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Supplementary Materials Index from Gene Expression Profiling of Acute Myeloid Leukemia with Translocation t(8;16)(p11;p13) and MYST3-CREBBP Rearrangement Reveals a Distinctive Signature with a Specific Pattern of HOX Gene Expression

Supplementary Materials and Tables A and B from Gene Expression Profiling of Acute Myeloid Leukemia with Translocation t(8;16)(p11;p13) and MYST3-CREBBP Rearrangement Reveals a Distinctive Signature with a Specific Pattern of HOX Gene Expression

Acute myeloid leukemia (AML) with translocation t(8;16)(p11;p13) is an infrequent leukemia subtype with characteristic clinicobiological features. This translocation leads to fusion of MYST3 (MOZ) and CREBBP (CBP) genes, probably resulting in a disturbed transcriptional program of a myelomonocytic precursor. Nonetheless, its gene expression profile is unknown. We have analyzed the gene expression profile of 23 AML patients, including three with molecularly confirmed MYST3-CREBBP fusion gene, using oligonucleotide U133A arrays (Affymetrix). MYST3-CREBBP cases clustered together and clearly differentiated from samples with PML-RARα, RUNX1-RUNX1T1, and CBFβ-MYH11 rearrangements. The relative expression of 46 genes, selected according to their differential expression in the high-density array study, was analyzed by low-density arrays in an additional series of 40 patients, which included 7 MYST3-CREBBP AML cases. Thus, genes such as prolactin (PRL) and proto-oncogene RET were confirmed to be specifically overexpressed in MYST3-CREBBP samples whereas genes such as CCND2, STAT5A, and STAT5B were differentially underexpressed in this AML category. Interestingly, MYST3-CREBBP AML exhibited a characteristic pattern of HOX expression, with up-regulation of HOXA9, HOXA10, and cofactor MEIS1 and marked down-regulation of other homeobox genes. This profile, with overexpression of FLT3, HOXA9, MEIS1, AKR7A2, CHD3, and APBA2, partially resembles that of AML with MLL rearrangement. In summary, this study shows the distinctive gene expression profile of MYST3-CREBBP AML, with overexpression of RET and PRL and a specific pattern of HOX gene expression. (Cancer Res 2006; 66(14): 6947-54)

Asparaginase (ASP) is an essential component for the acute lymphoblastic leukemia (ALL) treatment, but toxicities, such as allergy, frequently limit its use. Although the potentially lower PEG-ASP formulation immunogenicity, few studies with conflicting results have compared the allergy incidence between Escherichia coli-ASP and PEG-ASP in the same protocol. We aimed at comparing the allergy incidence in children receiving native E. coli-ASP versus PEG-ASP within the same clinical protocol (Spanish Society of Pediatric Hematology and Oncology ALL-SEHOP-PETHEMA 2013). One hundred and twenty-six children (1-19 years) diagnosed with ALL from 2013 to 2020 were included. Patients in group 1 received a sequential scheme of native E. coli-ASP 10,000 IU/m2 intramuscularly (IM) followed by PEG-ASP 1000 IU/m2 IM. Patients in group 2 received PEG-ASP 1000 IU/m2 IM upfront. Clinical allergy incidence was compared between both groups. Serum ASP activity (SAA) was measured in a subgroup of patients, and silent inactivation was recorded. The cumulative incidence of clinical allergy was significantly higher in group 1 (native followed by PEG-ASP) than in group 2 (PEG-ASP upfront), 24.7% versus 4.1% (p = 0.0085). Adequate ASP activity was achieved with PEG-ASP 1000 IU/m2 dose in most patients (median SAA 412.5 and 453.0 IU/L at days 7 and 14). The incidence of silent inactivation in PEG-ASP upfront patients was very low. PEG-ASP-used upfront was associated with a lower incidence of clinical allergy than that observed in the sequential use of native E. coli-ASP followed by PEG-ASP. PEG-ASP at 1000 IU/m2 was effective in achieving enough ASP activity in most patients.

Contains fulltext : 248362.pdf (Publisher’s version ) (Open Access) INTRODUCTION: One-quarter of the relapses in children with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) occur very early (within 18 months, before completion of treatment), and prognosis in these patients is worse compared to cases that relapse after treatment has ended. METHODS: In this study, we performed a genomic analysis of diagnosis-relapse pairs of 12 children who relapsed very early, followed by a deep-sequencing validation of all identified mutations. In addition, we included one case with a good initial treatment response and on-treatment relapse at the end of upfront therapy. RESULTS: We observed a dynamic clonal evolution in all cases, with relapse almost exclusively originating from a subclone at diagnosis. We identified several driver mutations that may have influenced the outgrowth of a minor clone at diagnosis to become the major clone at relapse. For example, a minimal residual disease (MRD)-based standard-risk patient with ETV6-RUNX1-positive leukemia developed a relapse from a TP53-mutated subclone after loss of the wildtype allele. Furthermore, two patients with TCF3-PBX1-positive leukemia that developed a very early relapse carried E1099K WHSC1 mutations at diagnosis, a hotspot mutation that was recurrently encountered in other very early TCF3-PBX1-positive leukemia relapses as well. In addition to alterations in known relapse drivers, we found two cases with truncating mutations in the cohesin gene RAD21. CONCLUSION: Comprehensive genomic characterization of diagnosis-relapse pairs shows that very early relapses in BCP-ALL frequently arise from minor subclones at diagnosis. A detailed understanding of the therapeutic pressure driving these events may aid the development of improved therapies.

