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Leucemia Mieloide Aguda , Proteínas de Complejo Poro Nuclear , Proteínas de Fusión Oncogénica , Humanos , Leucemia Mieloide Aguda/genética , Proteínas de Complejo Poro Nuclear/genética , Proteínas de Fusión Oncogénica/genética , Adulto , Mutación , Estudios de Cohortes , Masculino , Femenino , Persona de Mediana EdadRESUMEN
Immune dysfunction in patients with MM affects both the innate and adaptive immune system. Molecules involved in the immune response pathways are essential to determine the ability of cancer cells to escape from the immune system surveillance. However, few data are available concerning the role of immune checkpoint molecules in predicting the myeloma control and immunological scape as mechanism of disease progression. We retrospectively analyzed the clinical impact of the CD200 genotype (rs1131199 and rs2272022) in 291 patients with newly diagnosed MM. Patients with a CD200 rs1131199 GG genotype showed a median overall survival (OS) significantly lower than those with CC+CG genotype (67.8 months versus 94.4 months respectively; p: 0.022) maintaining significance in the multivariate analysis. This effect was specially detected in patients not receiving an autologous stem cell transplant (auto-SCT) (p < 0.001). In these patients the rs1131199 GG genotype negatively influenced in the mortality not related with the progression of MM (p: 0.02) mainly due to infections events.
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Mieloma Múltiple , Humanos , Sistema Inmunológico/metabolismo , Mieloma Múltiple/genética , Mieloma Múltiple/terapia , Mieloma Múltiple/diagnóstico , Pronóstico , Estudios Retrospectivos , Trasplante de Células MadreRESUMEN
Leukemic stem cells (LSCs) possess similar characteristics to normal hematopoietic stem cells, including self-renewal capacity, quiescence, ability to initiate leukemia, and drug resistance. These cells play a significant role in leukemia relapse, persisting even after apparent remission. LSCs were first described in 1994 by Lapidot et al. Although they have been extensively studied in acute leukemia, more LSC research is still needed in chronic lymphocytic leukemia (CLL) to understand if reduced apoptosis in mature cells should still be considered as the major cause of this disease. Here, we provide new evidence suggesting the existence of stem-like cell populations in CLL, which may help to understand the disease as well as to develop effective treatments. In this study, we identified a potential leukemic stem cell subpopulation using the tetraploid CLL cell line I83. This subpopulation is characterized by diploid cells that were capable of generating the I83 tetraploid population. Furthermore, we adapted a novel flow cytometry analysis protocol to detect CLL subpopulations with stem cell properties in peripheral blood samples and primary cultures from CLL patients. These cells were identified by their co-expression of CD19 and CD5, characteristic markers of CLL cells. As previously described, increased alkaline phosphatase (ALP) activity is indicative of stemness and pluripotency. Moreover, we used this method to investigate the potential synergistic effect of curcumin in combination with fludarabine and ibrutinib to deplete this subpopulation. Our results confirmed the effectiveness of this ALP-based analysis protocol in detecting and monitoring leukemic stem-like cells in CLL. This analysis also identified limitations in eradicating these populations using in vitro testing. Furthermore, our findings demonstrated that curcumin significantly enhanced the effects of fludarabine and ibrutinib on the leukemic fraction, exhibiting synergistic effects (combination drug index, CDI 0.97 and 0.37, respectively). Our results lend support to the existence of potential stem-like populations in CLL cell lines, and to the idea that curcumin could serve as an effective adjuvant in therapies aimed at eliminating these populations and improving treatment efficacy.
