Thrombopoietin, thrombopoietin receptor (c-mpl), and erythropoietin receptor mutation analysis was performed by direct sequencing in familial cases. Results The JAK2 V617F mutation in children with PV was significantly less frequent than in adult PV. The most common myeloproliferative marker found in these patients was PRV-1 RNA overexpression. Children and adults with sporadic ET showed a similar proportion of patients with PRV-1 RNA overexpression, JAK2 V617F mutation, and clonality, while none of the familial ET showed JAK2 V617F mutation and clonality. Also, PRV-1 RNA overexpression was significantly less common. Furthermore, most patients with familial ET exhibited the dominant-positive activating mutation of c-mpl. Finally, children with PV and ET had a significant lower incidence of thrombosis than adults. Conclusion This study demonstrates that familial and sporadic ET recognize different pathogenetic mechanisms. Myeloproliferative markers are specific tests for the diagnosis of ET in children with sporadic forms, while a significant proportion of children with PV can prove negative.

Purpose: The Epstein–Barr virus (EBV) is present in the malignant Hodgkin/Reed–Sternberg (HRS) cells of 20% to 40% cases of Hodgkin lymphoma (HL) in Western countries. We were interested in the detection and quantification of cell-free plasma EBV-DNA as an indicator of biological and clinical characteristics in EBV-associated HL. Experimental Design: EBV was detected in peripheral blood compartments (whole blood, plasma, and mononuclear cells) at diagnosis by real-time PCR for the EBNA (EB nuclear antigen) region (n = 93) and in HRS cells by in situ hybridization for EBV-encoded small RNAs (EBER; n = 63). These data were correlated to histological and clinical characteristics, EBV serology, circulating cell-free DNA, and interleukin (IL)-6 levels. Results: Detection of EBV-DNA in plasma had a high specificity (90%), but a relatively low sensitivity (65%) to predict for EBV association. The viral load was higher in patients with advanced stage disease, older age in the presence of B-symptoms, and international prognostic score more than 2. The presence of EBV in HRS cells and higher plasma EBV-DNA copy numbers correlated to an increased frequency of tumor-infiltrating CD68+ macrophages in lymph node biopsies. Plasma EBV-DNA load correlated to circulating cell-free DNA and IL-6 levels, and inversely correlated to lymphocyte counts and EBNA1 antibody titers. Conclusion: Although the presence of EBV-DNA in peripheral blood cannot be regarded as a surrogate marker for EBER, the plasma EBV-DNA load at HL diagnosis is an indicator of disease activity and biological characteristics associated with negative prognosis. Moreover, the inverse correlation to EBNA1 antibody titers and lymphocyte counts may indicate a reduction in immunosurveillance, favoring the expansion of EBV-HRS cells in HL. Clin Cancer Res; 17(9); 2885–92. ©2011 AACR.

Background The MPLSer505Asn mutation has been reported to be a cause of hereditary thrombocythemia. Recently, we detected this mutation in a large proportion of children with familial thrombocythemia, suggesting that in Italy the incidence of MPLSer505Asn mutation could be underestimated.Design and Methods We extended the search for this mutation to all patients with essential thrombocythemia who had a positive family history for thrombocytosis or essential thrombocythemia. We identified eight Italian families positive for the MPLSer505Asn mutation. Clinical and hematologic data were available for members of seven families, including 21 patients with a proven mutation and 20 relatives with thrombocytosis.Results Fifteen major thrombotic episodes, nine of which were fatal, were recorded among 41 patients. The thrombotic manifestation was stroke in four cases, myocardial infarction in seven cases, fetal loss in two cases, deep vein thrombosis of the leg in one case and Budd Chiari syndrome in one case. Almost all patients over 20 years old had splenomegaly and bone marrow fibrosis, while these were rarely observed in patients under 20 years old, suggesting that these manifestations are associated with aging. Finally, the life expectancy of family members with thrombocytosis was significantly shorter than that of members without thrombocytosis (P=0.003).Conclusions Patients with familial thrombocytosis caused by a MPLSer505Asn mutation have a high risk of thrombosis and, with aging, develop splenomegaly and bone marrow fibrosis, significantly affecting their life expectancy.