Simple Summary: Dysregulation of noncoding RNAs has been described in numerous types of cancers and it has been associated with oncogenic or tumor suppressor activities. However, the signature of clinically relevant noncoding RNAs in pediatric B-cell acute lymphoblastic leukemia is still poorly understood. In a search for long non-coding RNAs that characterize pediatric B-cell acute lymphoblastic leukemia, we found that the long non-coding RNA AL133346.1 and a neighbouring protein-coding mRNA (CCN2) were significantly over-expressed in leukemia samples compared to healthy bone marrow. Survival analysis showed that patients with high CCN2 expression had a significantly better prognosis. These data suggest that AL133346.1/CCN2 could be useful for discriminating subtypes of leukemia and that CCN2 expression could predict the prognosis of pediatric patients with B-cell acute lymphoblastic leukemia. Abstract: Pediatric acute B-cell lymphoblastic leukemia (B-ALL) constitutes a heterogeneous and aggressive neoplasia in which new targeted therapies are required. Long non-coding RNAs have recently emerged as promising disease-specific biomarkers for the clinic. Here, we identified pediatric B-ALL-specific lncRNAs and associated mRNAs by comparing the transcriptomic signatures of tumoral and non-tumoral samples. We identified 48 lncRNAs that were di erentially expressed between pediatric B-ALL and healthy bone marrow samples. The most relevant lncRNA/mRNA pair was AL133346.1/CCN2 (previously known as RP11-69I8.3/CTGF), whose expression was positively correlated and increased in B-ALL samples. Their di erential expression pattern and their strong correlation were validated in external B-ALL datasets (Therapeutically Applicable Research to Generate E ective Treatments, Cancer Cell Line Encyclopedia). Survival curve analysis demonstrated that patients with “high” expression levels of CCN2 had higher overall survival than those with “low” levels (p = 0.042), and this gene might be an independent prognostic biomarker in pediatric B-ALL. These findings provide one of the first detailed descriptions of lncRNA expression profiles in pediatric B-ALL and indicate that these potential biomarkers could help in the classification of leukemia subtypes and that CCN2 expression could predict the survival outcome of pediatric B-cell acute lymphoblastic leukemia patients., Aula de Investigación sobre la Leucemia infantil: Héroes contra la Leucemia the Ministry of Economy of Spain SAF2015-67919-R, Junta de Andalucía PIGE-0440-2019 Pl-0245-2017 PI-0135-2020, University of Granada PPJIA2019-06 B-CTS-126-UGR18, Spanish Association for Cancer Research (LAB-AECC), Spanish Ministry of Education, Culture and Sports FPU fellowship FPU17/00067 FPU17/01258, PhD "La Caixa Foundation" fellowship LCF/BQ/DE15/10360019, Marie Sklodowska Curie Actions postdoctoral fellowship (H2020-MSCA-IF-2018), "Fundacion Benefica Anticancer Santa Candida y San Francisco Javier" predoctoral fellowship

The development of Next-Generation Sequencing (NGS) has provided useful diagnostic, prognostic, and therapeutic strategies for individualized management of B-cell precursor acute lymphoblastic leukemia (BCP-ALL) patients. Consequently, NGS is rapidly being established in clinical practice. However, the technology’s complexity, bioinformatics analysis, and the different available options difficult a broad consensus between different laboratories in its daily routine introduction. This collaborative study among Spanish centers was aimed to assess the feasibility, pros, and cons of our customized panel and other commercial alternatives of NGS-targeted approaches. The custom panel was tested in three different sequencing centers. We used the same samples to assess other commercial panels (OncomineTM Childhood Cancer Research Assay, Archer®FusionPlex® ALL, and Human Comprehensive Cancer Panel GeneRead Panel v2®). Overall, the panels showed a good performance in different centers and platforms, but each NGS approach presented some issues, as well as pros and cons. Moreover, a previous consensus on the analysis and reporting following international guidelines would be preferable to improve the concordance in results among centers. Our study shows the challenges posed by NGS methodology and the need to consider several aspects of the chosen NGS-targeted approach and reach a consensus before implementing it in daily practice.

