Nuestros investigadores

Publicaciones científicas más recientes (desde 2010)

Autores: Baliakas, P.; Jeromin, S.; Iskas, M.; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 133  Nº 11  2019  págs. 1205 - 1216
Recent evidence suggests that complex karyotype (CK) defined by the presence of >= 3 chromosomal aberrations (structural and/or numerical) identified by using chromosome-banding analysis (CBA) may be relevant for treatment decision-making in chronic lymphocytic leukemia (CLL). However, many challenges toward the routine clinical application of CBA remain. In a retrospective study of 5290 patients with available CBA data, we explored both clinicobiological associations and the clinical impact of CK in CLL. We found that patients with >= 5 abnormalities, defined as high-CK, exhibit uniformly dismal clinical outcomes, independently of clinical stage, TP53 aberrations (deletion of chromosome 17p and/or TP53 mutations [TP53abs]), and the expression of somatically hypermutated (M-CLL) or unmutated immunoglobulin heavy variable genes. Thus, they contrasted with CK cases with 3 or 4 aberrations (low-CK and intermediate-CK, respectively) who followed aggressive disease courses only in the presence of TP53abs. At the other end of the spectrum, patients with CK and 112,119 displayed an exceptionally indolent profile. Building upon CK, TP53abs, and immunoglobulin heavy variable gene somatic hyper-mutation status, we propose a novel hierarchical model in which patients with high-CK exhibit the worst prognosis, whereas those with mutated CLL lacking CK or TP53abs, as well as CK with 112,119, show the longest overall survival. Thus, CK should not be axiomatically considered unfavorable in CLL, representing a heterogeneous group with variable clinical behavior. High-CK with >= 5 chromosomal aberrations emerges as prognostically adverse, independent of other biomarkers. Prospective clinical validation is warranted before ultimately incorporating high-CK in risk stratification of CLL.
Autores: Martínez, Nicolás; Pascual, M.; et al.
Revista: HAEMATOLOGICA
ISSN 0390-6078  Vol. 104  Nº 8  2019  págs. 1572 - 1579
In this study we interrogated the DNA methylome of myelofibrosis patients using high-density DNA methylation arrays. We detected 35,215 differentially methylated CpG, corresponding to 10,253 genes, between myelofibrosis patients and healthy controls. These changes were present both in primary and secondary myelofibrosis, which showed no differences between them. Remarkably, most differentially methylated CpG were located outside gene promoter regions and showed significant association with enhancer regions. This aberrant enhancer hypermethylation was negatively correlated with the expression of 27 genes in the myelofibrosis cohort. Of these, we focused on the ZFP36L1 gene and validated its decreased expression and enhancer DNA hypermethylation in an independent cohort of patients and myeloid cell-lines. In vitro reporter assay and 5'-azacitidine treatment confirmed the functional relevance of hypermethylation of ZFP36L1 enhancer. Furthermore, in vitro rescue of ZFP36L1 expression had an impact on cell proliferation and induced apoptosis in SET-2 cell line indicating a possible role of ZFP36L1 as a tumor suppressor gene in myelofibrosis. Collectively, we describe the DNA methylation profile of myelofibrosis, identifying extensive changes in enhancer elements and revealing ZFP36L1 as a novel candidate tumor suppressor gene.
Autores: Sargas, C.; Ayala, R. ; Chillon, C. ; et al.
Revista: ANNALS OF HEMATOLOGY
ISSN 0939-5555  Vol. 98  Nº Suppl. 1  2019  págs. S38 - S39
Autores: García, María José; Sarasquete, M. E.; Panizo, Carlos Manuel; et al.
Revista: JOURNAL OF PATHOLOGY
ISSN 0022-3417  Vol. 245  Nº 1  2018  págs. 61 - 73
The increased risk of Richter transformation (RT) in patients with chronic lymphocytic leukaemia (CLL) due to Epstein-Barr virus (EBV) reactivation during immunosuppressive therapy with fludarabine other targeted agents remains controversial. Among 31 RT cases classified as diffuse large B-cell lymphoma (DLBCL), seven (23%) showed EBV expression. In contrast to EBV- tumours, EBV+ DLBCLs derived predominantly from IGVH-hypermutated CLL, and they also showed CLL-unrelated IGVH sequences more frequently. Intriguingly, despite having different cellular origins, clonally related and unrelated EBV+ DLBCLs shared a previous history of immunosuppressive chemo-immunotherapy, a non-germinal centre DLBCL phenotype, EBV latency programme type II or III, and very short survival. These data suggested that EBV reactivation during therapy-related immunosuppression can transform either CLL cells or non-tumoural B lymphocytes into EBV+ DLBCL. To investigate this hypothesis, xenogeneic transplantation of blood cells from 31 patients with CLL and monoclonal B-cell lymphocytosis (MBL) was performed in Rag2(-/-) IL2c(-/-) mice. Remarkably, the recipients' impaired immunosurveillance favoured the spontaneous outgrowth of EBV+ B-cell clones from 95% of CLL and 64% of MBL patients samples, but not from healthy donors. Eventually, these cells generated monoclonal tumours (mostly CLL-unrelated but also CLL-related), recapitulating the principal features of EBV+ DLBCL in patients. Accordingly, clonally related and unrelated EBV+ DLBCL xenografts showed indistinguishable cellular, virological and molecular features, and synergistically responded to combined inhibition of EBV replication with ganciclovir and B-cell receptor signalling with ibrutinib in vivo. Our study underscores the risk of RT driven by EBV in CLL patients receiving immunosuppressive therapies, and provides the scientific rationale for testing ganciclovir and ibrutinib in EBV+ DLBCL. Copyright (c) 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Autores: Ubieto, A. J. ; Lourenco, Bruno David; Martinez-Lopez, J.; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 132  Nº Suppl 1  2018  págs. 474
Background: The international criteria for definition CR, requires, among other parametres, a negative IF both in serum and urine; however, urine IF is not always performed. In the belief that this lack could bias the comparison between trials, the First Trial Independent Response Adjudication Committee (FTIRAC) recommended that patients who met all CR criteria except the availability of a urine IF should be classified as VGPR (Blood 2014; 124 [abstract 3460]) but this criteria is not always applied which may translate into differences in CR rates between trials. However, it is unknown (1) if this conversion has a real clinical basis, (2) if urine IF results alter the clinical meaning of CR, or (3) on the contrary, if patients in CR with and those without a documented negative urine IF have a similar prognosis, in which case this rule would underestimate the CR rates, increasing the biases and magnifying the problem that was intended to improve. Aim: To determine the value of urine negative IF in the definition of CR.
Autores: Espinet, B. ; Ramos, S.; Gomez-Llonin, A.; et al.
Revista: MODERN PATHOLOGY
ISSN 0893-3952  Vol. 31  Nº Supl. 2  2018  págs. 514 - 514
Autores: Jiménez-Ubieto, A.; Martinez-Lopez, J.; Rosinol, L. ; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 132  Nº Suppl 1  2018  págs. 1943
Introduction: To discriminate different outcomes among patients in CR, the International Myeloma Working Group (IMWG )introduced more stringent CR (sCR) criteria by adding to the pre-existing CR parameters the requirement of a normal free-light chain ratio (sFLCr) plus the absence of clonal plasma cells (PCs) in bone marrow (BM) by immunohistochemistry (IHC). In 2011,the low-sensitivity cytometrycriteria were included as alternative methodology to IHC to define sCR. Aim: To validate the preliminary data of our previous study (Blood 2015. 126:858-62) regarding the lack of influence of an abnormal sFLCr in the outcome of MM patients, through the analysis of a more extensiveseries of newly diagnosed multiple myeloma (NDMM) patients in CR or sCR. Patients and Methods: This study is based on 459 NDMM patients who were transplant candidates and enrolled in the GEM2012MENOS65phase 3trial;evaluable patients were enrolled in a subsequent maintenance trial (NCT02406144).CR and sCR was defined according to the IMWG criteria.
Autores: Goicoechea, Ibai; Puig, N. ; Cedena, M. T. ; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 132  Nº Supl. 1  2018  págs. 112
Autores: Puiggros, A.; Collado, R.; Calasanz, María José; et al.
Revista: ONCOTARGET
ISSN 1949-2553  Vol. 8  Nº 33  2017  págs. 54297 - 54303
Genomic complexity identified by chromosome banding analysis (CBA) predicts a worse clinical outcome in CLL patients treated either with standard or new treatments. Herein, we analyzed the clinical impact of complex karyotypes (CK) with or without high-risk FISH deletions (ATM and/or TP53, HR-FISH) in a cohort of 1045 untreated MBL/CLL patients. In all, 99/1045 (9.5%) patients displayed a CK. Despite ATM and TP53 deletions were more common in CK (25% vs 7%; P < 0.001; 40% vs 5%; P < 0.001, respectively), only 44% (40/90) patients with TP53 deletions showed a CK. CK group showed a significant higher two-year cumulative incidence of treatment (48% vs 20%; P < 0.001), as well as a shorter overall survival (OS) (79 mo vs not reached; P < 0.001). When patients were categorized regarding CK and HR-FISH, those with both characteristics showed the worst median OS (52 mo) being clearly distinct from those non-CK and non-HR-FISH (median not reached), but no significant differences were detected between cases with only CK or HR-FISH. Both CK and TP53 deletion remained statistically significant in the multivariate analysis for OS. In conclusion, CK group is globally associated with advanced disease and poor prognostic markers. Further investigation in larger cohorts with CK lacking HR-FISH is needed to elucidate which mechanisms underlie the poor outcome of this subgroup.
Autores: Collado, R.; Puiggros, A.; López-Guerrero, J. A.; et al.
Revista: CANCER LETTERS
ISSN 0304-3835  Vol. 409  2017  págs. 42 - 48
Although i(17q) [i(17q)] is frequently detected in hematological malignancies, few studies have assessed its clinical role in chronic lymphocytic leukemia (CLL). We recruited a cohort of 22 CLL patients with i(17q) and described their biological characteristics, mutational status of the genes TP53 and IGHV and genomic complexity. Furthermore, we analyzed the impact of the type of cytogenetic anomaly bearing the TP53 defect on the outcome of CLL patients and compared the progression-free survival (PFS) and overall survival (OS) of i(17q) cases with those of a group of 38 CLL patients harboring other 17p aberrations. We detected IGHV somatic hypermutation in all assessed patients, and TP53 mutations were observed in 71.4% of the cases. Patients with i(17q) were more commonly associated with complex karyotypes (CK) and tended to have a poorer OS than patients with other anomalies affecting 17p13 (median OS, 44 vs 120 months, P = 0.084). Regarding chromosomal alterations, significant differences in the median OS were found among groups (P = 0.044). In conclusion, our findings provide new insights regarding i(17q) in CLL and show a subgroup with adverse prognostic features.
Autores: Rio-Machin, A.; Gomez-Lopez, G.; Munoz, J. ; et al.
Revista: LEUKEMIA
ISSN 0887-6924  Vol. 31  Nº 9  2017  págs. 2000 - 2005
Autores: Baptista, M. J.; Granada, I.; Morgades, M.; et al.
Revista: AMERICAN JOURNAL OF HEMATOLOGY
ISSN 0361-8609  Vol. 92  Nº 7  2017  págs. E132 - E135
Autores: Martínez, Nicolás; Pascual, M.; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 130  Nº Supl. 1  2017 
Autores: Garcia-Ramirez, P.; Vicente, Carmen; Arriazu, Elena; et al.
