Martinez-Climent, J.A. (José Ángel)

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    A cyclin-D1 interaction with BAX underlies its oncogenic role and potential as a therapeutic target in mantle cell lymphoma
    (National Academy of Sciences, 2011-07-26) Fresquet, V. (Vicente); Beltran, E. (E.); Rieger, M. (Melissa); Lossos, I.S. (Izidore S.); Martinez-Climent, J.A. (José Ángel); Montes-Moreno, S. (Santiago); Gesk, S. (Stefan); Almada, L.L. (Luciana L.); Richter, J.A. (José Ángel); Raquel; Siebert, R. (Reiner); Sagardoy, A. (Ainara); Martinez-Useros, J. (Javier); Fernandez-Zapico, M.E. (Martín E.); Prosper-Cardoso, F. (Felipe); Calasanz-Abinzano, M.J. (Maria Jose); Piris, M.A. (Miguel A.); Sesma, I. (Izaskun)
    The chromosomal translocation t(11;14)(q13;q32) leading to cyclin-D1 overexpression plays an essential role in the development of mantle cell lymphoma (MCL), an aggressive tumor that remains incurable with current treatment strategies. Cyclin-D1 has been postulated as an effective therapeutic target, but the evaluation of this target has been hampered by our incomplete understanding of its oncogenic functions and by the lack of valid MCL murine models. To address these issues, we generated a cyclin-D1-driven mouse model in which cyclin-D1 expression can be regulated externally. These mice developed cyclin-D1-expressing lymphomas capable of recapitulating features of human MCL. We found that cyclin-D1 inactivation was not sufficient to induce lymphoma regression in vivo; however, using a combination of in vitro and in vivo assays, we identified a novel prosurvival cyclin-D1 function in MCL cells. Specifically, we found that cyclin-D1, besides increasing cell proliferation through deregulation of the cell cycle at the G(1)-S transition, sequestrates the proapoptotic protein BAX in the cytoplasm, thereby favoring BCL2's antiapoptotic function. Accordingly, cyclin-D1 inhibition sensitized the lymphoma cells to apoptosis through BAX release. Thus, genetic or pharmacologic targeting of cyclin-D1 combined with a proapoptotic BH3 mimetic synergistically killed the cyclin-D1-expressing murine lymphomas, human MCL cell lines, and primary lymphoma cells. Our study identifies a role of cyclin-D1 in deregulating apoptosis in MCL cells, and highlights the potential benefit of simultaneously targeting cyclin-D1 and survival pathways in patients with MCL. This effective combination therapy also might be exploited in other cyclin-D1-expressing tumors.
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    Preclinical activity of LBH589 alone or in combination with chemotherapy in a xenogeneic mouse model of human acute lymphoblastic leukemia.
    (Nature Publishing Group, 2012) Vilas, A. (Amaia); Cigudosa, J.C. (Juan Cruz); Roman-Gomez, J. (José); San-Jose-Eneriz, E. (Edurne); Blanco-Prieto, M.J. (María José); Garate, L. (Leire); Martinez-Climent, J.A. (José Ángel); Rifon, J. J. (Jose J.); Ribera, J.M. (José María); Miranda, E. (Estibaliz); Martino-Rodriguez, A. (Alba) de; Garcia-de-Jalon, J.A. (José A.); Prosper-Cardoso, F. (Felipe); Rio, P. (Paula); Segura, V. (Víctor); Calasanz-Abinzano, M.J. (Maria Jose); Aguirre-Ena, X. (Xabier); Abizanda-Sarasa, G. (Gloria); Martin-Subero, J.I. (Jose Ignacio); Moreno, C. (Cristina)
    Histone deacetylases (HDACs) have been identified as therapeutic targets due to their regulatory function in chromatin structure and organization. Here, we analyzed the therapeutic effect of LBH589, a class I-II HDAC inhibitor, in acute lymphoblastic leukemia (ALL). In vitro, LBH589 induced dose-dependent antiproliferative and apoptotic effects, which were associated with increased H3 and H4 histone acetylation. Intravenous administration of LBH589 in immunodeficient BALB/c-RAG2(-/-)γc(-/-) mice in which human-derived T and B-ALL cell lines were injected induced a significant reduction in tumor growth. Using primary ALL cells, a xenograft model of human leukemia in BALB/c-RAG2(-/-)γc(-/-) mice was established, allowing continuous passages of transplanted cells to several mouse generations. Treatment of mice engrafted with T or B-ALL cells with LBH589 induced an in vivo increase in the acetylation of H3 and H4, which was accompanied with prolonged survival of LBH589-treated mice in comparison with those receiving vincristine and dexamethasone. Notably, the therapeutic efficacy of LBH589 was significantly enhanced in combination with vincristine and dexamethasone. Our results show the therapeutic activity of LBH589 in combination with standard chemotherapy in pre-clinical models of ALL and suggest that this combination may be of clinical value in the treatment of patients with ALL.