B-cell acute lymphoblastic leukemia (ALL; B-ALL) is the most common pediatric cancer, and high hyperdiploidy (HyperD) identifies the most common subtype of pediatric B-ALL. Despite HyperD being an initiating oncogenic event affiliated with childhood B-ALL, the mitotic and chromosomal defects associated with HyperD B-ALL (HyperD-ALL) remain poorly characterized. Here, we have used 54 primary pediatric B-ALL samples to characterize the cellular-molecular mechanisms underlying the mitotic/chromosome defects predicated to be early pathogenic contributors in HyperD-ALL. We report that HyperD-ALL blasts are low proliferative and show a delay in early mitosis at prometaphase, associated with chromosome-alignment defects at the metaphase plate leading to robust chromosome-segregation defects and nonmodal karyotypes. Mechanistically, biochemical, functional, and mass-spectrometry assays revealed that condensin complex is impaired in HyperD-ALL cells, leading to chromosome hypocondensation, loss of centromere stiffness, and mislocalization of the chromosome passenger complex proteins Aurora B kinase (AURKB) and Survivin in early mitosis. HyperD-ALL cells show chromatid cohesion defects and an impaired spindle assembly checkpoint (SAC), thus undergoing mitotic slippage due to defective AURKB and impaired SAC activity, downstream of condensin complex defects. Chromosome structure/condensation defects and hyperdiploidy were reproduced in healthy CD34+ stem/progenitor cells upon inhibition of AURKB and/or SAC. Collectively, hyperdiploid B-ALL is associated with a defective condensin complex, AURKB, and SAC.

Treatment of pediatric acute leukemia might involve combined therapies targeting the FMS-like tyrosine kinase 3 (FLT3) receptor (i.e. quizartinib - AC220) and nucleotide metabolism (cytarabine - AraC). This study addressed the possibility of FLT3 modulating nucleoside salvage processes and, eventually, cytarabine action. Bone marrow samples from 108 pediatric leukemia patients (B-cell precursor acute lymphoblastic leukemia, BCP-ALL: 83; T-ALL: 9; acute myeloid leukemia, AML: 16) were used to determine the mRNA expression levels of FLT3, the cytarabine activating kinase dCK, and the nucleotidases cN-II and SAMHD1. FLT3 mRNA levels positively correlated with dCK, cN-II and SAMHD1 in the studied cohort. FLT3 inhibition using AC220 promoted the expression of cN-II in MV4-11 cells. Indeed, inhibition of cN-II with anthraquinone-2,6-disulfonic acid (AdiS) further potentiated the synergistic action of AC220 and cytarabine, at low concentrations of this nucleoside analog. FLT3 inhibition also down-regulated phosphorylated forms of SAMHD1 in MV4-11 and SEM cells. Thus, inhibition of FLT3 may also target the biochemical machinery associated with nucleoside salvage, which may modulate the ability of nucleoside-derived drugs. In summary, this contribution highlights the need to expand current knowledge on the mechanistic events linking tyrosine-kinase receptors, likely to be druggable in cancer treatment, and nucleotide metabolism, particularly considering tumor cells undergo profound metabolic reprogramming.

Relapsed/refractory T-cell acute lymphoblastic leukemia (T-ALL) has a dismal outcome, and no effective targeted immunotherapies for T-ALL exist. The extension of chimeric antigen receptor (CAR) T cells (CARTs) to T-ALL remains challenging because the shared expression of target antigens between CARTs and T-ALL blasts leads to CART fratricide. CD1a is exclusively expressed in cortical T-ALL (coT-ALL), a major subset of T-ALL, and retained at relapse. This article reports that the expression of CD1a is mainly restricted to developing cortical thymocytes, and neither CD34+ progenitors nor T cells express CD1a during ontogeny, confining the risk of on-target/off-tumor toxicity. We thus developed and preclinically validated a CD1a-specific CAR with robust and specific cytotoxicity in vitro and antileukemic activity in vivo in xenograft models of coT-ALL, using both cell lines and coT-ALL patient-derived primary blasts. CD1a-CARTs are fratricide resistant, persist long term in vivo (retaining antileukemic activity in re-challenge experiments), and respond to viral antigens. Our data support the therapeutic and safe use of fratricide-resistant CD1a-CARTs for relapsed/refractory coT-ALL. ispartof: BLOOD vol:133 issue:21 pages:2291-2304 ispartof: location:United States status: published

In intermediate-risk cytogenetic acute myeloid leukemia (IRC-AML) patients, novel biomarkers to guide post-remission therapy are needed. We analyzed with high-density arrays 40 IRC-AML patients who received a non-allogeneic hematopoietic stem-cell transplantation-based post-remission therapy, and identified a signature that correlated with early relapse. Subsequently, we analyzed selected 187 genes in 49 additional IRC-AML patients by RT-PCR. BAALC, MN1, SPARC and HOPX overexpression correlated to refractoriness. BAALC or ALDH2 overexpression correlated to shorter overall survival (OS) (5-year OS: 33 +/- 8.6% vs. 73.7 +/- 10.1%, p = .006; 32 +/- 9.3% vs. 66.4 +/- 9.7%, p = .016), whereas GPR44 or TP53INP1 overexpression correlated to longer survival (5-year OS: 66.7 +/- 10.3% vs. 35.4 +/- 9.1%, p = .04; 58.3 +/- 8.2% vs. 23.1 +/- 11.7%, p = .029). A risk-score combining these four genes expression distinguished low-risk and high-risk patients (5-year OS: 79 +/- 9% vs. 30 +/- 8%, respectively; p = .001) in our cohort and in an independent set of patients from a public repository. Our 4-gene signature may add prognostic information and guide post-remission treatment in IRC-AML patients.