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Adenina/análogos & derivados , Curcumina , Leucemia Linfocítica Crónica de Células B , Piperidinas , Vidarabina/análogos & derivados , Humanos , Leucemia Linfocítica Crónica de Células B/metabolismo , Curcumina/farmacología , Curcumina/uso terapéutico , TetraploidíaRESUMEN
Chromosomal instability (CIN) lies at the core of cancer development leading to aneuploidy, chromosomal copy-number heterogeneity (chr-CNH) and ultimately, unfavorable clinical outcomes. Despite its ubiquity in cancer, the presence of CIN in childhood B-cell acute lymphoblastic leukemia (cB-ALL), the most frequent pediatric cancer showing high frequencies of aneuploidy, remains unknown. Here, we elucidate the presence of CIN in aneuploid cB-ALL subtypes using single-cell whole-genome sequencing of primary cB-ALL samples and by generating and functionally characterizing patient-derived xenograft models (cB-ALL-PDX). We report higher rates of CIN across aneuploid than in euploid cB-ALL that strongly correlate with intraclonal chr-CNH and overall survival in mice. This association was further supported by in silico mathematical modeling. Moreover, mass-spectrometry analyses of cB-ALL-PDX revealed a "CIN signature" enriched in mitotic-spindle regulatory pathways, which was confirmed by RNA-sequencing of a large cohort of cB-ALL samples. The link between the presence of CIN in aneuploid cB-ALL and disease progression opens new possibilities for patient stratification and offers a promising new avenue as a therapeutic target in cB-ALL treatment.
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Aneuploidia , Leucemia-Linfoma Linfoblástico de Células Precursoras , Niño , Humanos , Animales , Ratones , Inestabilidad Cromosómica , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Progresión de la EnfermedadRESUMEN
The t(14;19)(q32;q13) often juxtaposes BCL3 with immunoglobulin heavy chain (IGH) resulting in overexpression of the gene. In contrast to other oncogenic translocations, BCL3 rearrangement (BCL3-R) has been associated with a broad spectrum of lymphoid neoplasms. Here we report an integrative whole-genome sequence, transcriptomic, and DNA methylation analysis of 13 lymphoid neoplasms with BCL3-R. The resolution of the breakpoints at single base-pair revealed that they occur in two clusters at 5' (n=9) and 3' (n=4) regions of BCL3 associated with two different biological and clinical entities. Both breakpoints were mediated by aberrant class switch recombination of the IGH locus. However, the 5' breakpoints (upstream) juxtaposed BCL3 next to an IGH enhancer leading to overexpression of the gene whereas the 3' breakpoints (downstream) positioned BCL3 outside the influence of the IGH and were not associated with its expression. Upstream BCL3-R tumors had unmutated IGHV, trisomy 12, and mutated genes frequently seen in chronic lymphocytic leukemia (CLL) but had an atypical CLL morphology, immunophenotype, DNA methylome, and expression profile that differ from conventional CLL. In contrast, downstream BCL3-R neoplasms were atypical splenic or nodal marginal zone lymphomas (MZL) with mutated IGHV, complex karyotypes and mutated genes typical of MZL. Two of the latter four tumors transformed to a large B-cell lymphoma. We designed a novel fluorescence in situ hybridization assay that recognizes the two different breakpoints and validated these findings in 17 independent tumors. Overall, upstream or downstream breakpoints of BCL3-R are mainly associated with two subtypes of lymphoid neoplasms with different (epi)genomic, expression, and clinicopathological features resembling atypical CLL and MZL, respectively.
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Leucemia Linfocítica Crónica de Células B , Linfoma de Células B Grandes Difuso , Humanos , Leucemia Linfocítica Crónica de Células B/genética , Hibridación Fluorescente in Situ , Translocación Genética , Reordenamiento Génico , Linfoma de Células B Grandes Difuso/genética , Cadenas Pesadas de Inmunoglobulina/genética , Cromosomas Humanos Par 14/genéticaRESUMEN
Key Clinical Message: HHV8- and EBV-negative primary effusion lymphoma is an extremely rare neoplasm involving body cavities without detectable tumor mass. It usually presents in elderly patients without known immunodeficiency. Compared to primary effusion lymphoma, it has a better prognosis.Primary effusion lymphoma (PEL) is a rare non-Hodgkin lymphoma confined exclusively to body cavities without detectable tumor masses. The term PEL-like is an entity similar to PEL in clinical presentation but without relation to human herpesvirus 8 (HHV8). We report a case of HHV8- and EBV-negative primary effusion-based lymphoma.