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    Homozygous deletions localize novel tumor suppressor genes in B-cell lymphomas
    (American Society of Hematology, 2007) Marin, M. (Miguel); Fresquet, V. (Vicente); Beltran, E. (E.); Dyer, M.J.S. (Martin J. S.); Rosenwald, A. (Andreas); Pinkel, D. (Daniel); Karran, E.L. (E. L.); Martinez-Climent, J.A. (José Ángel); Richter, J.A. (José Ángel); Siebert, R. (Reiner); Mestre-Escorihuela, C. (Cinta); Marugan, I. (Isabel); Sanchez, L. (Lydia); Staudt, L.M. (Louis M.); Rubio-Moscardo, F. (Fanny); Climent, J. (Javier); Wheat, L.M. (Luise M.); Prosper-Cardoso, F. (Felipe); Aguirre-Ena, X. (Xabier); Sugimoto, K.J. (Kei-Ji); Garcia, J.F. (José Francisco)
    Integrative genomic and gene-expression analyses have identified amplified oncogenes in B-cell non-Hodgkin lymphoma (B-NHL), but the capability of such technologies to localize tumor suppressor genes within homozygous deletions remains unexplored. Array-based comparative genomic hybridization (CGH) and gene-expression microarray analysis of 48 cell lines derived from patients with different B-NHLs delineated 20 homozygous deletions at 7 chromosome areas, all of which contained tumor suppressor gene targets. Further investigation revealed that only a fraction of primary biopsies presented inactivation of these genes by point mutation or intragenic deletion, but instead some of them were frequently silenced by epigenetic mechanisms. Notably, the pattern of genetic and epigenetic inactivation differed among B-NHL subtypes. Thus, the P53-inducible PIG7/LITAF was silenced by homozygous deletion in primary mediastinal B-cell lymphoma and by promoter hypermethylation in germinal center lymphoma, the proapoptotic BIM gene presented homozygous deletion in mantle cell lymphoma and promoter hypermethylation in Burkitt lymphoma, the proapoptotic BH3-only NOXA was mutated and preferentially silenced in diffuse large B-cell lymphoma, and INK4c/P18 was silenced by biallelic mutation in mantle-cell lymphoma. Our microarray strategy has identified novel candidate tumor suppressor genes inactivated by genetic and epigenetic mechanisms that substantially vary among the B-NHL subtypes.
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    Deregulation of the telomerase reverse transcriptase (TERT) gene by chromosomal translocations in B-cell malignancies
    (American Society of Hematology, 2010) Gascoyne, R.D (R. D.); Tönnies, H. (Holger); Ammerpohl, O. (Ole); Dyer, M.J.S. (Martin J. S.); Martinez-Climent, J.A. (José Ángel); Nagel, I. (Inga); Akasaka, T. (T.); Horsman, D. (D.); Gesk, S. (Stefan); Harder, L. (Lana); Klapper, W. (Wolfram); Callet-Bauchu, E. (E.); Siebert, R. (Reiner); Szczepanowski, M. (Monika); Stilgenbauer, S. (Stepahn); Majid, A. (Aneela); Martin-Subero, J.I. (Jose Ignacio)
    Sequence variants at the TERT-CLPTM1L locus in chromosome 5p have been recently associated with disposition for various cancers. Here we show that this locus including the gene encoding the telomerase reverse-transcriptase TERT at 5p13.33 is rarely but recurrently targeted by somatic chromosomal translocations to IGH and non-IG loci in B-cell neoplasms, including acute lymphoblastic leukemia, chronic lymphocytic leukemia, mantle cell lymphoma and splenic marginal zone lymphoma. In addition, cases with genomic amplification of TERT locus were identified. Tumors bearing chromosomal aberrations involving TERT showed higher TERT transcriptional expression and increased telomerase activity. These data suggest that deregulation of TERT gene by chromosomal abnormalities leading to increased telomerase activity might contribute to B-cell lymphomagenesis.
