Altered erythropoiesis and decreased number of erythrocytes in children with neuroblastoma.

Neuroblastoma (NB) is a pediatric tumor presenting at diagnosis either as localized or metastatic disease, which mainly involves the bone marrow (BM). The physical occupancy of BM space by metastatic NB cells has been held responsible for impairment of BM function. Here, we investigated whether localized or metastatic NB may alter hematopoietic lineages' maturation and release of mature cells in the periphery, through gene expression profiling, analysis of BM smears, cell blood count and flow cytometry analysis. Gene ontology and disease-associated analysis of the genes significantly under-expressed in BM resident cells from children with localized and metastatic NB, as compared to healthy children, indicated anemia, blood group antigens, and heme and porphyrin biosynthesis as major functional annotation clusters. Accordingly, in children with NB there was a selective impairment of erythrocyte maturation at the ortho-chromic stage that resulted in reduced erythrocyte count in the periphery, regardless of the presence of metastatic cells in the BM. By considering all NB patients, low erythrocyte count at diagnosis associated with worse survival. Moreover, in the subset of metastatic patients, low erythrocyte count, hemoglobin and hematocrit and high red cell distribution width at follow-up also associated with worse outcome. These observations provide an alternative model to the tenet that infiltrating cells inhibit BM functions due to physical occupancy of space and may open a new area of research in NB to understand the mechanism(s) responsible for such selective impairment.

Clinical Effects of Driver Somatic Mutations on the Outcomes of Patients With Myelodysplastic Syndromes Treated With Allogeneic Hematopoietic Stem-Cell Transplantation.

PURPOSE: The genetic basis of myelodysplastic syndromes (MDS) is heterogeneous, and various combinations of somatic mutations are associated with different clinical phenotypes and outcomes. Whether the genetic basis of MDS influences the outcome of allogeneic hematopoietic stem-cell transplantation (HSCT) is unclear. PATIENTS AND METHODS: We studied 401 patients with MDS or acute myeloid leukemia (AML) evolving from MDS (MDS/AML). We used massively parallel sequencing to examine tumor samples collected before HSCT for somatic mutations in 34 recurrently mutated genes in myeloid neoplasms. We then analyzed the impact of mutations on the outcome of HSCT. RESULTS: Overall, 87% of patients carried one or more oncogenic mutations. Somatic mutations of ASXL1, RUNX1, and TP53 were independent predictors of relapse and overall survival after HSCT in both patients with MDS and patients with MDS/AML (P values ranging from .003 to .035). In patients with MDS/AML, gene ontology (ie, secondary-type AML carrying mutations in genes of RNA splicing machinery, TP53-mutated AML, or de novo AML) was an independent predictor of posttransplantation outcome (P = .013). The impact of ASXL1, RUNX1, and TP53 mutations on posttransplantation survival was independent of the revised International Prognostic Scoring System (IPSS-R). Combining somatic mutations and IPSS-R risk improved the ability to stratify patients by capturing more prognostic information at an individual level. Accounting for various combinations of IPSS-R risk and somatic mutations, the 5-year probability of survival after HSCT ranged from 0% to 73%. CONCLUSION: Somatic mutation in ASXL1, RUNX1, or TP53 is independently associated with unfavorable outcomes and shorter survival after allogeneic HSCT for patients with MDS and MDS/AML. Accounting for these genetic lesions may improve the prognostication precision in clinical practice and in designing clinical trials.

Soluble HLA-G and HLA-E Levels in Bone Marrow Plasma Samples Are Related to Disease Stage in Neuroblastoma Patients.