Revista: HAEMATOLOGICA
ISSN 0390-6078  Vol. 102  2017  págs. 50 - 50
Autores: Puiggros, A.; Gomez-Llonin, A.; Ramos, S.; et al.
Revista: HAEMATOLOGICA
ISSN 0390-6078  Vol. 102  Nº Supl. 2  2017  págs. 422 - 422
Autores: Fernandez-Rodriguez, C.; Ayala, R.; Barragan, E.; et al.
Revista: HAEMATOLOGICA
ISSN 0390-6078  Vol. 102  Nº Supl. 2  2017  págs. 278 - 278
Autores: Baliakas, P.; Jeromin, S.; Iskas, M.; et al.
Revista: HAEMATOLOGICA
ISSN 0390-6078  Vol. 102  Nº Supl. 2  2017  págs. 170 - 170
Autores: Fernández, Marta; Larráyoz, María José; Vázquez, Iria; et al.
Revista: HAEMATOLOGICA
ISSN 0390-6078  Vol. 102  Nº Supl. 2  2017  págs. 46 - 46
Autores: Nomdedeu, M.; Calvo, X.; Pereira, A.; et al.
Revista: GENES CHROMOSOMES AND CANCER
ISSN 1045-2257  Vol. 55  Nº 4  2016  págs. 322 - 327
Chromosomal translocations are rare in the myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML). With the exception of t(3q), translocations are not explicitly considered in the cytogenetic classification of the IPSS-R and their impact on disease progression and patient survival is unknown. The present study was aimed at determining the prognostic impact of translocations in the context of the cytogenetic classification of the IPSS-R. We evaluated 1,653 patients from the Spanish Registry of MDS diagnosed with MDS or CMML and an abnormal karyotype by conventional cytogenetic analysis. Translocations were identified in 168 patients (T group). Compared with the 1,485 patients with abnormal karyotype without translocations (non-T group), the T group had a larger proportion of patients with refractory anemia with excess of blasts and higher scores in both the cytogenetic and global IPSS-R. Translocations were associated with a significantly shorter survival and higher incidence of transformation into AML at univariate analysis but both features disapeared after multivariate adjustment for the IPSS-R cytogenetic category. Patients with single or double translocations other than t(3q) had an outcome similar to those in the non-T group in the intermediate cytogenetic risk category of the IPSS-R. In conclusion, the presence of translocations identifies a subgroup of MDS/CMML patients with a more aggressive clinical presentation that can be explained by a higher incidence of complex karyotypes. Single or double translocations other than t(3q) should be explicitly considered into the intermediate risk category of cytogenetic IPSS-R classification.
Autores: Robles, Eloy Francisco; Barrio, L.; Merino-Cortés, S. V.; et al.
Revista: NATURE COMMUNICATIONS
ISSN 2041-1723  Vol. 7  2016  págs. 11889
NKX2 homeobox family proteins have a role in cancer development. Here we show that NKX2-3 is overexpressed in tumour cells from a subset of patients with marginal-zone lymphomas, but not with other B-cell malignancies. While Nkx2-3-deficient mice exhibit the absence of marginal-zone B cells, transgenic mice with expression of NKX2-3 in B cells show marginal-zone expansion that leads to the development of tumours, faithfully recapitulating the principal clinical and biological features of human marginal-zone lymphomas. NKX2-3 induces B-cell receptor signalling by phosphorylating Lyn/Syk kinases, which in turn activate multiple integrins (LFA-1, VLA-4), adhesion molecules (ICAM-1, MadCAM-1) and the chemokine receptor CXCR4. These molecules enhance migration, polarization and homing of B cells to splenic and extranodal tissues, eventually driving malignant transformation through triggering NF-¿B and PI3K-AKT pathways. This study implicates oncogenic NKX2-3 in lymphomagenesis, and provides a valid experimental mouse model for studying the biology and therapy of human marginal-zone B-cell lymphomas
Autores: Queirós, A. C.; Beekman, R.; Vilarrasa-Blasi, R.; et al.
Revista: CANCER CELL
ISSN 1535-6108  Vol. 30  Nº 5  2016  págs. 806 - 821
We analyzed the in silico purified DNA methylation signatures of 82 mantle cell lymphomas (MCL) in comparison with cell subpopulations spanning the entire B cell lineage. We identified two MCL subgroups, respectively carrying epigenetic imprints of germinal-center-inexperienced and germinal-center-experienced B cells, and we found that DNA methylation profiles during lymphomagenesis are largely influenced by the methylation dynamics in normal B cells. An integrative epigenomic approach revealed 10,504 differentially methylated regions in regulatory elements marked by H3K27ac in MCL primary cases, including a distant enhancer showing de novo looping to the MCL oncogene SOX11. Finally, we observed that the magnitude of DNA methylation changes per case is highly variable and serves as an independent prognostic factor for MCL outcome.
Autores: Blanco, G.; Puiggros, A.; Baliakas, P.; et al.
Revista: ONCOTARGET
ISSN 1949-2553  Vol. 7  Nº 49  2016  págs. 80916 - 80924
Patients with chronic lymphocytic leukemia (CLL) harboring TP53 aberrations (TP53abs; chromosome 17p deletion and/or TP53 mutation) exhibit an unfavorable clinical outcome. Chromosome 8 abnormalities, namely losses of 8p (8p-) and gains of 8q (8q+) have been suggested to aggravate the outcome of patients with TP53abs. However, the reported series were small, thus hindering definitive conclusions. To gain insight into this issue, we assessed a series of 101 CLL patients harboring TP53 disruption. The frequency of 8p- and 8q+ was 14.7% and 17.8% respectively. Both were associated with a significantly (P < 0.05) higher incidence of a complex karyotype (CK, >= 3 abnormalities) detected by chromosome banding analysis (CBA) compared to cases with normal 8p (N-8p) and 8q (N-8q), respectively. In univariate analysis for 10- year overall survival (OS), 8p- (P = 0.002), 8q+ (P = 0.012) and CK (P = 0.009) were associated with shorter OS. However, in multivariate analysis only CK (HR = 2.47, P = 0.027) maintained independent significance, being associated with a dismal outcome regardless of chromosome 8 abnormalities. In conclusion, our results highlight the association of chromosome 8 abnormalities with CK amongst CLL patients with TP53abs, while also revealing that CK can further aggravate the prognosis of this aggressive subgroup.
Autores: Pellagatti, A.; Roy, S.; Di Genua, C.; et al.
Revista: LEUKEMIA
ISSN 0887-6924  Vol. 30  Nº 1  2016  págs. 247 - 250
Autores: Palomo, L.; Xicoy, B.; García, O.; et al.
Revista: AMERICAN JOURNAL OF HEMATOLOGY
ISSN 0361-8609  Vol. 91  Nº 2  2016  págs. 185 - 192
Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic disorder with heterogeneous clinical, morphological and genetic characteristics. Clonal cytogenetic abnormalities are found in 20-30% of patients with CMML. Patients with low risk cytogenetic features (normal karyotype and isolated loss of Y chromosome) account for ~80% of CMML patients and often fall into the low risk categories of CMML prognostic scores. We hypothesized that single nucleotide polymorphism arrays (SNP-A) karyotyping could detect cryptic chromosomal alterations with prognostic impact in these subgroup of patients. SNP-A were performed at diagnosis in 128 CMML patients with low risk karyotypes or uninformative results for conventional G-banding cytogenetics (CC). Copy number alterations (CNAs) and regions of copy number neutral loss of heterozygosity (CNN-LOH) were detected in 67% of patients. Recurrent CNAs included gains in regions 8p12 and 21q22 as well as losses in 10q21.1 and 12p13.2. Interstitial CNN-LOHs were recurrently detected in the following regions: 4q24-4q35, 7q32.1-7q36.3, and 11q13.3-11q25. Statistical analysis showed that some of the alterations detected by SNP-A associated with the patients' outcome. A shortened overall survival (OS) and progression free survival (PFS) was observed in cases where the affected size of the genome (considering CNAs and CNN-LOHs) was >11 Mb. In addition, presence of interstitial CNN-LOH was predictive of poor OS. Presence of CNAs (¿1) associated with poorer OS and PFS in the patients with myeloproliferative CMML. Overall, SNP-A analysis increased the diagnostic yield in patients with low risk cytogenetic features or uninformative CC and added prognostic value to this subset of patients.
Autores: Costa, D.; Muñoz, C.; Carrió, A.; et al.
Revista: ACTA HAEMATOLOGICA
ISSN 0001-5792  Vol. 135  Nº 2  2016  págs. 94 - 100
Recurrent translocations are uncommon in myelodysplastic syndromes (MDS). Three new recurrent translocations, namely der(12)t(3;12)(q13;p13), t(11; 13;22)(q 13;q14;q 12) and der(17)t(13;17)(q21;p13), identified by conventional cytogenetics (CC) in 4 MDS patients, were further characterized using a panel of commercial and homemade fluorescence in situ hybridization (FISH) probes. The goal of this study was to determine the precise breakpoints and to identify genes that could be related with the neoplastic process. Half of the breakpoints (4/8) were precisely identified and in the remaining half they were narrowed to a region ranging from 14 to 926 kb. All the studied breakpoints had interstitial or terminal deletions ranging from 536 kb to 89 Mb, and only those >= 7 Mb were detected by CC. The genes located in or around the breakpoints described in our study have not been previously related to MDS. The deleted regions include the ETV6 and RBI genes, among others, and exclude the TP53 gene. FISH studies were useful to refine the breakpoints of the translocations, but further studies are needed to determine the role of the involved genes in the neoplastic process.
Autores: Alignani, D.; Delgado, JA; et al.
Revista: CLINICAL OTOLARYNGOLOGY
ISSN 1749-4478  Vol. 41  Nº 5  2016  págs. 606-611
Autores: Lourenco, Bruno David; Puig, N. ; Cedena, M. T.; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 128  Nº 22  2016 
Autores: Burgos, Leire; Garcés, Juan-José; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 128  Nº 22  2016 
Autores: Blanco, G.; Puiggros, A.; Baliakas, P.; et al.
Revista: HAEMATOLOGICA
ISSN 0390-6078  Vol. 101  Nº Supl. 4  2016  págs. 196 - 197
Autores: Adema, V.; Larráyoz, María José; Calasanz, María José; et al.
Revista: BRITISH JOURNAL OF HAEMATOLOGY
ISSN 0007-1048  Vol. 171  Nº 1  2015  págs. 137 - 141
Autores: Costa, D.; Muñoz, C.; Carrió, A.; et al.
Revista: ACTA HAEMATOLOGICA
ISSN 0001-5792  Vol. 135  Nº 2  2015  págs. 94 - 100
Recurrent translocations are uncommon in myelodysplastic syndromes (MDS). Three new recurrent translocations, namely der(12)t(3;12)(q13;p13), t(11;13;22)(q13;q14;q12) and der(17)t(13;17)(q21;p13), identified by conventional cytogenetics (CC) in 4 MDS patients, were further characterized using a panel of commercial and homemade fluorescence in situ hybridization (FISH) probes. The goal of this study was to determine the precise breakpoints and to identify genes that could be related with the neoplastic process. Half of the breakpoints (4/8) were precisely identified and in the remaining half they were narrowed to a region ranging from 14 to 926 kb. All the studied breakpoints had interstitial or terminal deletions ranging from 536 kb to 89 Mb, and only those 7 Mb were detected by CC. The genes located in or around the breakpoints described in our study have not been previously related to MDS. The deleted regions include the ETV6 and RB1 genes, among others, and exclude the TP53 gene. FISH studies were useful to refine the breakpoints of the translocations, but further studies are needed to determine the role of the involved genes in the neoplastic process.