Background Acute lymphoblastic leukemia (ALL) is the most frequent cancer in childhood. Although intensive chemotherapy has improved survival in those patients, important side effects, including hyperbilirubinemia, are frequent. Gilbert syndrome (GS) is a frequent condition that causes a reduction in glucuronidation and intermittent hyperbilirubinemia episodes. This could provoke a greater exposure to some cytotoxic agents used in ALL, increasing the risk of toxicity. On the other hand, unexplained hyperbilirubinemia could lead to unnecessary modifications or even treatment withdrawals, which could increase the risk of relapse, but data regarding this in ALL pediatric population are scarce. Methods Retrospective study to analyze toxicity, outcome and treatment modifications related to GS in children diagnosed with ALL. Results A total of 23 of 159 patients were diagnosed with GS. They had statistically higher hyperbilirubinemias during all treatment phases (P

Acute myeloid leukemia (AML) with myelodysplasia-related changes is characterized by the presence of multilineage dysplasia (MLD), frequently related to high-risk cytogenetics and poor outcome. However, the presence of MLD does not modify the favorable prognostic impact of NPM1 mutation. The prognosis of patients with AML presenting marked dysplasia lacking high-risk cytogenetics and NPM1 mutation is uncertain. We evaluated the prognostic impact of MLD in 177 patients with intermediate-risk cytogenetics AML (IR-AML) and wild-type NPM1. Patients were categorized as MLD-WHO (WHO myelodysplasia criteria; n = 43, 24 %), MLD-NRW (significant MLD non-reaching WHO criteria; n = 16, 9 %), absent MLD (n = 80, 45 %), or non-evaluable MLD (n = 38, 22 %). No differences concerning the main characteristics were observed between patients with or without MLD. Outcome of patients with MLD-WHO and MLD-NRW was similar, and significantly worse than patients lacking MLD. The presence of MLD (66 vs. 80 %, p = 0.03; HR, 95 % CI = 2.3, 1.08-4.08) and higher leukocyte count at diagnosis was the only variable associated with lower probability of complete remission after frontline therapy. Concerning survival, age and leukocytes showed an independent prognostic value, whereas MLD showed a trend to a negative impact (p = 0.087, HR, 95 % CI = 1.426, 0.95-2.142). Moreover, after excluding patients receiving an allogeneic stem cell transplantation in first CR, MLD was associated with a shorter survival (HR, 95 % CI = 1.599, 1.026-2.492; p = 0.038). In conclusion, MLD identifies a subgroup of patients with poorer outcome among patients with IR-AML and wild-type NPM1.

Introduction Human parainfluenza virus type 3 (HPIV-3) causes significant morbimortality in immunocompromised patients. Outbreaks of severe pneumonitis have been previously described in this setting. Materials and methods Retrospective observational study in children diagnosed with acute leukemia and a documented HPIV-3 infection in the context of a nosocomial outbreak occurred in a single center. Result During summer 2012, an HPIV-3 infection was detected in six hospitalized children with acute leukemia. All the patients had respiratory symptoms and one of them suffered from parotitis. Conclusion Early diagnoses using multiplex real-time polymerase chain reaction (PCR) let us control this outbreak. A phylogenetic analysis confirmed person-to-person transmission of a single HPIV-3 variant.

Supplemental Digital Content is available in the text, Objective: Several pieces of evidence indicate that HIV-infected adults undergo premature aging. The effect of HIV and antiretroviral therapy (ART) exposure on the aging process of HIV-infected children may be more deleterious since their immune system coevolves from birth with HIV. Design: Seventy-one HIV-infected (HIV+), 65 HIV-exposed-uninfected (HEU), and 56 HIV-unexposed-uninfected (HUU) children, all aged 0–5 years, were studied for biological aging and immune senescence. Methods: Telomere length and T-cell receptor rearrangement excision circle levels were quantified in peripheral blood cells by real-time PCR. CD4+ and CD8+ cells were analysed for differentiation, senescence, and activation/exhaustion markers by flow cytometry. Results: Telomere lengths were significantly shorter in HIV+ than in HEU and HUU children (overall, P

The association between seven polymorphisms in the genes hOCT1 and MDR1, encoding for imatinib transporter proteins, and the response to imatinib 400 mg/daily was investigated in 65 patients newly diagnosed with chronic-phase chronic myeloid leukemia. The AA genotype at the rs6935207 hOCT1 polymorphic locus was not detected in patients with inadequate response to imatinib. The CC genotype at the rs1045642 (C3435T) MDR1 locus was associated with primary failure, whereas a T allele at the rs2032582 (G2677T/A) MDR1 locus seemed to protect from primary failure. Beside, the MDR1 haplotype 1236T-2677G-3435C was more frequently found in patients primarily resistant to imatinib.