The role of nonclassical HLA-class Ib molecules HLA-G and HLA-E in the progression of Neuroblastoma (NB), the most common pediatric extracranial solid tumor, has been characterized in the last years. Since BM infiltration by NB cells is an adverse prognostic factor, we have here analyzed for the first time the concentration of soluble (s)HLA-G and HLA-E in bone marrow (BM) plasma samples from NB patients at diagnosis and healthy donors. sHLA-G and sHLA-E are present in BM plasma samples, and their levels were similar between NB patients and controls, thus suggesting that these molecules are physiologically released by resident or stromal BM cell populations. This hypothesis was supported by the finding that sHLA-G and sHLA-E levels did not correlate with BM infiltration and other adverse prognostic factors (MYCN amplification and age at diagnosis). In contrast, BM plasma levels of both molecules were higher in patients with metastatic disease than in patients with localized NB, thus suggesting that concentration of these molecules might be correlated with disease progression. The prognostic role of sHLA-G and sHLA-E concentration in the BM plasma for NB patients will be evaluated in future studies, by analyzing the clinical outcome of the same NB patients at follow-up.

Wilms Tumor 1 Expression and Pre-emptive Immunotherapy in Patients with Acute Myeloid Leukemia Undergoing an Allogeneic Hemopoietic Stem Cell Transplantation.

Minimal residual disease (MRD) was monitored by Wilms tumor 1 (WT1) expression in 207 patients with acute myeloid leukemia (AML) after an allogeneic hemopoietic stem cell transplantation (HSCT) as a trigger to initiate pre-emptive immunotherapy (IT) with cyclosporin discontinuation and/or donor lymphocyte infusion. The trigger for IT was WT1 ≥ 180 copies/10(4) Abelson cells in marrow cells in the first group of 122 patients (WT1-180) and ≥ 100 copies in a subsequent group of 85 patients (WT1-100). Forty patients received IT. The cumulative incidence (CI) of relapse was 76% in WT1-180 (n = 17) versus 29% in WT1-100 patients (n = 23) receiving IT (P = .006); the leukemia-free survival from MRD positivity was 23% versus 74%, respectively (P = .003). We then looked at the entire AML patient population (n = 207). WT1-180 and WT1-100 patients were comparable for disease phase and age. The overall 4-year CI of transplantation-related mortality was 13% in both groups; the CI of leukemia relapse was 38% in the WT1-180 and 28% in the WT1-100 patients (P = .05) and leukemia-free survival was 56% versus 48%, respectively (P = .07). In conclusion, we suggests that WT1-based pre-emptive immunotherapy is feasible in patients with undergoing an allogeneic HSCT. The protective effect on relapse is greater when IT is triggered at lower levels of WT1.

CD4+CD25hiCD127- Treg and CD4+CD45R0+CD49b+LAG3+ Tr1 cells in bone marrow and peripheral blood samples from children with neuroblastoma.

Metastatic spread in the bone marrow (BM) at diagnosis is the worst prognostic factor for neuroblastoma (NB) patients. Here, we analyzed the presence of two immunosuppressive cell subsets, CD4+CD25hiCD127- regulatory T (Treg) cells and CD4+CD45R0+CD49b+LAG3+ type 1 regulatory (Tr1) cells, in BM and peripheral blood (PB) samples from NB patients and controls. Frequency of both regulatory cell subsets was lower in BM and PB samples from NB patients than in respective healthy controls. No correlation was found between the frequency of Treg and Tr1 cells and prognostic factors at diagnosis, such as age and stage. Only MYCN amplification correlated to a higher number of Treg in BM and of Tr1 in PB. These findings suggested an altered trafficking of regulatory T cells in NB, but delineated a limited role of these subsets in BM microenvironment and/or periphery in NB. These observations should be considered designing immunotherapeutic approaches for metastatic NB.

Improved Outcome of Alternative Donor Transplantations in Patients with Myelofibrosis: From Unrelated to Haploidentical Family Donors.

