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Moccia F.,Laboratory of General Physiology | Poletto V.,Unit of Clinical Epidemiology and Center for the Study of Myelofibrosis
Biochimica et Biophysica Acta - Molecular Cell Research | Year: 2015

Endothelial progenitor cells (EPCs) may be recruited from bone marrow to sustain the metastatic switch in a number of solid cancers, including breast cancer (BC) and renal cellular carcinoma (RCC). Preventing EPC mobilization causes tumor shrinkage. Novel anti-angiogenic treatments have been introduced in therapy to inhibit VEGFR-2 signaling; unfortunately, these drugs blocked tumor angiogenesis in pre-clinical murine models, but resulted far less effective in human patients. Understanding the molecular mechanisms driving EPC proliferation and tubulogenesis in cancer patients could outline novel targets for alternative anti-angiogenic treatments. Store-operated Ca2+ entry (SOCE) regulates the growth of human EPCs, and it is mediated by the interaction between the endoplasmic reticulum Ca2+-sensor, Stim1, and the plasmalemmal Ca2+ channels, Orai1 and TRPC1. EPCs do not belong to the neoplastic clone: thus, unlike tumor endothelium and neoplastic cells, they should not remodel their Ca2+ toolkit in response to tumor microenvironment. However, our recent work demonstrated that EPCs isolated from naïve RCC patients (RCC-EPCs) undergo a dramatic remodeling of their Ca2+ toolkit by displaying a remarkable drop in the endoplasmic reticulum Ca2+ content, by down-regulating the expression of inositol-1,4,5-receptors (InsP3Rs), and by up-regulating Stim1, Orai1 and TRPC1. Moreover, EPCs are dramatically less sensitive to VEGF stimulation both in terms of Ca2+ signaling and of gene expression when isolated from tumor patients. Conversely, the pharmacological abolition of SOCE suppresses proliferation in these cells. These results question the suitability of VEGFR-2 as a therapeutically relevant target for anti-angiogenic treatments and hint at Orai1 and TRPC1 as more promising alternatives. This article is part of a Special Issue entitled: 13th European Symposium on Calcium. © 2014 Elsevier B.V. Source

Barbui T.,Ospedali Riuniti di Bergamo | Carobbio A.,Ospedali Riuniti di Bergamo | Finazzi G.,Ospedali Riuniti di Bergamo | Vannucchi A.M.,University of Florence | And 12 more authors.
Haematologica | Year: 2011

We tested the hypothesis that levels of pentraxin high sensitivity C-reactive protein and pentraxin 3 might be correlated with cardiovascular complications in patients with essential thrombocythemia and polycythemia vera. High sensitivity C-reactive protein and pentraxin 3 were measured in 244 consecutive essential thrombocythemia and polycythemia vera patients in whom, after a median follow up of 5.3 years (range 0-24), 68 cardiovascular events were diagnosed. The highest C-reactive protein tertile was compared with the lowest (>3 vs. <1 mg/L) and correlated with age (P=0.001), phenotype (polycythemia vera vs. essential thrombocythemia, P=0.006), cardiovascular risk factors (P=0.012) and JAK2V617F allele burden greater than 50% (P=0.003). Major thrombosis rate was higher in the highest C-reactive protein tertile (P=0.01) and lower at the highest pentraxin 3 levels (P=0.045). These associations remained significant in multivariate analyses and indicate that blood levels of high sensitivity C-reactive protein and petraxin 3 independently and in opposite ways modulate the intrinsic risk of cardiovascular events in patients with myeloproliferative disorders & copy 2011 Ferrata Storti Foundation. Source

Rosti V.,Unit of Clinical Epidemiology and Center for the Study of Myelofibrosis | Bonetti E.,Unit of Clinical Epidemiology and Center for the Study of Myelofibrosis | Bergamaschi G.,Foundation Medicine | Campanelli R.,Unit of Clinical Epidemiology and Center for the Study of Myelofibrosis | And 11 more authors.
PLoS ONE | Year: 2010