Autores: Bello, E.; Pellagatti, A.; Shaw, J.; et al.
Revista: BRITISH JOURNAL OF HAEMATOLOGY
ISSN 0007-1048  Vol. 171  Nº 2  2015  págs. 210 - 214
Mutations of CSNK1A1, a gene mapping to the commonly deleted region of the 5q-syndrome, have been recently described in patients with del(5q) myelodysplastic syndromes (MDS). Haploinsufficiency of Csnk1a1 in mice has been shown to result in beta-catenin activation and expansion of haematopoietic stem cells (HSC). We have screened a large cohort of 104 del(5q) MDS patients and have identified mutations of CSNK1A1 in five cases (approximately 5%). We have shown up-regulation of beta-catenin target genes in the HSC of patients with del(5q) MDS. Our data further support a central role of CSNK1A1 in the pathogenesis of MDS with del(5q).
Autores: Agirre, X; Castellano, G.; Pascual, M.; et al.
Revista: GENOME RESEARCH
ISSN 1088-9051  Vol. 25  Nº 4  2015  págs. 478 - 487
While analyzing the DNA methylome of multiple myeloma (MM), a plasma cell neoplasm, by whole-genome bisulfite sequencing and high-density arrays, we observed a highly heterogeneous pattern globally characterized by regional DNA hypermethylation embedded in extensive hypomethylation. In contrast to the widely reported DNA hypermethylation of promoter-associated CpG islands (CGIs) in cancer, hypermethylated sites in MM, as opposed to normal plasma cells, were located outside CpG islands and were unexpectedly associated with intronic enhancer regions defined in normal B cells and plasma cells. Both RNA-seq and in vitro reporter assays indicated that enhancer hypermethylation is globally associated with down-regulation of its host genes. ChIP-seq and DNase-seq further revealed that DNA hypermethylation in these regions is related to enhancer decommissioning. Hypermethylated enhancer regions overlapped with binding sites of B cell-specific transcription factors (TFs) and the degree of enhancer methylation inversely correlated with expression levels of these TFs in MM. Furthermore, hypermethylated regions in MM were methylated in stem cells and gradually became demethylated during normal B-cell differentiation, suggesting that MM cells either reacquire epigenetic features of undifferentiated cells or maintain an epigenetic signature of a putative myeloma stem cell progenitor. Overall, we have identified DNA hypermethylation of developmentally regulated enhancers as a new type of epigenetic modification associated with the pathogenesis of MM.
Autores: McGraw, K. L.; Zhang, L. M.; Rollison, D. E.; et al.
Revista: BLOOD CANCER JOURNAL
ISSN 2044-5385  Vol. 5  2015  págs. e291
Nonsynonymous TP53 exon 4 single-nucleotide polymorphism (SNP), R72P, is linked to cancer and mutagen susceptibility. R72P associations with specific cancer risk, particularly hematological malignancies, have been conflicting. Myelodysplastic syndrome (MDS) with chromosome 5q deletion is characterized by erythroid hypoplasia arising from lineage-specific p53 accumulation resulting from ribosomal insufficiency. We hypothesized that apoptotically diminished R72P C-allele may influence predisposition to del(5q) MDS. Bone marrow and blood DNA was sequenced from 705 MDS cases (333 del(5q), 372 non-del(5q)) and 157 controls. Genotype distribution did not significantly differ between del(5q) cases (12.6% CC, 38.1% CG, 49.2% GG), non-del(5q) cases (9.7% CC, 44.6% CG, 45.7% GG) and controls (7.6% CC, 37.6% CG, 54.8% GG) (P=0.13). Allele frequency did not differ between non-del(5q) and del(5q) cases (P=0.91) but trended towards increased C-allele frequency comparing non-del(5q) (P=0.08) and del(5q) (P=0.10) cases with controls. Median lenalidomide response duration increased proportionate to C-allele dosage in del(5q) patients (2.2 (CC), 1.3 (CG) and 0.89 years (GG)). Furthermore, C-allele homozygosity in del(5q) was associated with prolonged overall and progression-free survival and non-terminal interstitial deletions that excluded 5q34, whereas G-allele homozygozity was associated with inferior outcome and terminal deletions involving 5q34 (P=0.05). These findings comprise the largest MDS R72P SNP analysis.
Autores: Barragán, E.; Chillón, M. C.; Marcotegui, Nerea; et al.
Revista: HAEMATOLOGICA-THE HEMATOLOGY JOURNAL
ISSN 0390-6078  Vol. 100  Nº 5  2015  págs. e183 - e185
Autores: Agirre, X; Castellano, G.; Heath, S.; et al.
Revista: HAEMATOLOGICA
ISSN 0390-6078  Vol. 100  Nº Supl. 4  2015  págs. 41 - 42
Autores: Puiggros, A.; Venturas, M.; Salido, M.; et al.
Revista: GENES CHROMOSOMES AND CANCER
ISSN 1045-2257  Vol. 53  Nº 9  2014  págs. 788 - 797
Deletion of 13q14 as the sole abnormality is a good prognostic marker in chronic lymphocytic leukemia (CLL). Nonetheless, the prognostic value of reciprocal 13q14 translocations [t(13q)] with related 13q losses has not been fully elucidated. We described clinical and biological characteristics of 25 CLL patients with t(13q), and compared with 62 patients carrying interstitial del(13q) by conventional G-banding cytogenetics (CGC) [i-del(13q)] and 295 patients with del(13q) only detected by fluorescence in situ hybridization (FISH) [F-del(13q)]. Besides from the CLL FISH panel (D13S319, CEP12, ATM, TP53), we studied RB1 deletions in all t(13q) cases and a representative group of i-del(13q) and F-del(13q). We analyzed NOTCH1, SF3B1, and MYD88 mutations in t(13q) cases by Sanger sequencing. In all, 25 distinct t(13q) were described. All these cases showed D13S319 deletion while 32% also lost RB1. The median percentage of 13q-deleted nuclei did not differ from i-del(13q) patients (73% vs. 64%), but both were significantly higher than F-del(13q) (52%, P < 0.001). Moreover, t(13q) patients showed an increased incidence of biallelic del(13q) (52% vs. 11.3% and 14.9%, P < 0.001) and higher rates of concomitant 17p deletion (37.5% vs. 8.6% and 7.2%, P < 0.001). RB1 involvement was significantly higher in the i-del(13q) group (79%, P < 0.001). Two t(13q) patients (11.8%) carried NOTCH1 mutations. Time to first treatment in t(13q) and i-del(13q) was shorter than F-del(13q) (67, 44, and 137 months, P=0.029), and preserved significance in the multivariate analysis. In conclusion, t(13q) and del(13q) patients detected by CGC constitute a subgroup within the 13q-deleted CLL patients associated with a worse clinical outcome.
Autores: Guillaumet-Adkins, A.; Richter, J.; Odero, María Dolores; et al.
Revista: JOURNAL OF HEMATOLOGY AND ONCOLOGY
ISSN 1756-8722  Vol. 7  Nº 4  2014  págs. 1 - 11
Background: Wilms tumor 1 (WT1) is over-expressed in numerous cancers with respect to normal cells, and has either a tumor suppressor or oncogenic role depending on cellular context. This gene is associated with numerous alternatively spliced transcripts, which initiate from two different unique first exons within the WT1 and the alternative (A) WT1 promoter intervals. Within the hematological system, WT1 expression is restricted to CD34+/ CD38- cells and is undetectable after differentiation. Detectable expression of this gene is an excellent marker for minimal residual disease in acute myeloid leukemia (AML), but the underlying epigenetic alterations are unknown. Methods: To determine the changes in the underlying epigenetic landscape responsible for this expression, we characterized expression, DNA methylation and histone modification profiles in 28 hematological cancer cell lines and confirmed the methylation signature in 356 cytogenetically well-characterized primary hematological malignancies. Results: Despite high expression of WT1 and AWT1 transcripts in AML-derived cell lines, we observe robust hypermethylation of the AWT1 promoter and an epigenetic switch from a permissive to repressive chromatin structure between normal cells and AML cell lines. Subsequent methylation analysis in our primary leukemia and lymphoma cohort revealed that the epigenetic signature identified in cell lines is specific to myeloid-lineage malignancies, irrespective of underlying mutational status or translocation. In addition to being a highly specific marker for AML diagnosis (positive predictive value 100%; sensitivity 86.1%; negative predictive value 89.4%), we show that AWT1 hypermethylation also discriminates patients that relapse from those achieving complete remission after hematopoietic stem cell transplantation, with similar efficiency to WT1 expression profiling. Conclusions: We describe a methylation signature of the AWT1 promoter CpG island that is a promising marker for classifying myeloid-derived leukemias. In addition AWT1 hypermethylation is ideally suited to monitor the recurrence of disease during remission in patients undergoing allogeneic stem cell transfer.
Autores: Menezes, J.; Acquadro, F.; Wiseman, M.; et al.
Revista: LEUKEMIA
ISSN 0887-6924  Vol. 28  Nº 4  2014  págs. 823 - 829
Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a very rare disease that currently lacks genomic and genetic biomarkers to assist in its clinical management. We performed whole-exome sequencing (WES) of three BPDCN cases. Based on these data, we designed a resequencing approach to identify mutations in 38 selected genes in 25 BPDCN samples. WES revealed 37-99 deleterious gene mutations per exome with no common affected genes between patients, but with clear overlap in terms of molecular and disease pathways (hematological and dermatological disease). We identified for the first time deleterious mutations in IKZF3, HOXB9, UBE2G2 and ZEB2 in human leukemia. Target sequencing identified 29 recurring genes, ranging in prevalence from 36% for previously known genes, such as TET2, to 12-16% for newly identified genes, such as IKZF3 or ZEB2. Half of the tumors had mutations affecting either the DNA methylation or chromatin remodeling pathways. The clinical analysis revealed that patients with mutations in DNA methylation pathway had a significantly reduced overall survival (P= 0.047). We provide the first mutational profiling of BPDCN. The data support the current WHO classification of the disease as a myeloid disorder and provide a biological rationale for the incorporation of epigenetic therapies for its treatment.
Autores: Saumell, S.; Florensa, L.; Rodríguez-Rivera, M.; et al.
Revista: LEUKEMIA AND LYMPHOMA
ISSN 1042-8194  Vol. 56  Nº 1  2014  págs. 242 - 243
Autores: Pellagatti, A.; Fernández, Marta; Di Genua, C.; et al.
Revista: LEUKEMIA
ISSN 0887-6924  Vol. 28  Nº 5  2014  págs. 1148 - 1151
Autores: Agirre, X; Castellano, G.; Health, S.; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 124  Nº 21  2014 
Autores: Rio-Machin, A.; Ferreira, B. I.; Henry, T.; et al.