This is a retrospective analysis of 95 patients with myelofibrosis who were allografted between 2001 and 2014. The aims of the study were to assess whether the outcome of alternative donor grafts has improved with time and how this compares with the outcome of identical sibling grafts. Patients were studied in 2 time intervals: 2000 to 2010 (n = 58) and 2011 to 2014 (n = 37). The Dynamic International Prognostic Scoring System score was comparable in the 2 time periods, but differences in the most recent group included older age (58 versus 53 years, P = .004), more family haploidentical donors (54% versus 5%, P < .0001), and the introduction of the thiotepa-fludarabine-busulfan conditioning regimen (70% of patients versus 2%, P < .0001). Acute and chronic graft-versus-host disease were comparable in the 2 time periods. The 3-year transplantation-related mortality (TRM) in the 2011 to 2014 period versus the 2000 to 2010 period is 16% versus 32% (P = .10), the relapse rate 16% versus 40% (P = .06), and actuarial survival 70% versus 39% (P = .08). Improved survival was most pronounced in alternative donor grafts (69% versus 21%, P = .02), compared with matched sibling grafts (72% versus 45%, P = .40). In conclusion, the outcome of allografts in patients with myelofibrosis has improved in recent years because of a reduction of both TRM and relapse. Improvement is most significant in alternative donor transplantations, with modifications in donor type and conditioning regimen.

CD34 selected cells for the treatment of poor graft function after allogeneic stem cell transplantation.

Poor graft function (PGF) is characterized by pancytopenia and a hypoplastic marrow, with complete donor chimerism, usually without severe graft-versus-host disease (GVHD). We report 41 patients with PGF, treated with granulocyte colony-stimulating factor-mobilized CD34 selected cells, at a median interval from transplant of 140 days, without conditioning and without GVHD prophylaxis. Donors were HLA matched siblings (n = 12), unrelated donors (n = 18), or mismatched family members (n = 11). The median number of infused CD34(+) cells was 3.4 × 10(6)/kg. The rate of trilineage recovery was 75%: 83% for HLA matched siblings and 72% for unrelated and mismatched family members (P = .3). The cumulative incidence of acute grade II GVHD was 15%, and no patient developed de novo chronic GVHD. The actuarial 3-year survival is 63%: 76% and 25% for patients with or without trilineage recovery. These data confirm the role of CD34(+) selected cells from the same donor in the treatment of PGF and warrant the request for a second donation also when the donor is unrelated.

Leukaemia relapse after allogeneic transplants for acute myeloid leukaemia: predictive role of WT1 expression.

We assessed WT1 expression (expressed as messenger copies/10(4) ABL1) from marrow cells of 122 patients with acute myeloid leukaemia (AML), before and after an unmanipulated allogeneic haemopoietic stem cell transplant (HSCT). The median age was 44 years (15-69), 59% were in first remission, 74% received a myeloablative conditioning regimen and the median follow up was 865 d (34-2833). Relapse was higher in 67 patients with WT1 expression, at any time post-HSCT, exceeding 100 copies (54%), as compared to 16%, for 55 patients with post-HSCT WT1 expression <100 copies (P < 0·0001). Similarly, actuarial 5-year survival (OS) was 40% vs. 63%, respectively (P = 0·03). In multivariate Cox analysis, WT1 expression post-HSCT was the strongest predictor of relapse (Hazard Ratio [HR] 4·5, P = 0·0001), independent of disease phase (HR 2·3, P = 0·002). Donor lymphocyte infusions (DLI) were given to 17 patients because of increasing WT1 levels: their OS was 44%, vs. 14% for 21 patients with increasing WT1 expression who did not receive DLI (P = 0·004). In conclusion, WT1 expression post-HSCT is a strong predictor of leukaemia relapse and survival in AML; WT1 may be used as a marker for early interventional therapy.

Differential effects of the type of iron chelator on the absolute number of hematopoietic peripheral progenitors in patients with ß-thalassemia major.