Increased mobilization of circulating endothelial progenitor cells may represent a new biological hallmark of myeloproliferative neoplasms. We measured circulating endothelial colony forming cells (ECFCs) in 106 patients with primary myelofibrosis, fibrotic stage, 49 with prefibrotic myelofibrosis, 59 with essential thrombocythemia or polycythemia vera, and 43 normal controls. Levels of ECFC frequency for patient's characteristics were estimated by using logistic regression in univariate and multivariate setting. The sensitivity, specificity, likelihood ratios, and positive predictive value of increased ECFC frequency were calculated for the significantly associated characteristics. Increased frequency of ECFCs resulted independently associated with history of splanchnic vein thrombosis (adjusted odds ratio = 6.61, 95% CI = 2.54- 17.16), and a summary measure of non-active disease, i.e. hemoglobin of 13.8 g/dL or lower, white blood cells count of 7.8x10 9/L or lower, and platelet count of 400x10 9/L or lower (adjusted odds ratio = 4.43, 95% CI = 1.45-13.49) Thirteen patients with splanchnic vein thrombosis non associated with myeloproliferative neoplasms were recruited as controls. We excluded a causal role of splanchnic vein thrombosis in ECFCs increase, since no control had elevated ECFCs. We concluded that increased frequency of ECFCs represents the biological hallmark of a non-active myeloproliferative neoplasm with high risk of splanchnic vein thrombosis. The recognition of this disease category copes with the phenotypic mimicry of myeloproliferative neoplasms. Due to inherent performance limitations of ECFCs assay, there is an urgent need to arrive to an acceptable standardization of ECFC assessment. © 2010 Rosti et al. Source

Balduini A.,University of Pavia | Balduini A.,Tufts University | Badalucco S.,University of Pavia | Pugliano M.T.,University of Milan | And 5 more authors.
PLoS ONE | Year: 2011

Background: Ph-negative myeloproliferative neoplasms (MPNs) are clonal disorders that include primary myelofibrosis (PMF), polycythemia vera (PV) and essential thrombocythemia (ET). Although the pathogenesis of MPNs is still incompletely understood, an involvement of the megakaryocyte lineage is a distinctive feature. Methodology/Principal Findings: We analyzed the in vitro megakaryocyte differentiation and proplatelet formation in 30 PMF, 8 ET, 8 PV patients, and 17 healthy controls (CTRL). Megakaryocytes were differentiated from peripheral blood CD34+ or CD45+ cells in the presence of thrombopoietin. Megakaryocyte output was higher in MPN patients than in CTRL with no correlation with the JAK2 V617F mutation. PMF-derived megakaryocytes displayed nuclei with a bulbous appearance, were smaller than ET- or PV-derived megakaryocytes and formed proplatelets that presented several structural alterations. In contrast, ET- and PV-derived megakaryocytes produced more proplatelets with a striking increase in bifurcations and tips compared to both control and PMF. Proplatelets formation was correlated with platelet counts in patient peripheral blood. Patients with pre-fibrotic PMF had a pattern of megakaryocyte proliferation and proplatelet formation that was similar to that of fibrotic PMF and different from that of ET. Conclusions/Significance: In conclusion, MPNs are associated with high megakaryocyte proliferative potential. Profound differences in megakaryocyte morphology and proplatelet formation distinguish PMF, both fibrotic and prefibrotic, from ET and PV. © 2011 Balduini et al. Source

Barosi G.,Unit of Clinical Epidemiology and Center for the Study of Myelofibrosis | Poletto V.,Unit of Clinical Epidemiology and Center for the Study of Myelofibrosis | Massa M.,Biotechnology Research Area | Campanelli R.,Unit of Clinical Epidemiology and Center for the Study of Myelofibrosis | And 6 more authors.
PLoS ONE | Year: 2013

Purpose: The influence of JAK2 V617F mutation on blast transformation (BT) and overall survival (OS) in primary myelofibrosis (PMF) is controversial. In a large cohort of patients we applied competing risks analysis for studying the influence of JAK2V617F mutation on BT in PMF. Patients and Methods: In 462 PMF-fibrotic type patients (bone marrow [BM] fibrosis grade >0) we computed the incidence of BT and death in the framework of Cox regression analysis and of Fine and Gray competing risks analysis for BT. Results: At the Cox regression analysis, having either a wild-type (wt) or a homozygous JAK2V617F genotype were factors for BT (HR, 1.98 and 2.04, respectively, with respect to the heterozygous genotype), but not for OS. At the competing risks regression analysis, the risk for BT in wt and homozygous V617F patients increased with respect to Cox analysis, giving a sHR of 2.17 and 2.12, respectively. Correcting the results for the variables that could have influence on BT, JAK2V617F wt and homozygous genotypes remained independently associated with BT. In a validation cohort of 133 independent cases with PMF-prefibrotic type (BM fibrosis grade = 0), the BT predictive model including JAK2V617F genotype and older age retained high discriminant capacity (C statistics, 0.70; 95% CI, 0.47 to 0.92). Conclusion: The accumulation of mutated alleles in the JAK2V617F clone or the selective acquisition of a proliferative advantage in the wt clone are two relevant routes to BT in PMF. The influence of these results on treatment decisions with anti-JAK2 agents should be tested. © 2013 Barosi et al. Source

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