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Immune dysfunction in patients with multiple myeloma (MM) affects both the innate and adaptive immune system. Molecules involved in the immune checkpoint pathways are essential to determine the ability of cancer cells to escape from the immune system surveillance. However, few data are available concerning the role of these molecules in predicting the kinetics of progression of MM. We retrospectively analysed polymorphisms of CTLA4 (rs231775 and rs733618), BTLA (rs9288953), CD28 (rs3116496), PD-1 (rs36084323 and rs11568821) and LAG-3 (rs870849) genes in 239 patients with newly diagnosed MM. Patients with a CTLA4 rs231775 AA/AG genotype showed a median progression-free survival (PFS) significantly lower than those with GG genotype (32.3 months versus 96.8 months respectively; p: 0.008). The 5-year PFS rate was 25% for patients with grouped AA and AG genotype vs 55.4% for patients with GG genotype. Multivariate analysis confirmed the CTLA4 rs231775 genotype as an independent risk factor for PFS (Hazard Ratio (HR): 2.05; 95% CI: 1.0-6.2; p: 0.047). Our results suggest that the CTLA4 genotype may identify patients with earlier progression of MM. This polymorphism could potentially be used as a prognostic biomarker.
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Mieloma Múltiple , Humanos , Antígeno CTLA-4/genética , Mieloma Múltiple/genética , Estudios Retrospectivos , Polimorfismo de Nucleótido Simple , GenotipoRESUMEN
Chromosomal translocations in chronic lymphocytic leukemia (CLL) are very rare, and therefore systematic analysis of large series of cases is needed to allow the identification of recurrent rearrangements, breakpoints involved, and target genes. The aims of the present study were to identify new translocations and their clinical impact and to establish their frequency in a large cohort of 2843 CLL patients. By conventional cytogenetics 250 translocations were identified in 215 (7.5%) patients, 186 (74%) were apparently balanced and 64 (26%) were unbalanced. All chromosomes were involved in translocations, except Y chromosome. The chromosomes more frequently translocated were in decreasing frequency chromosomes 14, 18, 13, 17, 1, 6, 2, 3, 8, and 11. Translocations were found in the karyotypes either as the unique chromosomal abnormality (27%), associated with another alteration (24%), or as a part of a complex karyotype (CK, 48%). A large proportion of rearranged breakpoints involved genes related to CLL such as IGH (14q32), RB1, MIR15A, MIR16-1 (13q14), BCL2 (18q21), IGL (22q11.2), TP53 (17p13), IRF4 (6p25-p23), ATM (11q22), and CDK6 (7q21). Overall, 76 novel CLL translocations were identified, including a recurrent t(8;11)(p21;q21-23). Whole-genome sequencing and/or copy-number microarray data of 24 cases with translocations confirmed all rearrangements, enabled refinement of 3 karyotypes and all breakpoints at gene level. The projected survival and time to first treatment significantly decreased linearly with the number of translocations. In summary, this study allowed to establish the frequency of translocations (7.5%) and to identify new translocations in a cohort of 2843 CLL patients.
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Leucemia Linfocítica Crónica de Células B/genética , Translocación Genética/genética , Aberraciones Cromosómicas , Análisis Citogenético , Humanos , Cariotipo , Análisis de Secuencia por Matrices de Oligonucleótidos , Pronóstico , España , Secuenciación Completa del GenomaRESUMEN
The prognosis of t(1;19)(q23;p13)/transcription factor 3-pre-B-cell leukaemia homeobox 1 (TCF3-PBX1) in adolescent and adult patients with acute lymphoblastic leukaemia (ALL) treated with measurable residual disease (MRD)-oriented trials remains controversial. In the present study, we analysed the outcome of adolescent and adult patients with t(1;19)(q23;p13) enrolled in paediatric-inspired trials. The patients with TCF3-PBX1 showed similar MRD clearance and did not have different survival compared with other B-cell precursor ALL patients. However, patients with TCF3-PBX1 had a significantly higher cumulative incidence of relapse, especially among patients aged ≥35 years carrying additional cytogenetic alterations. These patients might benefit from additional/intensified therapy (e.g. immunotherapy in first complete remission with or without subsequent haematopoietic stem cell transplantation).