Several studies have established an association between iron chelation therapy with deferasirox and hematopoietic improvement in patients with myelodysplastic syndromes. There are no data from patients with ß-thalassemia major. In a cross-sectional study, we evaluated the absolute number of several hematopoietic peripheral progenitors (colony-forming unit-granulocyte/macrophage, erythroid burst-forming units, colony-forming unit-granulocyte/erythrocyte/macrophage/megakaryocyte, and long-term culture-initiating cells) in 30 patients with ß-thalassemia major (median age 29.5 years, 40% males) and 12 age-matched controls. For the ß-thalassemia major patients, data on splenectomy status, the type of iron chelator used, and serum ferritin levels reflecting changes in iron status on the chelator were also retrieved. All patients had to be using the same iron chelator for at least 6 months with >80% compliance. The absolute number of all hematopoietic peripheral progenitors was higher in ß-thalassemia major patients than in controls, and varied between splenectomized and non-splenectomized patients (lower number of erythroid burst-forming units and higher numbers of colony-forming unit-granulocyte/macrophage, colony-forming unit-granulocyte/erythrocyte/macrophage/megakaryocyte, and long-term culture-initiating cells). The number of erythroid burst-forming units was significantly higher in patients taking deferasirox (n=10) than in those taking either deferoxamine (n=10) or deferiprone (n=10) (P<0.05). After adjusting for age, sex, splenectomy status, and serum ferritin changes, the association between a higher absolute number of erythroid burst-forming units in deferasirox-treated patients than in patients taking deferoxamine or deferiprone remained statistically significant (P=0.011). In conclusion, in ß-thalassemia major patients, compared with other iron chelators, deferasirox therapy is associated with higher levels of circulating erythroid burst-forming units. This variation is independent of iron status changes and is more likely to be due to the type of chelator.

Endothelial colony-forming cells from patients with chronic myeloproliferative disorders lack the disease-specific molecular clonality marker.

Two putative types of circulating endothelial progenitor cells have been recently identified in vitro: (1) endothelial colony-forming cell (ECFC) and (2) colony-forming unit-endothelial cell (CFU-EC). Only the former is now recognized to belong to endothelial lineage. We have used the ECFC and CFU-EC assays to readdress the issue of the clonal relation between endothelial progenitor cells and hematopoietic stem cells in patients with Philadelphia-positive and Philadelphia-negative chronic myeloproliferative disorders. Both ECFCs and CFU-ECs were cultured from peripheral blood mononuclear cells, and either BCR-ABL rearrangement or JAK2-V617F mutation were assessed in both types of endothelial colonies. We found that ECFCs lack the disease-specific markers, which are otherwise present in CFU-ECs, thus reinforcing the concept that the latter belongs to the hematopoietic lineage, and showing that in chronic myeloproliferative disorders the cell that gives rise to circulating ECFC has a distinct origin from the cell of the hematopoietic malignant clone.

A novel Bim-BH3-derived Bcl-XL inhibitor: biochemical characterization, in vitro, in vivo and ex-vivo anti-leukemic activity.

BH3-only members of the Bcl-2 family exert a fundamental role in apoptosis induction. This work focuses on the development of a novel peptidic molecule based on the BH3 domain of Bim. The antiapoptotic molecule Bcl-X(L), involved in cancer development/progression and tumour resistance to cytotoxic drugs, is a target for Bim. According to a rational study of the structural interactions between wt Bim-BH3 and Bcl-X(L), we replaced specific residues of Bim-BH3 with natural and non-natural aminoacids and added an internalizing sequence, thus increasing dramatically the inhibitory activity of our modified Bim-BH3 peptide, called 072RB. Confocal microscopy and flow cytometry demonstrated cellular uptake and internalization of 072RB, followed by co-localization with mitochondria. Multiparameter flow cytometry demonstrated that the 072RB dose-dependent growth inhibition of leukaemia cell lines was due to apoptotic cell death. No effect was observed when cells were treated with the internalizing vector alone or a mutated control peptide (single aminoacid substitution L94A). Ex-vivo derived leukemic cells from acute myeloid leukaemia (AML) patients underwent cell death when cultured in vitro in the presence of 072RB. Conversely, no significant cytotoxic effect was observed when 072RB was administered to cultures of peripheral blood mononuclear cells, either resting or PHA-stimulated, and bone marrow cells of normal donors. Xenografts of human AML cells in NOD/SCID mice displayed a significant delay of leukemic cell growth upon treatment with 072RB administered intravenously (15 mg/Kg three times, 48 hours after tumour cell injection). Altogether, these observations support the therapeutic potentials of this novel BH3 mimetic.

Antileukemia effects of xanthohumol in Bcr/Abl-transformed cells involve nuclear factor-kappaB and p53 modulation.