Revista: LEUKEMIA
ISSN 0887-6924  Vol. 27  Nº 4  2013  págs. 925 - 931
Currently, multiple myeloma (MM) patients are broadly grouped into a non-hyperdiploid (nh-MM) group, highly enriched for IgH translocations, or into a hyperdiploid (h-MM) group, which is typically characterized by trisomies of some odd-numbered chromosomes. We compared the micro RNA (miRNA) expression profiles of these two groups and we identified 16 miRNAs that were downregulated in the h-MM group, relative to the nh-MM group. We found that target genes of the most differentially expressed miRNAs are directly involved in the pathogenesis of MM; specifically, the inhibition of hsa-miR-425, hsa-miR-152 and hsa-miR-24, which are all downregulated in h-MM, leads to the overexpression of CCND1, TACC3, MAFB, FGFR3 and MYC, which are the also the oncogenes upregulated by the most frequent IgH chromosomal translocations occurring in nh-MM. Importantly, we showed that the downregulation of these specific miRNAs and the upregulation of their targets also occur simultaneously in primary cases of h-MM. These data provide further evidence on the unifying role of cyclin D pathways deregulation as the key mechanism involved in the development of both groups of MM. Finally, they establish the importance of miRNA deregulation in the context of MM, thereby opening up the potential for future therapeutic approaches based on this molecular mechanism.
Autores: Puiggros, A.; Delgado, J.; Rodríguez-Vicente, A.; et al.
Revista: BRITISH JOURNAL OF HAEMATOLOGY
ISSN 0007-1048  Vol. 163  Nº 1  2013  págs. 47 - 54
Losses in 13q as a sole abnormality confer a good prognosis in chronic lymphocytic leukaemia (CLL). Nevertheless, its heterogeneity has been demonstrated and the clinical significance of biallelic 13q deletions remains controversial. We compared the clinico-biological characteristics of a series of 627 patients harbouring isolated 13q deletions by fluorescence in situ hybridization (FISH), either monoallelic (13q × 1), biallelic (13q × 2), or the coexistence of both clones (13qM). The most frequent 13q deletion was 13q × 1 (82·1%), while 13q × 2 and 13qM represented 8·6% and 9·3% of patients respectively. The median percentage of altered nuclei significantly differed across groups: 55%, 72·5% and 80% in 13q × 1, 13q × 2 and 13qM (P < 0·001). However, no significant differences in the clinical outcome among 13q groups were found. From 84 patients with sequential FISH studies, eight patients lost the remaining allele of 13q whereas none of them changed from 13q × 2 to the 13q × 1 group. The percentage of abnormal cells detected by FISH had a significant impact on the five-year cumulative incidence of treatment and the overall survival, 90% being the highest predictive power cut-off. In conclusion, loss of the remaining 13q allele is not enough to entail a worse prognosis in CLL. The presence of isolated 13q deletion can be risk-stratified according to the percentage of altered cells.
Autores: Bea, S.; Valdez-Mas, R.; Navarro, A.; et al.
Revista: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
ISSN 0027-8424  Vol. 110  Nº 45  2013  págs. 18250 - 18255
Mantle cell lymphoma (MCL) is an aggressive tumor, but a subset of patients may follow an indolent clinical course. To understand the mechanisms underlying this biological heterogeneity, we performed whole-genome and/or whole-exome sequencing on 29 MCL cases and their respective matched normal DNA, as well as 6 MCL cell lines. Recurrently mutated genes were investigated by targeted sequencing in an independent cohort of 172 MCL patients. We identified 25 significantly mutated genes, including known drivers such as ataxia-telangectasia mutated (ATM), cyclin D1 (CCND1), and the tumor suppressor TP53; mutated genes encoding the anti-apoptotic protein BIRC3 and Toll-like receptor 2 (TLR2); and the chromatin modifiers WHSC1, MLL2, and MEF2B. We also found NOTCH2 mutations as an alternative phenomenon to NOTCH1 mutations in aggressive tumors with a dismal prognosis. Analysis of two simultaneous or subsequent MCL samples by whole-genome/whole-exome (n = 8) or targeted (n = 19) sequencing revealed subclonal heterogeneity at diagnosis in samples from different topographic sites and modulation of the initial mutational profile at the progression of the disease. Some mutations were predominantly clonal or subclonal, indicating an early or late event in tumor evolution, respectively. Our study identifies molecular mechanisms contributing to MCL pathogenesis and offers potential targets for therapeutic intervention.
Autores: Perez, C.; Martín-Subero, J. I.; Bellosillo, B.; et al.
Revista: HAEMATOLOGICA-THE HEMATOLOGY JOURNAL
ISSN 0390-6078  Vol. 98  Nº 9  2013  págs. 1414 - 1420
Most DNA methylation studies in classic Philadelphia-negative myeloproliferative neoplasms have been performed on a gene-by-gene basis. Therefore, a more comprehensive methylation profiling is needed to study the implications of this epigenetic marker in myeloproliferative neoplasms. Here, we have analyzed 71 chronic (24 polycythemia vera, 23 essential thrombocythemia and 24 primary myelofibrosis) and 13 transformed myeloproliferative neoplasms using genome-wide DNA methylation arrays. The three types of chronic Philadelphia-negative myeloproliferative neoplasms showed a similar aberrant DNA methylation pattern when compared to control samples. Differentially methylated regions were enriched in a gene network centered on the NF-¿B pathway, indicating that they may be involved in the pathogenesis of these diseases. In the case of transformed myeloproliferative neoplasms, we detected an increased number of differentially methylated regions with respect to chronic myeloproliferative neoplasms. Interestingly, these genes were enriched in a list of differentially methylated regions in primary acute myeloid leukemia and in a gene network centered around the IFN pathway. Our results suggest that alterations in the DNA methylation landscape play an important role in the pathogenesis and leukemic transformation of myeloproliferative neoplasms. The therapeutic modulation of epigenetically-deregulated pathways may allow us to design targeted therapies for these patients.
Autores: Mallo, M.; Del Rey, M.; Ibáñez, M.; et al.
Revista: BRITISH JOURNAL OF HAEMATOLOGY
ISSN 0007-1048  Vol. 162  Nº 1  2013  págs. 74 - 86
Lenalidomide is an effective drug in low-risk myelodysplastic syndromes (MDS) with isolated del(5q), although not all patients respond. Studies have suggested a role for TP53 mutations and karyotype complexity in disease progression and outcome. In order to assess the impact of complex karyotypes on treatment response and disease progression in 52 lenalidomide-treated patients with del(5q) MDS, conventional G-banding cytogenetics (CC), single nucleotide polymorphism array (SNP-A), and genomic sequencing methods were used. SNP-A analysis (with control sample, lymphocytes CD3+, in 30 cases) revealed 5q losses in all cases. Other recurrent abnormalities were infrequent and were not associated with lenalidomide responsiveness. Low karyotype complexity (by CC) and a high baseline platelet count (>280x109/l) were associated with the achievement of haematological response (P=0020, P=0013 respectively). Unmutated TP53 status showed a tendency for haematological response (P=0061). Complete cytogenetic response was not observed in any of the mutated TP53 cases. By multivariate analysis, the most important predictor for lenalidomide treatment failure was a platelet count <280x109/l (Odds Ratio=617, P=0040). This study reveals the importance of a low baseline platelet count, karyotypic complexity and TP53 mutational status for response to lenalidomide treatment. It supports the molecular study of TP53 in MDS patients treated with lenalidomide.
Autores: Fernández, Marta; Pellagatti, A.; Di Genua, C.; et al.
Revista: BRITISH JOURNAL OF HAEMATOLOGY
ISSN 0007-1048  Vol. 163  Nº 2  2013  págs. 235 - 239
Whole exome sequencing was performed in a patient with myelodysplastic syndrome before and after progression to acute myeloid leukaemia. Mutations in several genes, including SETBP1, were identified following leukaemic transformation. Screening of 328 patients with myeloid disorders revealed SETBP1 mutations in 14 patients (4 center dot 3%), 7 of whom had -7/del(7q) and 3 had i(17)(q10), cytogenetic markers associated with shortened overall survival and increased risk of leukaemic evolution. SETBP1 mutations were frequently acquired at the time of leukaemic evolution, coinciding with increase of leukaemic blasts. These data suggest that SETBP1 mutations may play a role in MDS and chronic myelomonocytic leukaemia disease progression.
Autores: Costa, D.; Muñoz, C.; Carrió, A.; et al.
Revista: GENES CHROMOSOMES AND CANCER
ISSN 1045-2257  Vol. 52  Nº 8  2013  págs. 753 - 763
The infrequency of translocations in myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemias (CMML) makes their identification and reporting interesting for the recognition of the recurrent ones and the genes involved in these neoplasias. The aims of this study were to identify new translocations associated with MDS and CMML and to establish their frequency in a cohort of 8,016 patients from the Spanish Group of MDS database. The karyotype was evaluable in 5,654 (70%) patients. Among those, 2,014 (36%) had chromosomal abnormalities, including 213 (10%) translocations identified in 195 patients. The translocations were balanced in 183 (86%) cases and unbalanced in 30 (14%) cases. All chromosomes were found to be involved in translocations, with the single exception of the Y chromosome. The chromosomes most frequently involved were in decreasing frequency: 3, 1, 7, 2, 11, 5, 12, 6, and 17. Translocations were found in karyotypes as the unique chromosomal abnormality (33%), associated with another chromosomal abnormality (11%), as a part of a complex karyotype (17%), and as a part of a monosomal karyotype (38%). There were 155 translocations not previously described in MDS or CMML and nine of them appeared to be recurrent.
Autores: Arenillas, L.; Mallo, M.; Ramos, F.; et al.
Revista: GENES CHROMOSOMES AND CANCER
ISSN 1045-2257  Vol. 52  Nº 12  2013  págs. 1167 - 1177
Cytogenetic aberrations identified by metaphase cytogenetics (MC) have diagnostic, prognostic, and therapeutic implications in myelodysplastic syndromes (MDS). However, in some MDS patients MC study is unsuccesful. Single nucleotide polymorphism array (SNP-A) based karyotyping could be helpful in these cases. We performed SNP-A in 62 samples from bone marrow or peripheral blood of primary MDS with an unsuccessful MC study. SNP-A analysis enabled the detection of aberrations in 31 (50%) patients. We used the copy number alteration information to apply the International Prognostic Scoring System (IPSS) and we observed differences in survival between the low/intermediate-1 and intermediate-2/high risk patients. We also saw differences in survival between very low/low/intermediate and the high/very high patients when we applied the revised IPSS (IPSS-R). In conclusion, SNP-A can be used successfully in PB samples and the identification of CNA by SNP-A improve the diagnostic and prognostic evaluation of this group of MDS patients.
Autores: Sánchez-Castro, J.; Marco-Betes, V.; Gómez-Arbonés, X.; et al.
Revista: LEUKEMIA RESEARCH
ISSN 0145-2126  Vol. 37  Nº 7  2013  págs. 769 - 776
The prognosis of chromosome 17 (chr17) abnormalities in patients with primary myelodysplastic syndrome (MDS) remains unclear. The revised International Prognostic Scoring System (IPSS-R) includes these abnormalities within the intermediate cytogenetic risk group. This study assessed the impact on overall survival ( OS) and risk of acute myeloid leukemia transformation (AMLt) of chr17 abnormalities in 88 patients with primary MDS. We have compared this group with 1346 patients with primary MDS and abnormal karyotype without chr17 involved. The alterations of chr17 should be considered within group of poor prognosis. The different types of alterations of chromosome 17 behave different prognosis. The study confirms the intermediate prognostic impact of the i(17q), as stated in IPSS-R. The results of the study, however, provide valuable new information on the prognostic impact of alterations of chromosome 17 in complex karyotypes.