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Cromosomas Humanos Par 19 , Cromosomas Humanos Par 1 , Neoplasia Residual/terapia , Proteínas de Fusión Oncogénica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/terapia , Translocación Genética , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Bandeo Cromosómico , Manejo de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Estadificación de Neoplasias , Neoplasia Residual/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/mortalidad , Pronóstico , Inducción de Remisión , Resultado del Tratamiento , Adulto JovenRESUMEN
Somatic DNA hypomethylation and aneuploidy are hallmarks of cancer, and there is evidence for a causal relationship between them in knockout mice but not in human cancer. The non-mobile pericentromeric repetitive elements SST1 are hypomethylated in about 17% of human colorectal cancers (CRC) with some 5-7% exhibiting strong age-independent demethylation. We studied the frequency of genome doubling, a common event in solid tumors linked to aneuploidy, in randomly selected single cell clones of near-diploid LS174T human CRC cells differing in their level of SST1 demethylation. Near-diploid LS174T cells underwent frequent genome-doubling events generating near-tetraploid clones with lower levels of SST1 methylation. In primary CRC, strong SST1 hypomethylation was significantly associated with global genomic hypomethylation and mutations in TP53. This work uncovers the association of the naturally occurring demethylation of the SST1 pericentromeric repeat with the onset of spontaneous tetraploidization in human CRC cells in culture and with TP53 mutations in primary CRCs. Altogether, our findings provide further support for an oncogenic pathway linking somatic hypomethylation and genetic copy number alterations in a subset of human CRC.
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Haematopoietic malignancies are frequently characterized by karyotypic abnormalities. The development of targeted drugs has been pioneered with compounds against gene products of fusion genes caused by chromosomal translocations. While polysomies are equally frequent as translocations, for many of them we are lacking therapeutic approaches aimed at synthetic lethality. Here, we report two new cell lines, named MBU-7 and MBU-8, that differ in complete trisomy of chromosome18, a partial trisomy of chromosome 7 and a tetrasomy of the p-arm of chromosome 8, but otherwise share the same mutational pattern and complex karyotype. Both cell lines are divergent clones of U-937 cells and have the morphology and immunoprofile of monocytic cells. The distinct karyotypic differences between MBU-7 and MBU-8 are associated with a difference in the specific response to nucleoside analogues. Taken together, we propose the MBU-7 and MBU-8 cell lines described here as suitable in vitro models for screening and testing vulnerabilities that are associated with the disease-relevant polysomies of chromosome 7, 8 and 18.