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    Preneoplastic somatic mutations including MYD88(L265P) in lymphoplasmacytic lymphoma
    (2022) Reinhardt, H.C. (Hans Christian); Vilas, A. (Amaia); Sanchez-Garcia, I. (Isidro); Perez, C. (Cristina); Paiva, A. (Artur); López-de-Arancibia, A. (Aitziber); Sacco, A. (Antonio); Santos, S. (S.); Celay, J. (Jon); Sarvide, S. (Sarai); García-Sanz, R. (Ramón); Goicoechea, I. (Ibai); García-Barchino, M.J. (María José); Martinez-Climent, J.A. (José Ángel); Gárate-Luzuriaga, S. (Sonia); Carrasco, Y.R. (Yolanda R.); Panizo, C. (Carlos); Larrayoz, M. (Marta); Vitoria, H. (Helena); Puig, N. (Noemí); Botta, C. (Cirino); Rodríguez-Díaz, S. (Saray); Garcés-Latre, J.J. (Juan José); Motta, M. (Marina); Geraldes, C. (Catarina); Lamo-de-Espinosa-Vázquez-de-Sola, J.M. (José María); Alignani, D. (Diego); Duarte, S. (Sara); Paiva, B. (Bruno); Larrayoz, M.J. (María J.); Prosper-Cardoso, F. (Felipe); Calasanz-Abinzano, M.J. (Maria Jose); Roccaro, A.M. (Aldo M.); Fuerte, G. (Gema); Tucci, A. (Alessandra); San-Miguel, J.F. (Jesús F.); Gentile, M. (Massimo); Jiménez, C. (Cristina)
    Normal cell counterparts of solid and myeloid tumors accumulate mutations years before disease onset; whether this occurs in B lymphocytes before lymphoma remains uncertain. We sequenced multiple stages of the B lineage in elderly individuals and patients with lymphoplasmacytic lymphoma, a singular disease for studying lymphomagenesis because of the high prevalence of mutated MYD88. We observed similar accumulation of random mutations in B lineages from both cohorts and unexpectedly found MYD88(L265P) in normal precursor and mature B lymphocytes from patients with lymphoma. We uncovered genetic and transcriptional pathways driving malignant transformation and leveraged these to model lymphoplasmacytic lymphoma in mice, based on mutated MYD88 in B cell precursors and BCL2 overexpression. Thus, MYD88(L265P) is a preneoplastic event, which challenges the current understanding of lymphomagenesis and may have implications for early detection of B cell lymphomas.
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    Abnormalities on 1q and 7q are associated with poor outcome in sporadic Burkitt's lymphoma. A cytogenetic and comparative genomic hybridization study
    (Nature Publishing Group, 2003) Gonzalez, D. (D.); Hernandez, J.M. (J. M.); Gonzalez, M.B. (M. B.); Flores, T. (Teresa); Martinez-Climent, J.A. (José Ángel); Gutierrez, N.C. (Norma C.); García, J.L. (J. L.); Lopez-Capitan, C. (C.); Calasanz-Abinzano, M.J. (Maria Jose); Piris, M.A. (Miguel A.); Odero, M.D. (Maria Dolores); San-Miguel, J.F. (Jesús F.)
    Comparative genomic hybridization (CGH) studies have demonstrated a high incidence of chromosomal imbalances in non-Hodgkin's lymphoma. However, the information on the genomic imbalances in Burkitt's Lymphoma (BL) is scanty. Conventional cytogenetics was performed in 34 cases, and long-distance PCR for t(8;14) was performed in 18 cases. A total of 170 changes were present with a median of four changes per case (range 1-22). Gains of chromosomal material (143) were more frequent than amplifications (5) or losses (22). The most frequent aberrations were gains on chromosomes 12q (26%), Xq (22%), 22q (20%), 20q (17%) and 9q (15%). Losses predominantly involved chromosomes 13q (17%) and 4q (9%). High-level amplifications were present in the regions 1q23-31 (three cases), 6p12-p25 and 8p22-p23. Upon comparing BL vs Burkitt's cell leukemia (BCL), the latter had more changes (mean 4.3 +/- 2.2) than BL (mean 2.7 +/- 3.2). In addition, BCL cases showed more frequently gains on 8q, 9q, 14q, 20q, and 20q, 9q, 8q and 14q, as well as losses on 13q and 4q. Concerning outcome, the presence of abnormalities on 1q (ascertained either by cytogenetics or by CGH), and imbalances on 7q (P=0.01) were associated with a short survival.