Autores: Cirauqui, C.; Garcia-Orti, L.; et al.
Revista: HAEMATOLOGICA-THE HEMATOLOGY JOURNAL
ISSN 0390-6078  Vol. 98  Nº 9  2013  págs. E103 - E104
Autores: Aranaz, Paula; et al.
Revista: LEUKEMIA AND LYMPHOMA
ISSN 1042-8194  Vol. 54  Nº 2  2013  págs. 428 - 431
Autores: Robles, Eloy Francisco; Parker, A.; Martínez-Useros, J.; et al.
Revista: BRITISH JOURNAL OF HAEMATOLOGY
ISSN 0007-1048  Vol. 158  Nº 6  2012  págs. 712 - 726
Using high-resolution genomic microarray analysis, a distinct genomic profile was defined in 114 samples from patients with splenic marginal zone lymphoma (SMZL). Deletion or uniparental disomy of chromosome 7q were detected in 42 of 114 (37%) SMZLs but in only nine of 170 (5%) mature B-cell lymphomas (P < 0·00001). The presence of unmutated IGHV, genomic complexity, 17p13-TP53 deletion and 8q-MYC gain, but not 7q deletion, correlated with shorter overall survival of SMZL patients. Mapping studies narrowed down a commonly deleted region of 2·7 Mb in 7q32.1-q32.2 spanning a region between the SND1 and COPG2 genes. High-throughput sequencing analysis of the 7q32-deleted segment did not identify biallelic deletions/insertions or clear pathogenic gene mutations, but detected six nucleotide changes in IRF5 (n = 2), TMEM209 (n = 2), CALU (n = 1) and ZC3HC1 (n = 1) not found in healthy individuals. Comparative expression analysis found a fourfold down-regulation of IRF5 gene in lymphomas with 7q32 deletion versus non-deleted tumours (P = 0·032). Ectopic expression of IRF5 in marginal-zone lymphoma cells decreased proliferation and increased apoptosis in vitro, and impaired lymphoma development in vivo. These results show that cryptic deletions, insertions and/or point mutations inactivating genes within 7q32 are not common in SMZL, and suggest that IRF5 may be a haploinsufficient tumour suppressor in this lymphoma entity.
Autores: Pérez, C.; Martínez, Nicolás; Martín Subero, J. I.; et al.
Revista: PLOS ONE
ISSN 1932-6203  Vol. 7  Nº 2  2012  págs. e31605
Chronic myelomonocytic leukemia (CMML) has recently been associated with a high incidence of diverse mutations in genes such as TET2 or EZH2 that are implicated in epigenetic mechanisms. We have performed genome-wide DNA methylation arrays and mutational analysis of TET2, IDH1, IDH2, EZH2 and JAK2 in a group of 24 patients with CMML. 249 genes were differentially methylated between CMML patients and controls. Using Ingenuity pathway analysis, we identified enrichment in a gene network centered around PLC, JNK and ERK suggesting that these pathways, whose deregulation has beenrecently described in CMML, are affected by epigenetic mechanisms. Mutations of TET2, JAK2 and EZH2 were found in 15 patients (65%), 4 patients (17%) and 1 patient (4%) respectively while no mutations in the IDH1 and IDH2 genes were identified. Interestingly, patients with wild type TET2 clustered separately from patients with TET2 mutations, showed a higher degree of hypermethylation and were associated with higher risk karyotypes. Our results demonstrate the presence of aberrant DNA methylation in CMML and identifies TET2 mutant CMML as a biologically distinct disease subtype with a different epigenetic profile.
Autores: Agirre, X; Abizanda, Gloria María; et al.
Revista: LEUKEMIA
ISSN 0887-6924  Vol. 26  Nº 7  2012  págs. 1517 - 1526
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(-/-)gamma c(-/-) 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(-/-)gamma c(-/-) 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.
Autores: Maiques-Diaz, A.; Chou, F. S.; Wunderlich, M.; et al.
Revista: LEUKEMIA
ISSN 0887-6924  Vol. 26  Nº 6  2012  págs. 1329 - 1337
The AML1-ETO fusion protein, which is present in 10-15% of cases of acute myeloid leukemia, is known to repress myeloid differentiation genes through DNA binding and recruitment of chromatin-modifying proteins and transcription factors in target genes. ChIP-chip analysis of human hematopoietic stem/progenitor cells transduced with the AML1-ETO fusion gene enabled us to identify 1168 AML1-ETO target genes, 103 of which were co-occupied by histone deacetylase 1 (HDAC1) and had lost the hyperacetylation mark at histone H4, and 264 showed a K9 trimethylation at histone H3. Enrichment of genes involved in hematopoietic differentiation and in specific signaling pathways was observed in the presence of these epigenetic modifications associated with an 'inactive' chromatin status. Furthermore, AML1-ETO target genes had a significant correlation between the chromatin marks studied and transcriptional silencing. Interestingly, AML1 binding sites were absent on a large number of selected AML1-ETO promoters and an Sp1 binding site was found in over 50% of them. Reversible silencing induced by the fusion protein in the presence of AML1 and/or Sp1 transcription factor binding site was confirmed. Therefore, this study provides a global analysis of AML1-ETO functional chromatin modifications and identifies the important role of Sp1 in the DNA binding pattern of AML1-ETO, suggesting a role for Sp1-targeted therapy in this leukemia subtype.
Autores: Fernández, Marta; Yip, B. H.; Pellagatti, A.; et al.
Revista: PLOS ONE
ISSN 1932-6203  Vol. 7  Nº 8  2012  págs. e42334
Acute myeloid leukemia patients with normal cytogenetics (CN-AML) account for almost half of AML cases. We aimed to study the frequency and relationship of a wide range of genes previously reported as mutated in AML (ASXL1, NPM1, FLT3, TET2, IDH1/2, RUNX1, DNMT3A, NRAS, JAK2, WT1, CBL, SF3B1, TP53, KRAS and MPL) in a series of 84 CN-AML cases. The most frequently mutated genes in primary cases were NPM1 (60.8%) and FLT3 (50.0%), and in secondary cases ASXL1 (48.5%) and TET2 (30.3%). We showed that 85% of CN-AML patients have mutations in at least one of ASXL1, NPM1, FLT3, TET2, IDH1/2 and/or RUNX1. Serial samples from 19 MDS/CMML cases that progressed to AML were analyzed for ASXL1/TET2/IDH1/2 mutations; seventeen cases presented mutations of at least one of these genes. However, there was no consistent pattern in mutation acquisition during disease progression. This report concerns the analysis of the largest number of gene mutations in CN-AML studied to date, and provides insight into the mutational profile of CN-AML.
Autores: García-Orti, L.; Cirauqui, C.; et al.
Revista: PLOS ONE
ISSN 1932-6203  Vol. 7  Nº 10  2012  págs. e47717
Background: Deregulated miRNA expression plays a crucial role in carcinogenesis. Recent studies show different mechanisms leading to miRNA deregulation in cancer; however, alterations affecting miRNAs by DNA copy number variations (CNV) remain poorly studied. Results: Our integrative analysis including data from high resolution SNPs arrays, mRNA expression arrays, and miRNAs expression profiles in 16 myeloid cell lines highlights that CNV are alternative mechanisms to deregulate the expression of miRNAs in acute myeloid leukemia (AML), and represent a novel approach to identify novel candidate genes involved in AML. We found association between the expression levels of 19 miRNAs and CNVs affecting their loci. Functional analysis showed that NF1 is a direct target of miR-370, and that overexpression of miR-370 has similar effects that NF1 inactivation, increasing proliferation and colony formation in AML cells. Moreover, real time RT-PCR showed that NF1 downregulation is a recurrent event in AML (30.8%), and western blot analysis confirmed this result. MiR-370 overexpression and deletions affecting the NF1 locus were identified as alternative mechanisms to downregulate NF1. Conclusions: NF1 downregulation is a common event in AML, and both deletions in the NF1 locus and overexpression of miR-370 are alternative mechanisms to downregulate NF1 in this disease. Our results suggest a leukemogenic role of miR-370 through NF1 downregulation in AML cells. Since NF1 deficiency leads to RAS activation, patients with AML and overexpression of miR-370 may potentially benefit from additional treatment with either RAS or mTOR inhibitors.
Autores: Navarro, A.; Clot, G.; Royo, C.; et al.
Revista: CANCER RESEARCH
ISSN 0008-5472  Vol. 72  Nº 20  2012  págs. 5307 - 5316
Mantle cell lymphoma (MCL) is a heterogeneous disease with most patients following an aggressive clinical course, whereas others having an indolent behavior. We conducted an integrative and multidisciplinary analysis of 177 MCL to determine whether the immunogenetic features of the clonotypic B-cell receptors (BcR) may identify different subsets of tumors. Truly unmutated (100% identity) IGHV genes were found in 24% cases, 40% were minimally/borderline mutated (99.9%-97%), 19% significantly mutated (96.9%-95%), and 17% hypermutated (<95%). Tumors with high or low mutational load used different IGHV genes, and their gene expression profiles were also different for several gene pathways. A gene set enrichment analysis showed that MCL with high and low IGHV mutations were enriched in memory and naive B-cell signatures, respectively. Furthermore, the highly mutated tumors had less genomic complexity, were preferentially SOX11-negative, and showed more frequent nonnodal disease. The best cut-off of germline identity of IGHV genes to predict survival was 97%. Patients with high and low mutational load had significant different outcome with 5-year overall survival (OS) of 59% and 40%, respectively (P = 0.004). Nodal presentation and SOX11 expression also predicted for poor OS. In a multivariate analysis, IGHV gene status and SOX11 expression were independent risk factors. In conclusion, these observations suggest the idea that MCL with mutated IGHV, SOX11-negativity, and nonnodal presentation correspond to a subtype of the disease with more indolent behavior.
Autores: Maicas, M.; Vázquez, Iria; Vicente, Eva; et al.
Revista: ONCOGENE
ISSN 0950-9232  Vol. 32  Nº 16  2012  págs.  2069 - 2078
The EVI1 gene (3q26) codes for a transcription factor with important roles in normal hematopoiesis and leukemogenesis. High expression of EVI1 is a negative prognostic indicator of survival in acute myeloid leukemia (AML) irrespective of the presence of 3q26 rearrangements. However, the only known mechanisms that lead to EVI1 overexpression are 3q aberrations, and the MLL-ENL oncoprotein, which activates the transcription of EVI1 in hematopoietic stem cells. Our aim was to characterize the functional promoter region of EVI1, and to identify transcription factors involved in the regulation of this gene. Generation of seven truncated constructs and luciferase reporter assays allowed us to determine a 318-bp region as the minimal promoter region of EVI1. Site-directed mutagenesis and chromatin immunoprecipitation (ChIP) assays identified RUNX1 and ELK1 as putative transcription factors of EVI1. Furthermore, knockdown of RUNX1 and ELK1 led to EVI1 downregulation, and their overexpression to upregulation of EVI1. Interestingly, in a series of patient samples with AML at diagnosis, we found a significant positive correlation between EVI1 and RUNX1 at protein level. Moreover, we identified one of the roles of RUNX1 in the activation of EVI1 during megakaryocytic differentiation. EVI1 knockdown significantly inhibited the expression of megakaryocytic markers after treating K562 cells with TPA, as happens when knocking down RUNX1. In conclusion, we define the minimal promoter region of EVI1 and demonstrate that RUNX1 and ELK1, two proteins with essential functions in hematopoiesis, regulate EVI1 in AML. Furthermore, our results show that one of the mechanisms by which RUNX1 regulates the transcription of EVI1 is by acetylation of the histone H3 on its promoter region. This study opens new directions to further understand the mechanisms of EVI1 overexpressing leukemias.