The oncogenic Bcr-Abl tyrosine kinase activates various signaling pathways including phosphoinositide 3-kinase/Akt and nuclear factor-kappaB that mediate proliferation, transformation, and apoptosis resistance in Bcr-Abl+ myeloid leukemia cells. The hop flavonoid xanthohumol inhibits tumor growth by targeting the nuclear factor-kappaB and Akt pathways and angiogenesis. Here, we show that xanthohumol has in vitro activity against Bcr-Abl+ cells and clinical samples and retained its cytotoxicity when imatinib mesylate-resistant K562 cells were examined. Xanthohumol inhibition of K562 cell viability was associated with induction of apoptosis, increased p21 and p53 expression, and decreased survivin levels. We show that xanthohumol strongly inhibited Bcr-Abl expression at both mRNA and protein levels and show that xanthohumol caused elevation of intracellular reactive oxygen species and that the antioxidant N-acetylcysteine blunted xanthohumol-induced events. Further, we observed that xanthohumol inhibits leukemia cell invasion, metalloprotease production, and adhesion to endothelial cells, potentially preventing in vivo life-threatening complications of leukostasis and tissue infiltration by leukemic cells. As structural mutations and/or gene amplification in Bcr-Abl can circumvent an otherwise potent anticancer drug such as imatinib, targeting Bcr-Abl expression as well as its kinase activity could be a novel additional therapeutic approach for the treatment of Bcr-Abl+ myeloid leukemia.

Donor lymphocyte infusions for the treatment of minimal residual disease in acute leukemia / Infusão de linfócitos do doador para o tratamento da doença residual mínima

Minimal residual disease (MRD) was monitored in 80 patients with acute lymphoid (ALL, n=44) or myeloid (AML, n=36) leukemia, undergoing allogeneic haemopoietic stem cell transplantations. MRD markers were IgH-VDJ and TCR gene re-arrangement for ALL, and Wilm's Tumor (WT1) expression for AML. The overall cumulative incidence (CI) of MRD was positive in 45 percent and the CI of hematologic relapse was 24 percent (36 percent in MRD+ vs. 16 percent in MRD patients, p=0.03). The median interval from transplant to first MRD positivity was 120 days and to hematologic relapse 203 days. Patients were divided in 3 MRD groups: MRD (n=44), MRD+ given donor lymphocyte infusions (DLI) (n=17) and MRD+ not given DLI (n=19): leukemia relapse rates in these 3 groups were 16 percent, 6 percent and 63 percent, respectively (p<0.0001); the actuarial 3-year survival rates were 78 percent, 80 percent and 26 percent (p=0.001). In multivariate COX analysis, the MRD group was predictor of relapse (p<0.0001) and survival (p=0.01), together with disease phase and chronic graft versus host disease. In MRD+ patients, DLI protected against relapse (p=0.003) and improved survival (p=0.01). In conclusion, MRD positivity post-transplant predicts leukemia relapse: however, when MRD+ patients are given DLI, their outcomes are comparable to MRD- patients.

A doença residual mínima (DRM) foi monitorada em 80 pacientes com leucemia linfóide aguda (n=44) e mielóide aguda (n=36) que foram submetidos ao transplante alogênico de célula-tronco. Marcadores da DRM foram a IgH-VDJ e rearranjo do TCR para a LLA e expressão do Tumor de Wills (WT1) para LMA. A incidência acumulada global (IC) para a DRM foi positiva em 45 por cento e a IC para recaída hematológica foi 24 por cento (36 por cento na DRM+ versus 16 por cento na DRM-, p=0.03). O intervalo mediano entre o TMO e a primeira DRM positividade foi dia +120, e para a recaída hematológica, dia +203. Os pacientes puderam ser divididos em três grupos: DRM-(n=44), DRM+ onde foi dada a infusão de linfócitos do doador (ILD) (n=17) e DRM+ não dado ILD (n=19): a recidiva nos três grupos foi de 16 por cento, 6 por cento e 63 por cento, respectivamente (p<0.0001); a sobrevida em três anos foi 78 por cento, 80 por cento e 26 por cento (p=0.001). No modelo de Cox, o grupo de DRM foi preditor de recidiva (p<0.0001) e sobrevida global (p=0.01), juntamente com a fase da doença e a doença do enxerto contra o hospedeiro. Na DRM+, IDL protegeu contra a recidiva (p=0.003) e melhorou a sobrevida (p=0.01). Em conclusão, a positividade para a DRM pós-transplante prediz recidiva da leucemia. Entretanto, quando é dada a ILD ao paciente DRM+, a evolução destes pacientes é comparável aos pacientes DRM-.