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    LMO2 expression reflects the different stages of blast maturation and genetic features in B-cell acute lymphoblastic leukemia and predicts clinical outcome
    (Ferrata Storti Foundation, 2011) Fresquet, V. (Vicente); Bobadilla, M. (Míriam); Roman-Gomez, J. (José); Lossos, I.S. (Izidore S.); Martinez-Climent, J.A. (José Ángel); Aznar, M.A. (María Ángela); Martin-Palanco, V. (Vanesa); Raquel; Prosper-Cardoso, F. (Felipe); Robles, E.F. (Eloy Francisco); Calasanz-Abinzano, M.J. (Maria Jose); Altobelli, G.G. (Giovanna G.); Aguirre-Ena, X. (Xabier); Smeland, E.B. (Erlend B.)
    BACKGROUND: LMO2 is highly expressed at the most immature stages of lymphopoiesis. In T-lymphocytes, aberrant LMO2 expression beyond those stages leads to T-cell acute lymphoblastic leukemia, while in B cells LMO2 is also expressed in germinal center lymphocytes and diffuse large B-cell lymphomas, where it predicts better clinical outcome. The implication of LMO2 in B-cell acute lymphoblastic leukemia must still be explored. DESIGN AND METHODS: We measured LMO2 expression by real time RT-PCR in 247 acute lymphoblastic leukemia patient samples with cytogenetic data (144 of them also with survival and immunophenotypical data) and in normal hematopoietic and lymphoid cells. RESULTS: B-cell acute lymphoblastic leukemia cases expressed variable levels of LMO2 depending on immunophenotypical and cytogenetic features. Thus, the most immature subtype, pro-B cells, displayed three-fold higher LMO2 expression than pre-B cells, common-CD10+ or mature subtypes. Additionally, cases with TEL-AML1 or MLL rearrangements exhibited two-fold higher LMO2 expression compared to cases with BCR-ABL rearrangements or hyperdyploid karyotype. Clinically, high LMO2 expression correlated with better overall survival in adult patients (5-year survival rate 64.8% (42.5%-87.1%) vs. 25.8% (10.9%-40.7%), P= 0.001) and constituted a favorable independent prognostic factor in B-ALL with normal karyotype: 5-year survival rate 80.3% (66.4%-94.2%) vs. 63.0% (46.1%-79.9%) (P= 0.043). CONCLUSIONS: Our data indicate that LMO2 expression depends on the molecular features and the differentiation stage of B-cell acute lymphoblastic leukemia cells. Furthermore, assessment of LMO2 expression in adult patients with a normal karyotype, a group which lacks molecular prognostic factors, could be of clinical relevance.
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    Involvement of miRNAs in the differentiation of human glioblastoma multiforme stem-like cells
    (Public Library of Science, 2013) Grande, L. (Lara); Huse, J.T. (Jason T.); Alonso-Roldán, M.M. (Marta María); Nogueira, L. (Lorena); Martinez-Climent, J.A. (José Ángel); Tejada-Solis, S. (Sonia); Aznar, M.A. (María Ángela); Aldaz-Arrieta, B. (Beatriz); Diez-Valle, R. (Ricardo); Fernandez-Luna, J.L. (J.L.); Raquel; Sagardoy, A. (Ainara); Guruceaga, E. (Elizabeth)
    Glioblastoma multiforme (GBM)-initiating cells (GICs) represent a tumor subpopulation with neural stem cell-like properties that is responsible for the development, progression and therapeutic resistance of human GBM. We have recently shown that blockade of NFκB pathway promotes terminal differentiation and senescence of GICs both in vitro and in vivo, indicating that induction of differentiation may be a potential therapeutic strategy for GBM. MicroRNAs have been implicated in the pathogenesis of GBM, but a high-throughput analysis of their role in GIC differentiation has not been reported. We have established human GIC cell lines that can be efficiently differentiated into cells expressing astrocytic and neuronal lineage markers. Using this in vitro system, a microarray-based high-throughput analysis to determine global expression changes of microRNAs during differentiation of GICs was performed. A number of changes in the levels of microRNAs were detected in differentiating GICs, including over-expression of hsa-miR-21, hsa-miR-29a, hsa-miR-29b, hsa-miR-221 and hsa-miR-222, and down-regulation of hsa-miR-93 and hsa-miR-106a. Functional studies showed that miR-21 over-expression in GICs induced comparable cell differentiation features and targeted SPRY1 mRNA, which encodes for a negative regulator of neural stem-cell differentiation. In addition, miR-221 and miR-222 inhibition in differentiated cells restored the expression of stem cell markers while reducing differentiation markers. Finally, miR-29a and miR-29b targeted MCL1 mRNA in GICs and increased apoptosis. Our study uncovers the microRNA dynamic expression changes occurring during differentiation of GICs, and identifies miR-21 and miR-221/222 as key regulators of this process.