Autores: Beltrán E; Richter, José Ángel; et al.
Revista: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
ISSN 0027-8424  Vol. 108  Nº 30  2011  págs. 12461 - 12466
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.
Autores: Rodriguez, Paula; Román-Gómez, J.; et al.
Revista: BRITISH JOURNAL OF HAEMATOLOGY
ISSN 0007-1048  Vol. 155  Nº 1  2011  págs. 73 - 83
The role of epigenetic mechanisms in the regulation of microRNAs (miRNAs) with a tumour-suppressor function in human neoplasms has recently been established. Several miRNAs have been found to be inappropriately regulated by DNA methylation in patients with acute lymphoblastic leukaemia (ALL). We analysed the methylation status of the three members of the MIR9 family (MIR9-1, MIR9-2 and MIR9-3) in a uniformly treated cohort of 200 newly diagnosed ALLs. MIR9 was methylated in 54% of the patients and was associated with downregulation of MIR9 (P < 0.01). Hypermethylation of MIR9 was an independent prognostic factor for disease-free survival, overall survival and event-free survival in a multivariate analysis (P < 0 01). Epigenetic downregulation of MIR9 induced upregulation of its targets, FGFR1 and CDK6, while treatment of ALL cells with FGFR1 (PD-173074) and CDK6 (PD-0332991) inhibitors induced a decrease in cell proliferation and an increase in apoptosis of ALL cells. Our results indicate that the MIR9 family is involved in the pathogenesis and clinical behaviour of ALL and provide the basis for new therapeutic strategies in the treatment of ALL, targeting the epigenetic regulation of miRNAs and/or the FGFR1 or CDK6-RB pathway directly
Autores: García-Orti, L.; Cirauqui, C.; et al.
Revista: LEUKEMIA
ISSN 0887-6924  Vol. 25  Nº 4  2011  págs. 606 - 614
Protein phosphatase 2A (PP2A) is a human tumor suppressor that inhibits cellular transformation by regulating the activity of several signaling proteins critical for malignant cell behavior. PP2A has been described as a potential therapeutic target in chronic myeloid leukemia, Philadelphia chromosome-positive acute lymphoblastic leukemia and B-cell chronic lymphocytic leukemia. Here, we show that PP2A inactivation is a recurrent event in acute myeloid leukemia (AML), and that restoration of PP2A phosphatase activity by treatment with forskolin in AML cells blocks proliferation, induces caspase-dependent apoptosis and affects AKT and ERK1/2 activity. Moreover, treatment with forskolin had an additive effect with Idarubicin and Ara-c, drugs used in standard induction therapy in AML patients. Analysis at protein level of the PP2A activation status in a series of patients with AML at diagnosis showed PP2A hyperphosphorylation in 78% of cases (29/37). In addition, we found that either deregulated expression of the endogenous PP2A inhibitors SET or CIP2A, overexpression of SETBP1, or downregulation of some PP2A subunits, might be contributing to PP2A inhibition in AML. In conclusion, our results show that PP2A inhibition is a common event in AML cells and that PP2A activators, such as forskolin or FTY720, could represent potential novel therapeutic targets in AML.
Autores: Javierre, B. M.; Rodríguez-Ubreba, J.; Al-Shahrour, F.; et al.
Revista: MOLECULAR CANCER RESEARCH
ISSN 1541-7786  Vol. 9  Nº 8  2011  págs. 1139 - 1151
Transcription factors are common targets of epigenetic inactivation in human cancer. Promoter hypermethylation and subsequent silencing of transcription factors can lead to further deregulation of their targets. In this study, we explored the potential epigenetic deregulation in cancer of Ikaros family genes, which code for essential transcription factors in cell differentiation and exhibit genetic defects in hematologic neoplasias. Unexpectedly, our analysis revealed that Ikaros undergoes very specific promoter hypermethylation in colorectal cancer, including in all the cell lines studied and around 64% of primary colorectal adenocarcinomas, with increasing proportions in advanced Duke's stages. Ikaros hypermethylation occurred in the context of a novel long-range epigenetic silencing (LRES) region. Reintroduction of Ikaros in colorectal cancer cells, ChIP-chip analysis, and validation in primary samples led us to identify a number of direct targets that are possibly related with colorectal cancer progression. Our results not only provide the first evidence that LRES can have functional specific effects in cancer but also identify several deregulated Ikaros targets that may contribute to progression in colorectal adenocarcinoma.
Autores: Agirre, X; Martín-Palanco, V.; et al.
Revista: PLOS ONE
ISSN 1932-6203  Vol. 6  Nº 2  2011  págs. e17012
Aberrant DNA methylation is one of the most frequent alterations in patients with Acute Lymphoblastic Leukemia (ALL). Using methylation bead arrays we analyzed the methylation status of 807 genes implicated in cancer in a group of ALL samples at diagnosis (n¿=¿48). We found that 154 genes were methylated in more than 10% of ALL samples. Interestingly, the expression of 13 genes implicated in the TP53 pathway was downregulated by hypermethylation. Direct or indirect activation of TP53 pathway with 5-aza-2'-deoxycitidine, Curcumin or Nutlin-3 induced an increase in apoptosis of ALL cells. The results obtained with the initial group of 48 patients was validated retrospectively in a second cohort of 200 newly diagnosed ALL patients. Methylation of at least 1 of the 13 genes implicated in the TP53 pathway was observed in 78% of the patients, which significantly correlated with a higher relapse (p¿=¿0.001) and mortality (p<0.001) rate being an independent prognostic factor for disease-free survival (DFS) (p¿=¿0.006) and overall survival (OS) (p¿=¿0.005) in the multivariate analysis. All these findings indicate that TP53 pathway is altered by epigenetic mechanisms in the majority of ALL patients and correlates with prognosis. Treatments with compounds that may reverse the epigenetic abnormalities or activate directly the p53 pathway represent a new therapeutic alternative for patients with ALL.
Autores: Vegliante, M. C.; Royo, C.; Palomero, J.; et al.
Revista: PLOS ONE
ISSN 1932-6203  Vol. 6  Nº 6  2011  págs. e21382
Recent studies have shown aberrant expression of SOX11 in various types of aggressive B-cell neoplasms. To elucidate the molecular mechanisms leading to such deregulation, we performed a comprehensive SOX11 gene expression and epigenetic study in stem cells, normal hematopoietic cells and different lymphoid neoplasms. We observed that SOX11 expression is associated with unmethylated DNA and presence of activating histone marks (H3K9/14Ac and H3K4me3) in embryonic stem cells and some aggressive B-cell neoplasms. In contrast, adult stem cells, normal hematopoietic cells and other lymphoid neoplasms do not express SOX11. Such repression was associated with silencing histone marks H3K9me2 and H3K27me3. The SOX11 promoter of non-malignant cells was consistently unmethylated whereas lymphoid neoplasms with silenced SOX11 tended to acquire DNA hypermethylation. SOX11 silencing in cell lines was reversed by the histone deacetylase inhibitor SAHA but not by the DNA methyltransferase inhibitor AZA. These data indicate that, although DNA hypermethylation of SOX11 is frequent in lymphoid neoplasms, it seems to be functionally inert, as SOX11 is already silenced in the hematopoietic system. In contrast, the pathogenic role of SOX11 is associated with its de novo expression in some aggressive lymphoid malignancies, which is mediated by a shift from inactivating to activating histone modifications.
Autores: Vázquez, Iria; Cervera, J.; et al.
Revista: HAEMATOLOGICA-THE HEMATOLOGY JOURNAL
ISSN 0390-6078  Vol. 96  Nº 10  2011  págs. 1448 - 1456
Our results identify EVI1 over-expression as a poor prognostic marker in a large, independent cohort of acute myeloid leukemia patients less than 65 years old, and show that the total absence of EVI1 expression has a prognostic impact on the outcome of such patients. Furthermore, we demonstrated for the first time that an aberrant epigenetic pattern involving DNA methylation, H3 and H4 acetylation, and trimethylation of histone H3 lysine 4 and histone H3 lysine 27 might play a role in the transcriptional regulation of EVI1 in acute myeloid leukemia. This study opens new avenues for a better understanding of the regulation of EVI1 expression at a transcriptional level.
Autores: Mallo, M.; Cervera, J.; Schanz, J.; et al.
Revista: LEUKEMIA
ISSN 0887-6924  Vol. 25  Nº 1  2011  págs. 110 - 120
This cooperative study assessed prognostic factors for overall survival (OS) and risk of transformation to acute myeloid leukemia (AML) in 541 patients with de novo myelodysplastic syndrome (MDS) and deletion 5q. Additional chromosomal abnormalities were strongly related to different patients' characteristics. In multivariate analysis, the most important predictors of both OS and AML transformation risk were number of chromosomal abnormalities (P<0.001 for both outcomes), platelet count (P<0.001 and P = 0.001, respectively) and proportion of bone marrow blasts (P<0.001 and P = 0.016, respectively). The number of chromosomal abnormalities defined three risk categories for AML transformation (del(5q), del(5q) + 1 and del(5q) + >= 2 abnormalities) and two for OS (one group: del(5q) and del(5q) + 1; and del(5q) + >= 2 abnormalities, as the other one); with a median survival time of 58.0 and 6.8 months, respectively. Platelet count (P = 0.001) and age (P = 0.034) predicted OS in patients with '5q-syndrome'. This study demonstrates the importance of additional chromosomal abnormalities in MDS patients with deletion 5q, challenges the current '5q-syndrome' definition and constitutes a useful reference series to properly analyze the results of clinical trials in these patients.
Autores: Barragán, E.; Montesinos, P.; Camos, M.; et al.
Revista: HAEMATOLOGICA-THE HEMATOLOGY JOURNAL
ISSN 0390-6078  Vol. 96  Nº 10  2011  págs. 1470 - 1477
BACKGROUND: Fms-like tyrosine kinase-3 (FLT3) gene mutations are frequent in acute promyelocytic leukemia but their prognostic value is not well established. DESIGN AND METHODS: We evaluated FLT3-internal tandem duplication and FLT3-D835 mutations in patients treated with all-trans retinoic acid and anthracycline-based chemotherapy enrolled in two subsequent trials of the Programa de Estudio y Tratamiento de las Hemopatías Malignas (PETHEMA) and Hemato-Oncologie voor Volwassenen Nederland (HOVON) groups between 1996 and 2005. RESULTS: FLT3-internal tandem duplication and FLT3-D835 mutation status was available for 306 (41%) and 213 (29%) patients, respectively. Sixty-eight (22%) and 20 (9%) patients had internal tandem duplication and D835 mutations, respectively. Internal tandem duplication was correlated with higher white blood cell and blast counts, lactate dehydrogenase, relapse-risk score, fever, hemorrhage, coagulopathy, BCR3 isoform, M3 variant subtype, and expression of CD2, CD34, human leukocyte antigen-DR, and CD11b surface antigens. The FLT3-D835 mutation was not significantly associated with any clinical or biological characteristic. Univariate analysis showed higher relapse and lower survival rates in patients with a FLT3-internal tandem duplication, while no impact was observed in relation to FLT3-D835. The prognostic value of the FLT3-internal tandem duplication was not retained in the multivariate analysis. CONCLUSIONS: FLT3-internal tandem duplication mutations are associated with several hematologic features in acute promyelocytic leukemia, in particular with high white blood cell counts, but we were unable to demonstrate an independent prognostic value in patients with acute promyelocytic leukemia treated with all-trans retinoic acid and anthracycline-based regimens.