Resumen Fundamento y objetivo : La linfocitosis B policlonal persistente (LBPP) es una entidad muy poco frecuente que se relaciona con el tabaquismo e incide especialmente en mujeres. Cursa con aumento de IgM serica, asociacion al haplotipo HLA-DR7, anomalias citogeneticas y multiples reordenamientos de IgH/BCL-2 . Todavia no esta clara su naturaleza premaligna o benigna. El objetivo de este trabajo fue analizar las caracteristicas de la LBPP con especial interes en su evolucion. Pacientes y metodo Se han estudiado retrospectivamente 35 LBPP de 5 hospitales catalanes. Se realizo una valoracion morfologica de las extensiones de sangre por los miembros del Grup Catala de Citologia Hematologica (GCCH) en un microscopio de 16 cabezales y se analizaron los datos clinicos y biologicos. Resultados La LBPP se presento, en la mayoria de los casos, como linfocitosis en mujeres fumadoras. El distintivo morfologico es la presencia de linfocitos de aspecto activado, en ausencia de enfermedades viricas recientes, y de linfocitos bilobulados y/o hendidos, y algunos con bolsillos nucleares observados por ultraestructura. En la mayoria de los casos estudiados se detecto: aumento policlonal de IgM, expresion del haplotipo HLA-DR7, anomalias cromosomicas como i(3)(q10) y multiples reordenamientos de IgH/BCL-2 . Con una mediana de seguimiento de 70,7 meses, 34 de los 35 pacientes permanecen asintomaticos y vivos, uno fallecio por un adenocarcinoma de pulmon y otro desarrollo un linfoma folicular, sin demostracion de relacion alguna entre este y la LBPP. Conclusiones La LBPP presenta un curso estable y asintomatico, y se acompana con frecuencia de alteraciones geneticas. Se desconoce si es una situacion premaligna, a semejanza de las gammapatias monoclonales de significado incierto. Por ello, es fundamental una correcta interpretacion de la linfocitosis y un seguimiento evolutivo.

Pandemic influenza A (2009-H1N1) usually results in mild clinical illness, but in some individuals it can be life-threatening. There are no reports of this disease among paediatric patients with acute lymphoblastic leukaemia (ALL). We report ten consecutive patients with ALL and pandemic influenza treated in a single institution. Median age was 7 years (range: 3-12). All were treated with oseltamivir. There were no deaths. Two patients under intensive chemotherapy developed pneumonia and one required ventilatory support. ALL patients under maintenance treatment had mild disease. In conclusion, in our series only patients under intensive treatment developed a moderate to severe disease.

We studied a series of 68 subjects diagnosed with childhood acute myeloid leukemia (AML) using conventional cytogenetics and fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR) to analyze mutations in FLT3 and NPM1 genes, and/or array comparative genomic hybridization (CGH). Cytogenetic/FISH abnormalities were observed in 71% of subjects, FLT3-ITD mutations in 15%, and NPM1 mutations in 13%. The array CGH alterations (average 3.6 per case) were observed in 96% of the tested subjects. The most frequent alterations were gains of 8q24.3 and 11p15.5-p15.4 in 16% of the samples. Six genes (AKT1, RUNX1, LTB, SDC1, RUNX1T1, and JAK2) from the imbalanced regions have been reported to be involved in AML, whereas other 30 cancer genes, not previously reported in an AML context, were identified as imbalanced. They probably correspond to non passenger alterations that cooperate with the recurrent translocations. The clinical data and genetic changes were tested to find out the possible association with prognosis. Genomic instability (four or more genomic imbalances) was correlated with poor patient outcome (p = 0.029).

Aim To analyze toxicity, response and outcome of a phase II trial with intensive chemotherapy plus autologous stem-cell transplantation (ASCT) for young patients with peripheral T-cell lymphoma (PTCL). Patients and methods Forty-one patients [30 males and 11 females, median age 47 years] consecutively diagnosed with PTCL received three courses of high-dose cyclophosphamide 2000 mg/m2/day, adriamycin 90 mg/m2/day, vincristine and prednisone alternating with three courses of etoposide, cisplatin, cytarabine and prednisone. Responders were submitted to ASCT. Results Sixty-eight percent of patients received the planned treatment. After chemotherapy, 20 patients reached complete response (CR), 4 partial response and 17 failed. ASCT was carried out in 17 of 24 candidates due to lack of mobilization (three cases), toxicity (two), early relapse and patient decision (one each). CR rate after treatment was 51%. With a median follow-up of 3.2 years, 5 of 21 CR patients relapsed and 2 died in CR due to secondary neoplasms. Four-year progression-free survival was 30%. Twenty-two patients have died, with a 4-year overall survival of 39%. International Prognostic Index was the main variable predicting survival. No differences were seen among the 24 candidates according to whether or not they underwent ASCT. Conclusion This intensive regimen resulted in moderate CR rate, with manageable toxicity in PTCL. The contribution of ASCT in preventing relapse is debatable. Novel strategies to increase CR warrant investigation.