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Biomarcadores de Tumor/genética , Cromosomas Humanos Par 18/genética , Cromosomas Humanos Par 7/genética , Cromosomas Humanos Par 8/genética , Leucemia Mieloide Aguda/genética , Línea Celular Tumoral , Humanos , Leucemia Mieloide Aguda/patología , Tetrasomía , TrisomíaRESUMEN
Despite high complete remission (CR) rates with frontline therapy, relapses are frequent in adults with T-cell acute lymphoblastic leukemia (T-ALL) with limited salvage options. We analyzed the outcomes and prognostic factors for CR to salvage therapy and overall survival (OS) of patients with R/R T-ALL included in two prospective measurable residual disease-oriented trials. Seventy-five patients (70 relapsed, 5 refractory) were identified. Relapses occurred in bone marrow, isolated or combined in 50 patients, and in the central nervous system (CNS; isolated or combined) in 20. Second CR was attained in 30/75 patients (40%). Treatment with FLAG-Ida and isolated CNS relapse were independently associated with a higher CR rate after first salvage therapy. The median OS was 6.2 (95% confidence interval [CI], 3.9-8.6) months, with a 4-year OS probability of 18% (95% CI, 9%-27%). No differences in survival were observed according to the treatment with hematopoietic stem cell transplantation in patients in CR after first salvage therapy. Multivariable analysis showed a ≥12-month interval between first CR and relapse, CR after first salvage therapy and isolated CNS relapse as favorable prognostic factors for OS with hazard ratios (HR) (95% CI) of 1.931 (1.109-3.362), 2.958 (1.640-5.334), and 2.976 (1.157-7.655), respectively. This study confirms the poor outcomes of adults with R/R T-ALL among whom FLAG-Ida was the best of the rescue therapies evaluated. Late relapse, CR after first rescue therapy and isolated CNS relapse showed prognostic impact on survival. More effective rescue therapies are needed in adults with R/R T-ALL.
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Leucemia-Linfoma Linfoblástico de Células T Precursoras/terapia , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasia Residual , Leucemia-Linfoma Linfoblástico de Células T Precursoras/mortalidad , Pronóstico , Resultado del Tratamiento , Adulto JovenRESUMEN
In myelodysplastic syndromes (MDS), the 20q deletion [del(20q)] may cause deletion of the ASXL1 gene. We studied 153 patients with MDS and del(20q) to assess the incidence, prognostic value and impact on response to azacitidine (AZA) of ASXL1 chromosomal alterations and genetic mutations. Additionally, in vitro assay of the response to AZA in HAP1 (HAP1WT ) and HAP1 ASXL1 knockout (HAP1KN ) cells was performed. ASXL1 chromosomal alterations were detected in 44 patients (28·5%): 34 patients (22%) with a gene deletion (ASXL1DEL ) and 10 patients (6·5%) with additional gene copies. ASXL1DEL was associated with a lower platelet count. The most frequently mutated genes were U2AF1 (16%), ASXL1 (14%), SF3B1 (11%), TP53 (7%) and SRSF2 (6%). ASXL1 alteration due to chromosomal deletion or genetic mutation (ASXL1DEL /ASXL1MUT ) was linked by multivariable analysis with shorter overall survival [hazard ratio, (HR) 1·84; 95% confidence interval, (CI): 1·11-3·04; P = 0·018] and a higher rate for acute myeloid leukaemia progression (HR 2·47; 95% CI: 1·07-5·70, P = 0·034). ASXL1DEL /ASXL1MUT patients were correlated by univariable analysis with a worse response to AZA. HAP1KN cells showed more resistance to AZA compared to HAP1WT cells. In conclusion, ASXL1 alteration exerts a negative impact on MDS with del(20q) and could become useful for prognostic risk stratification and treatment decisions.
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Antimetabolitos Antineoplásicos/uso terapéutico , Azacitidina/uso terapéutico , Deleción Cromosómica , Síndromes Mielodisplásicos/tratamiento farmacológico , Síndromes Mielodisplásicos/genética , Proteínas Represoras/genética , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Mutación , Síndromes Mielodisplásicos/diagnóstico , PronósticoRESUMEN
The potential prognostic value of conventional karyotyping in adult T-cell acute lymphoblastic leukemia (T-ALL) remains an open question. We hypothesized that a modified cytogenetic classification, based on the number and type of cytogenetic abnormalities, would allow the identification of high-risk adult T-ALL patients. Complex karyotype defined by the presence of ≥3 cytogenetic alterations identified T-ALL patients with poor prognosis in this study. Karyotypes with ≥3 abnormalities accounted for 16 % (22/139) of all evaluable karyotypes, corresponding to the largest poor prognosis cytogenetic subgroup of T-ALL identified so far. Patients carrying karyotypes with ≥3 cytogenetic alterations showed a significantly inferior response to therapy, and a poor outcome in terms of event-free survival (EFS), overall survival (OS) and cumulative incidence of relapse (CIR), independently of other baseline characteristics and the end-induction minimal residual disease (MRD) level. Additional molecular analyses of patients carrying ≥3 cytogenetic alterations showed a unique molecular profile that could contribute to understand the underlying molecular mechanisms of resistance and to evaluate novel targeted therapies (e.g. IL7R directed) with potential impact on outcome of adult T-ALL patients.