Autores: García Orti, L.; Cirauqui, C.; et al.
Revista: HAEMATOLOGICA-THE HEMATOLOGY JOURNAL
ISSN 0390-6078  Vol. 97  Nº 4  2011  págs. 543 - 550
Protein phosphatase 2A is a novel potential therapeutic target in several types of chronic and acute leukemia, and its inhibition is a common event in acute myeloid leukemia. Upregulation of SET is essential to inhibit protein phosphatase 2A in chronic myeloid leukemia, but its importance in acute myeloid leukemia has not yet been explored. Design and Methods We quantified SET expression by real time reverse transcriptase polymerase chain reaction in 214 acute myeloid leukemia patients at diagnosis. Western blot was performed in acute myeloid leukemia cell lines and in 16 patients' samples. We studied the effect of SET using cell viability assays. Bioinformatics analysis of the SET promoter, chromatin immunoprecipitation, and luciferase assays were performed to evaluate the transcriptional regulation of SET. Results SET overexpression was found in 60/214 patients, for a prevalence of 28%. Patients with SET overexpression had worse overall survival (P<0.01) and event-free survival (P<0.01). Deregulation of SET was confirmed by western blot in both cell lines and patients' samples. Functional analysis showed that SET promotes proliferation, and restores cell viability after protein phosphatase 2A overexpression. We identified EVI1 overexpression as a mechanism involved in SET deregulation in acute myeloid leukemia cells. Conclusions These findings suggest that SET overexpression is a key mechanism in the inhibition of PP2A in acute myeloid leukemia, and that EVI1 overexpression contributes to the deregulation of SET. Furthermore, SET over-expression is associated with a poor outcome in acute myeloid leukemia, and it can be used to identify a subgroup of patients who could benefit from future treatments based on PP2A activators.
Autores: Such, E.; Cervera, J.; Costa, D.; et al.
Revista: HAEMATOLOGICA-THE HEMATOLOGY JOURNAL
ISSN 0390-6078  Vol. 96  Nº 3  2011  págs. 375 - 383
Background The prognostic value of cytogenetic findings in chronic myelomonocytic leukemia is unclear. Our purpose was to evaluate the independent prognostic impact of cytogenetic abnormalities in a large series of patients with chronic myelomonocytic leukemia included in the database of the Spanish Registry of Myelodysplastic Syndromes. Design and Methods We studied 414 patients with chronic myelomonocytic leukemia according to WHO criteria and with a successful conventional cytogenetic analysis at diagnosis. Different patient and disease characteristics were examined by univariate and multivariate methods to establish their relationship with overall survival and evolution to acute myeloid leukemia. Results Patients with abnormal karyotype (110 patients, 27%) had poorer overall survival (P=0.001) and higher risk of acute myeloid leukemia evolution (P=0.010). Based on outcome analysis, three cytogenetic risk categories were identified: low risk (normal karyotype or loss of Y chromosome as a single anomaly), high risk (presence of trisomy 8 or abnormalities of chromosome 7, or complex karyotype), and intermediate risk (all other abnormalities). Overall survival at five years for patients in the low, intermediate, and high risk cytogenetic categories was 35%, 26%, and 4%, respectively (P < 0.001). Multivariate analysis confirmed that this new CMML-specific cytogenetic risk stratification was an independent prognostic variable for overall survival (P=0.001). Additionally, patients belonging to the high-risk cytogenetic category also had a higher risk of acute myeloid leukemia evolution on univariate (P=0.001) but not multivariate analysis. Conclusions Cytogenetic findings have a strong prognostic impact in patients with chronic myelomonocytic leukemia.
Autores: Malumbres, Raquel; Román-Gómez, J.; Bobadilla, Miriam; et al.
Revista: HAEMATOLOGICA-THE HEMATOLOGY JOURNAL
ISSN 0390-6078  Vol. 96  Nº 7  2011  págs. 980 - 986
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 sub-types. 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.
Autores: Vicente, C.; Vázquez, Iria; Conchillo, Ana; et al.
Revista: LEUKEMIA
ISSN 0887-6924  Vol. 26  Nº 3  2011  págs. 550 - 554
Autores: Ammatuna, E.; Panetta, P.; Agirre, X; et al.
Revista: HAEMATOLOGICA-THE HEMATOLOGY JOURNAL
ISSN 0390-6078  Vol. 96  Nº 5  2011  págs. 784 - 785
Autores: Robles, Eloy Francisco; Akasaka, T.; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 118  Nº 21  2011  págs. 119 - 120
Autores: Martínez, José Ángel; Richter, José Ángel; et al.
Revista: ANNALS OF ONCOLOGY
ISSN 0923-7534  Vol. 22  Nº Supl 4  2011  págs. 127
Autores: Agirre, X; Abizanda, Gloria María; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 118  Nº 21  2011  págs. 660
Autores: Blanco, F. J.; García-Orti, L.; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 115  Nº 3  2010  págs. 615 - 625
Acute myeloid leukemias (AMLs) result from multiple genetic alterations in hematopoietic stem cells. We describe a novel t(12; 18)(p13;q12) involving ETV6 in a patient with AML. The translocation resulted in overexpression of SETBP1 (18q12), located close to the breakpoint. Overexpression of SETBP1 through retroviral insertion has been reported to confer growth advantage in hematopoietic progenitor cells. We show that SETBP1 overexpression protects SET from protease cleavage, increasing the amount of full-length SET protein and leading to the formation of a SETBP1 SET-PP2A complex that results in PP2A inhibition, promoting proliferation of the leukemic cells. The prevalence of SETBP1 overexpression in AML at diagnosis (n=192) was 27.6% and was associated with unfavorable cytogenetic prognostic group, monosomy 7, and EVI1 overexpression (P <.01). Patients with SETBP1 overexpression had a significantly shorter overall survival, and the prognosis impact was remarkably poor in patients older than 60 years in both overall survival (P=.015) and event-free survival (P=.015). In summary, our data show a novel leukemogenic mechanism through SETBP1 overexpression; moreover, multivariate analysis confirms the negative prognostic impact of SETBP1 overexpression in AML, especially in elderly patients, where it could be used as a predictive factor in any future clinical trials with PP2A activators.
Autores: Espinet, B.; Salaverria, I.; Beà, S.; et al.
Revista: GENES CHROMOSOMES AND CANCER
ISSN 1045-2257  Vol. 49  Nº 5  2010  págs. 439 - 451
Mantle cell lymphoma (MCL) is a mature B-cell neoplasm with an aggressive behavior, characterized by the t(11;14)(q13;q32). Several secondary genetic abnormalities with a potential role in the oncogenic process have been described. Studies of large MCL series using conventional cytogenetics, and correlating with proliferation and survival, are scarce. We selected 145 MCL cases at diagnosis, displaying an aberrant karyotype, from centers belonging to the Spanish Cooperative Group for Hematological Cytogenetics. Histological subtype, proliferative index and survival data were ascertained. Combined cytogenetic and molecular analyses detected CCNDI translocations in all cases, mostly t(I I;14)(q13;q32). Secondary aberrations were present in 58% of patients, the most frequent being deletions of 1p, 13q and 17p, 10p alterations and 3q gains. The most recurrent breakpoints were identified at I p31-32, I p21-22, 17p13, and 1p36. Aggressive blastoid/pleomorphic variants displayed a higher karyotypic complexity, a higher frequency of I p and 17p deletions and 10p alterations, a higher proliferation index and poor survival. Gains of 3q and 13q and 17p 13 losses were associated with reduced survival times. Interestingly, gains of 3q and 17p losses added prognostic significance to the morphology in a multi-variate analysis. Our findings confirm previous observations indicating that proliferation index, morphology and several secondary genetic alterations (3q gains and 13q and 17p losses) have prognostic value in patients with MCL. Additionally, we observed that 3q gains and 17p losses detected by conventional cytogenetics are proliferation-independent prognostic markers indicating poor outcome.
Autores: Score, J.; Calasanz, María José; Ottman, O.; et al.
Revista: LEUKEMIA
ISSN 0887-6924  Vol. 24  Nº 10  2010  págs. 1742 - 1750
We sought to understand the genesis of the t(9;22) by characterizing genomic breakpoints in chronic myeloid leukemia (CML) and BCR-ABL-positive acute lymphoblastic leukemia (ALL). BCR-ABL breakpoints were identified in p190 ALL (n = 25), p210 ALL (n = 25) and p210 CML (n = 32); reciprocal breakpoints were identified in 54 cases. No evidence for significant clustering and no association with sequence motifs was found except for a breakpoint deficit in repeat regions within BCR for p210 cases. Comparison of reciprocal breakpoints, however, showed differences in the patterns of deletion/insertions between p190 and p210. To explore the possibility that recombinase-activating gene (RAG) activity might be involved in ALL, we performed extra-chromosomal recombination assays for cases with breakpoints close to potential cryptic recombination signal sequence (cRSS) sites. Of 13 ALL cases tested, 1/10 with p190 and 1/3 with p210 precisely recapitulated the forward BCR-ABL breakpoint and 1/10 with p190 precisely recapitulated the reciprocal breakpoint. In contrast, neither of the p210 CMLs tested showed functional cRSSs. Thus, although the t(9;22) does not arise from aberrant variable (V), joining (J) and diversity (D) (V(D) J) recombination, our data suggest that in a subset of ALL cases RAG might create one of the initiating double-strand breaks.
Autores: Ormazábal, Cristina; et al.
Revista: LEUKEMIA AND LYMPHOMA
ISSN 1042-8194  Vol. 51  Nº 9  2010  págs. 1720 - 1726
Hematological malignancies with eosinophilia are often associated with fusions in PDGFRA, PDGFRB, or FGFR1 genes. RT-PCR has proved to be useful for finding new PDGFRA gene fusions, but some studies have shown overexpression of the TK domain which cannot be explained by the existence of such aberrations. This fact could be related to the expression of alternative PDGFRA transcripts. We show that quantification of the expression of three different PDGFRA fragments discriminates between PDGFRA alternative transcripts and fusion genes, and we have tested this novel methodological approach in a group of eosinophilia cases. Our data show that alternative PDGFRA transcripts should be taken into account when screening for PDGFRA aberrations, such as gene fusions, by RT-PCR. Expression from an internal PDGFRA promoter seems to be a frequent event, in both normal and leukemic samples, and is probably related to physiological conditions, but it could have a role in other tumors. Even so, we show that our RQ-PCR methodology can discriminate expression of alternative transcripts from the presence of X-PDGFRA fusion genes.
Autores: Alvarez, S.; Suela, J.; Valencia, A.; et al.