Conventional treatment of myelofibrosis includes a wait-and-see approach for asymptomatic patients, the use of oral cytolytic drugs such as hydroxyurea for the hyperproliferative forms of the disease, androgens or erythropoietin for anemia, and splenectomy in selected patients. Although these treatment modalities can improve quality of life, many patients do not respond, and the impact on survival is scant. This fact has stimulated the search for newer therapies for the disease. Antiangiogenic and immunomodulatory drugs such as thalidomide and lenalidomide have shown efficacy against anemia and thrombocytopenia but have frequent side effects. The combination of low-dose thalidomide with prednisone can also be effective and has a better tolerability. The therapeutic role of imatinib is limited, while tipifarnib, a farnesyltransferase inhibitor, has a modest effect in anemia and splenomegaly. Allogeneic stem cell transplantation (alloSCT) is the only curative therapy of myelofibrosis. AlloSCT with a standard conditioning regimen has an associated mortality rate of 30% and is indicated in younger patients with high-risk disease or resistance to conventional treatment. Because of its low mortality and curative potential, reduced-intensity conditioning alloSCT is being used in patients aged 45-70 years with high- or intermediate-risk myelofibrosis or resistance to treatment. Autologous SCT can be a palliative measure in patients without a suitable donor. The efficacy in myelofibrosis of newer immunomodulatory drugs, including pomalidomide, proteasome inhibitors, hypomethylating agents, and especially, Janus kinase 2 inhibitors, is currently being evaluated.

// Albert Catala 1, 2, 6 , Marcal Pastor-Anglada 3, 4, 6 , Liska Caviedes-Cardenas 3 , Roberta Malatesta 5 , Susana Rives 1, 2, 6 , Nerea Vega-Garcia 5 , Mireia Camos 2, 5, 6, * , Paula Fernandez-Calotti 3, 4, 6, * 1 Pediatric Hematology and Oncology Department, Hospital Sant Joan de Deu, University of Barcelona, Esplugues de Llobregat, Barcelona, Spain 2 National Biomedical Research Institute on Rare Diseases (CIBER ER), Instituto de Salud Carlos III, Madrid, Spain 3 Department of Biochemistry and Molecular Biology, University of Barcelona, Institute of Biomedicine (IBUB), Barcelona, Spain 4 Oncology Program, National Biomedical Research Institute of Liver and Gastrointestinal Diseases (CIBER EHD), Instituto de Salud Carlos III, Madrid, Spain 5 Hematology Laboratory, Hospital Sant Joan de Deu, University of Barcelona, Esplugues de Llobregat, Barcelona, Spain 6 Institut de Recerca Pediatrica Hospital Sant Joan de Deu (IRP-HSJD), Esplugues de Llobregat, Barcelona, Spain * Co-senior authors Correspondence to: Albert Catala, email: acatala@hsjdbcn.org Marcal Pastor-Anglada, email: mpastor@ub.edu Keywords: FLT3, Cytarabine, hENT1, nucleoside transporters, pediatric acute leukemia Received: November 04, 2015 Accepted: June 26, 2016 Published: July 06, 2016 ABSTRACT FLT3 abnormalities are negative prognostic markers in acute leukemia. Infant leukemias are a subgroup with frequent MLL (KMT2A) rearrangements, FLT3 overexpression and high sensitivity to cytarabine, but dismal prognosis. Cytarabine is transported into cells by Human Equilibrative Nucleoside Transporter-1 (hENT1, SLC29A1), but the mechanisms that regulate hENT1 in acute leukemia have been scarcely studied. We explored the expression and functional link between FLT3 and main cytarabine transporters in 50 pediatric patients diagnosed with acute lymphoblastic leukemia and MLL rearrangement (ALL-MLL+) and other subtypes of leukemia, and in leukemia cell lines. A significant positive correlation was found between FLT3 and hENT1 expression in patients. Cytarabine uptake into cells was mediated mainly by hENT1, hENT2 and hCNT1. hENT1-mediated uptake of cytarabine was transiently abolished by the FLT3 inhibitor PKC412, and this effect was associated with decreased hENT1 mRNA and protein levels. Noticeably, the cytotoxicity of cytarabine was lower when cells were first exposed to FLT3 inhibitors (PKC412 or AC220), probably due to decreased hENT1 activity, but we observed a higher cytotoxic effect if FLT3 inhibitors were administered after cytarabine. FLT3 regulates hENT1 activity and thereby affects cytarabine cytotoxicity. The sequence of administration of cytarabine and FLT3 inhibitors is important to maintain their efficacy.