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    GeneChip analyses point to novel pathogenetic mechanisms in mantle cell lymphoma
    (Wiley-Blackwell, 2009) Krause, K. (Kristina); Dreyling, M. (Martin); Hasenclever, D. (D.); Kreuz, M. (Markus); Dyer, M.J.S. (Martin J. S.); Berger, H. (H.); Arnold, N. (Norbert); Martinez-Climent, J.A. (José Ángel); Wagner, F. (Florian); Gesk, S. (Stefan); Harder, L. (Lana); Klapper, W. (Wolfram); Zamo, A. (Alberto); Siebert, R. (Reiner); Vater, I. (Inga); Potter, K. (Kathleen N.); Martin-Subero, J.I. (Jose Ignacio)
    The translocation t(11;14)(q13;q32) is the genetic hallmark of mantle cell lymphoma (MCL) but is not sufficient for inducing lymphomagenesis. Here we performed genome-wide 100K GeneChip Mapping in 26 t(11;14)-positive MCL and six MCL cell lines. Partial uniparental disomy (pUPD) was shown to be a recurrent chromosomal event not only in MCL cell lines but also in primary MCL. Remarkably, pUPD affected recurrent targets of deletion like 11q, 13q and 17p. Moreover, we identified 12 novel regions of recurrent gain and loss as well as 12 high-level amplifications and eight homozygously deleted regions hitherto undescribed in MCL. Interestingly, GeneChip analyses identified different genes, encoding proteins involved in microtubule dynamics, such as MAP2, MAP6 and TP53, as targets for chromosomal aberration in MCL. Further investigation, including mutation analyses, fluorescence in situ hybridisation as well as epigenetic and expression studies, revealed additional aberrations frequently affecting these genes. In total, 19 of 20 MCL cases, which were subjected to genetic and epigenetic analyses, and five of six MCL cell lines harboured at least one aberration in MAP2, MAP6 or TP53. These findings provide evidence that alterations of microtubule dynamics might be one of the critical events in MCL lymphomagenesis contributing to chromosomal instability.
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    Lymphoma stem cells: enough evidence to support their existence?
    (Pensiero Scientifico / Ferrata Storti Foundation, 2010) Gascoyne, R.D (R. D.); Martinez-Climent, J.A. (José Ángel); Siebert, R. (Reiner); Fontan, L. (Lorena); Prosper-Cardoso, F. (Felipe)
    While leukemia-originating stem cells are critical in the initiation and maintenance of leukemias, the existence of similar cell populations that may generate B-cell lymphoma upon mutation remains uncertain. Here we propose that committed lymphoid progenitor/precursor cells with an active V-D-J recombination program are the initiating cells of follicular lymphoma and mantle cell lymphoma when targeted by immunoglobulin (IG)- gene translocations in the bone marrow. However, these pre-malignant lymphoma-initiating cells cannot drive complete malignant transformation, requiring additional cooperating mutations in specific stem-cell programs to be converted into the lymphoma-originating cells able to generate and sustain lymphoma development. Conversely, diffuse large B-cell lymphoma and sporadic Burkitt’s lymphoma derive from B lymphocytes that acquire translocations through IG-hyper-mutation or class-switching errors within the germinal center. Although secondary reprogramming mutations are generally required, some cells such as centroblasts or memory B cells that have certain stem cell-like features, or lymphocytes with MYC rearrangements that deregulate self-renewal pathways, may bypass this need and directly function as the lymphoma-originating cells. An alternative model supports an aberrant epigenetic modification of gene sets as the first occurring hit, which either leads to retaining stem-cell features in hematopoietic stem or progenitor cells, or reprograms stemness into more committed lymphocytes, followed by secondary chromosomal translocations that eventually drive lymphoma development. Isolation and characterization of the cells that are at the origin of the different B-cell non-Hodgkin’s lymphomas will provide critical insights into the disease pathogenesis and will represent a step towards the development of more effective therapies.