Clinical scale ex vivo expansion of cord blood-derived outgrowth endothelial progenitor cells is associated with high incidence of karyotype aberrations.

OBJECTIVE: Endothelial progenitor cells (EPCs) are involved in neovessel formation. So far, therapeutic angiogenesis is hampered by the low frequency and limited proliferative potential of these cells isolated from peripheral blood. Recently, it has been shown that cord blood-derived EPCs (CB EPCs) can be ex vivo expanded on a clinical scale. In this study, we evaluated the expansion potential of CB EPCs together with their phenotypic, functional, and chromosomal stability over time. MATERIALS AND METHODS: Flow cytometry, in vitro tube formation, and proliferation assays were performed to characterize CB EPC-derived cells. Chromosomal stability was evaluated by karyotype analysis. In vitro and in vivo tumorigenicity was evaluated by soft agar assay and injection into nonobese diabetic/severe combined immunodeficient mice, respectively. RESULTS: We showed that CB EPC-derived cells displayed phenotypic and functional features of EPCs, although a process of maturation was observed over time. Although we confirmed that CB EPCs have a greater expansion potential compared to peripheral blood EPCS, we observed a high incidence of cytogenetic alterations (71%) in the expanded endothelial cell population, even at early times of culture. In two cases, spontaneous transformation in vitro was documented, but none of the samples tested showed tumorigenic potential in vivo. Conversely, no karyotype alterations have been observed on peripheral blood EPCs-derived cells. CONCLUSIONS: We confirm that CB represents a good source for clinical ex vivo expansion of EPCs. However, because of high frequency of karyotype alterations, these cells cannot be considered free of risk in clinical application.

Interaction of human mesenchymal stem cells with cells involved in alloantigen-specific immune response favors the differentiation of CD4+ T-cell subsets expressing a regulatory/suppressive phenotype.

BACKGROUND AND OBJECTIVES: Experimental evidence and preliminary clinical studies have demonstrated that human mesenchymal stem cells (MSC) have an important immune modulatory function in the setting of allogeneic hematopoietic stem cell (HSC) transplantation. We extended the evaluation of mechanisms responsible for the immune regulatory effect derived from the interaction of human MSC with cells involved in alloantigen-specific immune response in mixed lymphocyte culture (MLC). DESIGN AND METHODS: Dendritic cell (DC) differentiation, T- and natural killer (NK)-lymphocyte expansion, alloantigen-specific cytotoxic activity and differentiation of CD4+ T-cell subsets co-expressing CD25 and/or CTLA4 molecules were assessed, comparing the effect observed using third-party MSC with that obtained employing MSC autologous to the MLC responder. RESULTS: We found that human MSC strongly inhibit alloantigen-induced DC1 differentiation, down-regulate alloantigen-induced lymphocyte expansion, especially that of CD8+ T cells and of NK lymphocytes, decrease alloantigen-specific cytotoxic capacity mediated by either cytotoxic T lymphocytes or NK cells and favor the differentiation of CD4+ T-cell subsets co-expressing CD25 and/or CTLA4. More effective suppressive activity on MLC-induced T-cell activation was observed when MSC were third-party, rather than autologous, with respect to MLC-responder cells. INTERPRETATION AND CONCLUSIONS: Our results strongly suggest that MSC-mediated inhibition of alloantigen-induced DC1 differentiation and preferential activation of CD4+ CD25+ T-cell subsets with presumed regulatory activity represent important mechanisms contributing to the immunosuppressive activity of MSC. Collectively, these data provide immunological support for the use of MSC to prevent immune complications related to both HSC and solid organ transplantation and to the theory that MSC are universal suppressors of immune reactivity.