Prieto et al., The MLL-AF4 (MA4) fusion gene is the genetic hallmark of an aggressive infant pro-B-acute lymphoblastic leukemia (B-ALL). Our understanding of MA4-mediated transformation is very limited. Whole-genome sequencing studies revealed a silent mutational landscape, which contradicts the aggressive clinical outcome of this hematologic malignancy. Only RAS mutations were recurrently detected in patients and found to be associated with poorer outcome. The absence of MA4-driven B-ALL models further questions whether MA4 acts as a single oncogenic driver or requires cooperating mutations to manifest a malignant phenotype. We explored whether KRAS activation cooperates with MA4 to initiate leukemia in cord blood-derived CD34(+) hematopoietic stem/progenitor cells (HSPC). Clonogenic and differentiation/proliferation assays demonstrated that KRAS activation does not cooperate with MA4 to immortalize CD34(+) HSPCs. Intrabone marrow transplantation into immunodeficient mice further showed that MA4 and KRASG12V alone or in combination enhanced hematopoietic repopulation without impairing myeloid-lymphoid differentiation, and that mutated KRAS did not cooperate with MA4 to initiate leukemia. However, KRAS activation enhanced extramedullary hematopoiesis of MA4-expressing cell lines and CD34(+) HSPCs that was associated with leukocytosis and central nervous system infiltration, both hallmarks of infant t(4;11)(+) B-ALL. Transcriptional profiling of MA4-expressing patients supported a cell migration gene signature underlying the mutant KRAS-mediated phenotype. Collectively, our findings demonstrate that KRAS affects the homeostasis of MA4-expressing HSPCs, suggesting that KRAS activation in MA4(+) B-ALL is important for tumor maintenance rather than initiation., This work was supported by the European Research Council (P. Menendez). The Spanish Ministry of Economy (ISCIII/FEDER-PI14/01119 to C. Bueno; SAF2013-43065-R to P. Menendez; and SAF2012-31627 to I. Varela), The Spanish Cancer Association (P. Menendez and C. Bueno), Fundacion Inocente (P. Menendez), and the Deutsche Jose Carreras Leukämie Stiftung (P. Menendez and R. Marschalek). C. Bueno is supported by a Miguel Servet contract (CPII13/00011). I. Varela is supported by Ramon Cajal Program. C. Prieto is supported by PFIS scholarship (FI12/00468). P. Menendez also acknowledges support from Obra Social La Caixa-Fundacio Josep Carreras and Generalitat de Catalunya (SGR330).

Acute leukemia is a clonal expansion of tumoral cells in bone marrow, blood or other tissues. The acute leukemias are classified as myeloid or lymphoid based on the lineage of the blast cells. Over the past three decades, remarkable advances have been made in the classification and treatment of acute leukemias. In the last years, the research into the molecular pathogenesis of acute leukemia has progressed. The knowledge of chromosomal translocations breakpoints and possible candidate oncogenes and tumor suppressor genes has allowed the integration of all these events into multistep cascades that impact specific signal transduction pathways and lead to leukemic transformation.

Acute myeloid leukemia (AML) with translocation t(8;16)(p11;p13) is an infrequent leukemia subtype with characteristic clinicobiological features. This translocation leads to fusion of MYST3 (MOZ) and CREBBP (CBP) genes, probably resulting in a disturbed transcriptional program of a myelomonocytic precursor. Nonetheless, its gene expression profile is unknown. We have analyzed the gene expression profile of 23 AML patients, including three with molecularly confirmed MYST3-CREBBP fusion gene, using oligonucleotide U133A arrays (Affymetrix). MYST3-CREBBP cases clustered together and clearly differentiated from samples with PML-RARα, RUNX1-RUNX1T1, and CBFβ-MYH11 rearrangements. The relative expression of 46 genes, selected according to their differential expression in the high-density array study, was analyzed by low-density arrays in an additional series of 40 patients, which included 7 MYST3-CREBBP AML cases. Thus, genes such as prolactin (PRL) and proto-oncogene RET were confirmed to be specifically overexpressed in MYST3-CREBBP samples whereas genes such as CCND2, STAT5A, and STAT5B were differentially underexpressed in this AML category. Interestingly, MYST3-CREBBP AML exhibited a characteristic pattern of HOX expression, with up-regulation of HOXA9, HOXA10, and cofactor MEIS1 and marked down-regulation of other homeobox genes. This profile, with overexpression of FLT3, HOXA9, MEIS1, AKR7A2, CHD3, and APBA2, partially resembles that of AML with MLL rearrangement. In summary, this study shows the distinctive gene expression profile of MYST3-CREBBP AML, with overexpression of RET and PRL and a specific pattern of HOX gene expression. (Cancer Res 2006; 66(14): 6947-54)