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Aberraciones Cromosómicas , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Adolescente , Adulto , Femenino , Humanos , Cariotipo , Masculino , Persona de Mediana Edad , Neoplasia Residual/diagnóstico , Neoplasia Residual/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/diagnóstico , Pronóstico , Adulto JovenRESUMEN
Extramedullary multiple myeloma (EMM) has an overall survival of 6â months and occurs in 20% of multiple myeloma (MM) patients. Genetic and epigenetic mechanisms involved in EMM and the therapeutic role of new agents for MM are not well established. Besides, well-characterized preclinical models for EMM are not available. Herein, a patient-derived orthotopic xenograft (PDOX) was generated from a patient with an aggressive EMM to study in-depth genetic and epigenetic events, and drug responses related to extramedullary disease. A fresh punch of an extramedullary cutaneous lesion was orthotopically implanted in NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ(NSG) mouse. The PDOX mimicked histologic and phenotypic features of the tumor of the patient. Cytogenetic studies revealed a hyperploid genome with multiple genetic poor-prognosis alterations. Copy number alterations (CNAs) were detected in all chromosomes. The IGH translocation t(14;16)(q32;q23)IGH/MAF was already observed at the medullary stage and a new one, t(10;14)(p?11-12;q32), was observed only with extramedullary disease and could be eventually related to EMM progression in this case. Exome sequencing showed 24 high impact single nucleotide variants and 180 indels. From the genes involved, only TP53 was previously described as a driver in MM. A rather balanced proportion of hyper/hypomethylated sites different to previously reported widespread hypomethylation in MM was also observed. Treatment with lenalidomide, dexamethasone and carfilzomib showed a tumor weight reduction of 90% versus non-treated tumors, whereas treatment with the anti-CD38 antibody daratumumab showed a reduction of 46%. The generation of PDOX from a small EMM biopsy allowed us to investigate in depth the molecular events associated with extramedullary disease in combination with drug testing.
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Mieloma Múltiple , Animales , Modelos Animales de Enfermedad , Xenoinjertos , Humanos , Ratones , Ratones Endogámicos NOD , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/genética , Mieloma Múltiple/patologíaRESUMEN
The alteration of RNA modification patterns is emerging as a common feature of human malignancies. If these changes affect key RNA molecules for mRNA translation, such as transfer RNA, they can have important consequences for cell transformation. TRIT1 is the enzyme responsible for the hypermodification of adenosine 37 in the anticodon region of human tRNAs containing serine and selenocysteine. Herein, we show that TRIT1 undergoes gene amplification-associated overexpression in cancer cell lines and primary samples of small-cell lung cancer. From growth and functional standpoints, the induced depletion of TRIT1 expression in amplified cells reduces their tumorigenic potential and downregulates the selenoprotein transcripts. We observed that TRIT1-amplified cells are sensitive to arsenic trioxide, a compound that regulates selenoproteins, whereas reduction of TRIT1 levels confers loss of sensitivity to the drug. Overall, our results indicate a role for TRIT1 as a small-cell lung cancer-relevant gene that, when undergoing gene amplification-associated activation, can be targeted with the differentiation agent arsenic trioxide.