Revista: PLOS ONE
ISSN 1932-6203  Vol. 5  Nº 8  2010  págs. e12197
Background: Aberrant promoter DNA methylation has been shown to play a role in acute myeloid leukemia (AML) pathophysiology. However, further studies to discuss the prognostic value and the relationship of the epigenetic signatures with defined genomic rearrangements in acute myeloid leukemia are required. Methodology/Principal Findings: We carried out high-throughput methylation profiling on 116 de novo AML cases and we validated the significant biomarkers in an independent cohort of 244 AML cases. Methylation signatures were associated with the presence of a specific cytogenetic status. In normal karyotype cases, aberrant methylation of the promoter of DBC1 was validated as a predictor of the disease-free and overall survival. Furthermore, DBC1 expression was significantly silenced in the aberrantly methylated samples. Patients with chromosome rearrangements showed distinct methylation signatures. To establish the role of fusion proteins in the epigenetic profiles, 20 additional samples of human hematopoietic stem/progenitor cells (HSPC) transduced with common fusion genes were studied and compared with patient samples carrying the same rearrangements. The presence of MLL rearrangements in HSPC induced the methylation profile observed in the MLL-positive primary samples. In contrast, fusion genes such as AML1/ETO or CBFB/MYH11 failed to reproduce the epigenetic signature observed in the patients. Conclusions/Significance: Our study provides a comprehensive epigenetic profiling of AML, identifies new clinical markers for cases with a normal karyotype, and reveals relevant biological information related to the role of fusion proteins on the methylation signature.
Autores: Cervera, J.; Montesinos, P.; Hernández-Rivas, J. M.; et al.
Revista: HAEMATOLOGICA-THE HEMATOLOGY JOURNAL
ISSN 0390-6078  Vol. 95  Nº 3  2010  págs. 424 - 431
Background Acute promyelocytic leukemia is a subtype of acute myeloid leukemia characterized by the t(15;17). The incidence and prognostic significance of additional chromosomal abnormalities in acute promyelocytic leukemia is still a controversial matter. Design and Methods Based on cytogenetic data available for 495 patients with acute promyelocytic leukemia enrolled in two consecutive PETHEMA trials (LPA96 and LPA99), we analyzed the incidence, characteristics, and outcome of patients with acute promyelocytic leukemia with and without additional chromosomal abnormalities who had been treated with all-trans retinoic acid plus anthracycline monochemotherapy for induction and consolidation. Results Additional chromosomal abnormalities were observed in 140 patients (28%). Trisomy 8 was the most frequent abnormality (36%), followed by abn(7q) (5%). Patients with additional chromosomal abnormalities more frequently had coagulopathy (P=0.03), lower platelet counts (P=0.02), and higher relapse-risk scores (P=0.02) than their counterparts without additional abnormalities. No significant association with FLT3/ITD or other clinicopathological characteristics was demonstrated. Patients with and without additional chromosomal abnormalities had similar complete remission rates (90% and 91%, respectively). Univariate analysis showed that additional chromosomal abnormalities were associated with a lower relapse-free survival in the LPA99 trial (P=0.04), but not in the LPA96 trial. However, neither additional chromosomal abnormalities overall nor any specific abnormality was identified as an independent risk factor for relapse in multivariate analysis. Conclusions The lack of independent prognostic value of additional chromosomal abnormalities in acute promyelocytic leukemia does not support the use of alternative therapeutic strategies when such abnormalities are found.
Autores: Richter, José Ángel; Robles, Eloy Francisco; Beltrán E; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 116  Nº 14  2010  págs. 2531 - 2542
In Burkitt lymphoma/leukemia (BL), achievement of complete remission with first-line chemotherapy remains a challenging issue, as most patients who respond remain disease-free, whereas those refractory have few options of being rescued with salvage therapies. The mechanisms underlying BL chemoresistance and how it can be circumvented remain undetermined. We previously reported the frequent inactivation of the proapoptotic BIM gene in B-cell lymphomas. Here we show that BIM epigenetic silencing by concurrent promoter hypermethylation and deacetylation occurs frequently in primary BL samples and BL-derived cell lines. Remarkably, patients with BL with hypermethylated BIM presented lower complete remission rate (24% vs 79%; P = .002) and shorter overall survival (P = .007) than those with BIM-expressing lymphomas, indicating that BIM transcriptional repression may mediate tumor chemoresistance. Accordingly, by combining in vitro and in vivo studies of human BL-xenografts grown in immuno-deficient RAG2(-/-)gamma c(-/-) mice and of murine B220(+)IgM(+) B-cell lymphomas generated in E(mu)-MYC and E(mu)-MYC-BIM(+/-) transgenes, we demonstrate that lymphoma chemoresistance is dictated by BIM gene dosage and is reversible on BIM reactivation by genetic manipulation or after treatment with histone-deacetylase inhibitors. We suggest that the combination of histone-deacetylase inhibitors and high-dose chemotherapy may overcome chemoresistance, achieve durable remission, and improve survival of patients with BL.
Autores: Valeri, A.; Alonso-Ferrero, M. E.; Río, P.; et al.
Revista: PLOS ONE
ISSN 1932-6203  Vol. 5  Nº 12  2010  págs. e15525
Chronic myeloid leukemia (CML) is a malignant clonal disorder of the hematopoietic system caused by the expression of the BCR/ABL fusion oncogene. Although it is well known that CML cells are genetically unstable, the mechanisms accounting for this genomic instability are still poorly understood. Because the Fanconi anemia (FA) pathway is believed to control several mechanisms of DNA repair, we investigated whether this pathway was disrupted in CML cells. Our data show that CML cells have a defective capacity to generate FANCD2 nuclear foci, either in dividing cells or after DNA damage. Similarly, human cord blood CD34(+) cells transduced with BCR/ABL retroviral vectors showed impaired FANCD2 foci formation, whereas FANCD2 monoubiquitination in these cells was unaffected. Soon after the transduction of CD34+ cells with BCR/ABL retroviral vectors a high proportion of cells with supernumerary centrosomes was observed. Similarly, BCR/ABL induced a high proportion of chromosomal abnormalities, while mediated a cell survival advantage after exposure to DNA cross-linking agents. Significantly, both the impaired formation of FANCD2 nuclear foci, and also the predisposition of BCR/ABL cells to develop centrosomal and chromosomal aberrations were reverted by the ectopic expression of BRCA1. Taken together, our data show for the first time a disruption of the FA/BRCA pathway in BCR/ABL cells, suggesting that this defective pathway should play an important role in the genomic instability of CML by the co-occurrence of centrosomal amplification and DNA repair deficiencies.
Autores: Conchillo, Ana; Vázquez, Iria; et al.
Revista: BRITISH JOURNAL OF CANCER
ISSN 0007-0920  Vol. 103  Nº 8  2010  págs. 1292 - 1296
BAKGROUND: The EVI1(ecotropic virus integration site 1) gene codes for a zinc-finger transcription factor, whose transcriptional activation leads to a particularly aggressive form of acute myeloid leukaemia (AML). Although, EVI1 interactions with key proteins in hematopoiesis have been previously described, the precise role of this transcription factor in promoting leukaemic transformation is not completely understood. Recent works have identified specific microRNA (miRNA) signatures in different AML subgroups. However, there is no analysis of miRNAs profiles associated with EVI1 overexpression in humans. METHODS: We performed QT-RT-PCR to assess the expression of 250 miRNAs in cell lines with or without EVI1 overexpression and in patient samples. We used ChIP assays to evaluated the possible binding of EVI1 binding to the putative miRNA promoter. Proliferation of the different cell lines transfected with the anti-or pre-miRs was quantified by MTT. RESULTS: Our data showed that EVI1 expression was significantly correlated with the expression of miR-1-2 and miR-133-a-1 in established cell lines and in patient samples. ChIP assays confirmed that EVI1 binds directly to the promoter of these two miRNAs. However, only miR-1-2 was involved in abnormal proliferation in EVI1 expressing cell lines. CONCLUSIONS: Our data showed that EVI1 controls proliferation in AML through modulation of miR-1-2. This study contributes to further understand the transcriptional networks involving transcription factors and miRNAs in AML.
Autores: Salido, M.; Baró, C.; Stamatopoulos, K.; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 116  Nº 9  2010  págs. 1479 - 1488
We conducted a retrospective collaborative study to cytogenetically characterize splenic marginal zone lymphoma (SMZL) and ascertain the prognostic value of chromosomal aberrations. Of 330 cases, 72% displayed an aberrant karyotype, 53% were complex, and 29% had a single aberration. The predominant aberrations were gains of 3/3q and 12q, deletions of 7q and 6q and translocations involving 8q/1q/14q. CD5 expression was detected in 39 of 158 cases (25%). The cytogenetic makeup of the CD5(+) group differed significantly from that of the CD5(-) group. Cases with unmutated IGHV were significantly associated with deletions of 7q and TP53. A strong association was noted between usage of the IGVH1-2 and deletion 7q, 14q alterations, and abnormal karyotype. On univariate analysis, patients with more than or equal to 2 aberrations, 14q alterations, and TP53 deletions had the shortest survival; 7q deletion did not affect survival. On multivariate analysis, cytogenetic aberrations did not retain prognostic significance; the parameters negatively affecting survival were hemoglobin and age. In conclusion, the cytogenetic profile of SMZL is distinct from other B-cell lymphomas. Complexity of the karyotype, 14q aberrations, and TP53 deletions are poor prognostic indicators and may be considered together with other clinicobiologic parameters to ascertain the prognosis of SMZL.
Autores: Aranaz, Paula; Ormazábal, Cristina; et al.
Revista: CANCER GENETICS AND CYTOGENETICS
ISSN 0165-4608  Vol. 199  Nº 1  2010  págs. 1 - 8
BCR/ABL1-negative chronic myeloproliferative neoplasms (CMPNs) are a heterogeneous group of clonal hematological malignancies. Over recent years, some genetic events in tyrosine lcinase (TK) genes have been described as causal events of these diseases. To identify new genetic aberrations underlying these diseases, we used denaturing high performance liquid chromatography and fluorescence in situ hybridization (FISH) to analyze 17 genes from two receptor-TK families (III and IV) and from three cytoplasmic-TK families (Syk, Abl, and Jak) on samples from 44 BCR/ABL1-negative and JAK2(V617F)-negative CMPN patients with different clinical phenotypes. Although screening by FISH did not reveal novel chromosomal aberrations, several sequence changes were detected. None of them were frequent events, but we identified a new potential activating mutation in the FERM domain of JAK2(R340Q). None of the germline JAK2(V617F) singlenucleotide polymorphisms detected differed in distribution between patients and control subjects. In summary, data presented here show that these genes are not frequently mutated or rearranged in CMPNs, suggesting that molecular events causing these disorders must be located in other genes.
Autores: Boultwood, J.; Perry, J.; Pellagatti, A.; et al.
Revista: LEUKEMIA
ISSN 0887-6924  Vol. 24  Nº 5  2010  págs. 1062 - 1065
Autores: Azaceta, G.; Calasanz, María José; Doudril, V.; et al.
Revista: LEUKEMIA AND LYMPHOMA
ISSN 1042-8194  Vol. 51  Nº 10  2010  págs. 1941 - 1943
Autores: Vázquez, Iria; Marcotegui, Nerea; et al.
Revista: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
ISSN 0027-8424  Vol. 107  Nº 44  2010  págs. E167 - E168
Autores: Beltrán E; Richter, José Ángel; Sagardoy, A.; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 116  Nº 21  2010  págs. 338
Autores: Valeri, A.; Alonso-Ferrero, M. E.; Rio, P; et al.
Revista: HUMAN GENE THERAPY
ISSN 1043-0342  Vol. 21  Nº 10  2010  págs. 1365

ACTIVIDAD DOCENTE