Purpose: The ZAP-70 gene is normally expressed in T and natural killer cells, where it is required for the T-cell receptor (TCR) signaling. More recently, it has been described that ZAP-70 contributes to the B-cell development at early stages of B-cell differentiation in mice. The purpose was to investigate the presence of ZAP-70 in normal pro/pre B cells and mature B cells and in tumoral cells from B-acute lymphoblastic leukemias (B-ALL). Experimental Design: ZAP-70 expression was ascertained by flow cytometry, immunofluorescence, Western blot, and quantitative reverse transcription-PCR. Analysis of ZAP-70 and other signaling proteins of the pre-TCR/TCR was done by Western blot. Results: ZAP-70 was expressed in pro/pre B cells but not in normal mature B cells derived from bone marrow, peripheral blood, or tonsil. Among tumoral cells, ZAP-70 was expressed in 56% of B-ALLs with pro/pre B-cell phenotype and in 4 of 6 Burkitt/ALL lymphomas. In B-ALL cells, expression of CD38 protein correlated with ZAP-70 expression (P = 0.05). Mutational analysis of the ZAP-70 gene revealed the absence of mutations in cases lacking ZAP-70 expression. Moreover, other elements of the pre-TCR/TCR signaling pathway, like LAT and Lck, were also found in B-ALL cells. Conclusions: Among normal B-cell subsets, ZAP-70 was found expressed in normal pro/pre B cells but not in a significant proportion of normal B cells with mature phenotype. Moreover, the presence of ZAP-70 in B-ALLs probably reflects their cellular origin. The lack of ZAP-70 expression in normal mature B cells suggests that its expression in mature-derived neoplasms with different cellular origin, such as Burkitt's lymphoma and chronic lymphocytic leukemia, might be due to an aberrant phenomenon.

Background: Different prognostic scores have been proposed to predict the outcome of follicular lymphoma (FL) patients at diagnosis. A new prognostic index specifically addressing FL patients, the Follicular Lymphoma International Prognostic Index (FLIPI), has recently been developed, which might also be useful in patients with progression. Patients and methods: One hundred and three patients (55 male, 48 female; median age 59 years) with FL in first relapse/progression after an initial response to therapy (50 complete responders/ 53 partial responders) were included in the study. Results: Five-year survival from progression (SFP) was 55% (95% confidence interval 44%-66%). The distribution according to the FLIPI at relapse was 39% good prognosis, 24% intermediate prognosis and 37% poor prognosis. Five-year SFP for these groups were 85%, 79% and 28%, respectively (P

The t(8;16)(p11;p13) fuses the MOZ (MYST3) gene at 8p11 with CBP (CREBBP) at 16p13 and is associated with an infrequent but well-defined type of acute myeloid leukemia (AML) that has unique morphocytochemical findings (monocytoid blast morphology with erythrophagocytosis and simultaneously positive for myeloperoxidase and nonspecific esterases). RT-PCR amplification of MOZ/CBP (MYST3/CREBBP) chimera has proved difficult, with four different transcripts found in four reported cases. We studied 7 AML-t(8;16) patients, 5 with cytogenetically demonstrated t(8;16) and 2 with similar morphocytochemical and immunophenotypical characteristics. Clinically, 3 cases presented as therapy-related leukemia. Extramedullar involvement was observed at presentation in 2 patients and coagulopathy in 4. The clinicobiological findings confirmed the distinctiveness of this entity. Of note is the erythrophagocytosis in 5 of 7 cases and the immunological negativity for CD34 and CD117 and positivity for CD56. Using a new RT-PCR strategy, we were able to amplify a specific band of 212 bp in six cases in which sequence analysis confirmed the presence of the previously described MOZ/CBP fusion transcript type I. This is the largest molecularly studied AML-t(8;16) series, which demonstrates that MOZ/CBP breakpoints are usually clustered in intron 16 of MOZ and intron 2 of CBP. The newly designed single-round PCR provides a simple tool for the molecular confirmation of MOZ/CBP rearrangement.

Imatinib mesylate (STI571) is a highly effective and well-tolerated treatment for patients with chronic-phase chronic myeloid leukaemia (CML), but information on its efficacy and tolerance in intensively pretreated patients is scarce. Thirty-three chronic-phase CML patients who were resistant or intolerant to interferon (IFN) and had been previously submitted to autologous stem cell transplantation were treated with imatinib for a median of 14 months (range: 6-19 months). Seven patients were in haematological response (HR) at the start of treatment; the remaining 26 attained a HR at a median of 3 weeks (range: 1-4 weeks). Major cytogenetic response rates at 3, 6 and 12 months were 42%, 45% and 55%, respectively, including 21%, 24% and 33% complete responses. Grade 3-4 neutropenia, thrombocytopenia and anaemia developed in 33%, 27% and 12% of patients respectively. Non-haematological toxicity included superficial oedema (21% of patients), gastrointestinal symptoms (18%), muscle cramps (15%), skin rash and liver enzyme increase (3% each). These results were not significantly different from those in 65 chronic-phase CML patients, resistant or intolerant to interferon without a previous ASCT, who were included in the same protocol. Imatinib mesylate is effective and safe in chronic-phase CML patients with a previous history of intensive treatment.