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Myelodysplastic syndromes (MDS) are a heterogeneous group of hematological diseases. Among them, the most well characterized subtype is MDS with isolated chromosome 5q deletion (MDS del(5q)), which is the only one defined by a cytogenetic abnormality that makes these patients candidates to be treated with lenalidomide. During the last decade, single cell (SC) analysis has emerged as a powerful tool to decipher clonal architecture and to further understand cancer and other diseases at higher resolution level compared to bulk sequencing techniques. In this study, a SC approach was used to analyze intratumoral heterogeneity in four patients with MDS del(5q). Single CD34+CD117+CD45+CD19- bone marrow hematopoietic stem progenitor cells were isolated using the C1 system (Fluidigm) from diagnosis or before receiving any treatment and from available follow-up samples. Selected somatic alterations were further analyzed in SC by high-throughput qPCR (Biomark HD, Fluidigm) using specific TaqMan assays. A median of 175 cells per sample were analyzed. Inferred clonal architectures were relatively simple and either linear or branching. Similar to previous studies based on bulk sequencing to infer clonal architecture, we were able to observe that an ancestral event in one patient can appear as a secondary hit in another one, thus reflecting the high intratumoral heterogeneity in MDS del(5q) and the importance of patient-specific molecular characterization.
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Hypodiploidy with less than 40 chromosomes is a rare genetic abnormality in B-cell acute lymphoblastic leukemia (B-ALL). This condition can be classified based on modal chromosome number as low-hypodiploidy (30-39 chromosomes) and near-haploidy (24-29 chromosomes), with unique cytogenetic and mutational landscapes. Hypodiploid B-ALL with <40 chromosomes has an extremely poor outcome, with 5-year overall survival rates below 50% and 20% in childhood and adult B-ALL, respectively. Accordingly, this genetic feature represents an adverse prognostic factor in B-ALL and is associated with early relapse and therapy refractoriness. Notably, half of all patients with hypodiploid B-ALL with <40 chromosomes cases ultimately exhibit chromosome doubling of the hypodiploid clone, resulting in clones with 50-78 chromosomes. Doubled clones are often the major clones at diagnosis, leading to "masked hypodiploidy", which is clinically challenging as patients can be erroneously classified as hyperdiploid B-ALL. Here, we summarize the main cytogenetic and molecular features of hypodiploid B-ALL subtypes, and provide a brief overview of the diagnostic methods, standard-of-care treatments and overall clinical outcome. Finally, we discuss molecular mechanisms that may underlie the origin and leukemogenic impact of hypodiploidy and may open new therapeutic avenues to improve survival rates in these patients.
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The need for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in adults with Philadelphia chromosome-negative (Ph-) acute lymphoblastic leukemia (ALL) with high-risk (HR) features and adequate measurable residual disease (MRD) clearance remains unclear. The aim of the ALL-HR-11 trial was to evaluate the outcomes of HR Ph- adult ALL patients following chemotherapy or allo-HSCT administered based on end-induction and consolidation MRD levels. Patients aged 15 to 60 years with HR-ALL in complete response (CR) and MRD levels (centrally assessed by 8-color flow cytometry) <0.1% after induction and <0.01% after early consolidation were assigned to receive delayed consolidation and maintenance therapy up to 2 years in CR. The remaining patients were allocated to allo-HSCT. CR was attained in 315/348 patients (91%), with MRD <0.1% after induction in 220/289 patients (76%). By intention-to-treat, 218 patients were assigned to chemotherapy and 106 to allo-HSCT. The 5-year (±95% confidence interval) cumulative incidence of relapse (CIR), overall survival (OS), and event-free survival probabilities for the whole series were 43% ± 7%, 49% ± 7%, and 40% ± 6%, respectively, with CIR and OS rates of 45% ± 8% and 59% ± 9% for patients assigned to chemotherapy and of 40% ± 12% and 38% ± 11% for those assigned to allo-HSCT, respectively. Our results show that avoiding allo-HSCT does not hamper the outcomes of HR Ph- adult ALL patients up to 60 years with adequate MRD response after induction and consolidation. Better postremission alternative therapies are especially needed for patients with poor MRD clearance. This trial was registered at www.clinicaltrials.gov as # NCT01540812.