RESUMO
Distinguishing between follicular lymphoma (FL) and nodal marginal zone lymphoma (NMZL) can be difficult when morphologic and phenotypic features are unusual and characteristic cytogenetic rearrangements are absent. We evaluated the diagnostic contribution of ancillary techniques-including fluorescence in situ hybridization (FISH)-detected 1p36 deletion; reverse-transcriptase, multiplex, ligation-dependent probe amplification (RT-MLPA); and next-generation sequencing (NGS)-for tumors that remain unclassified according to standard criteria. After review, 50 CD5-negative small B-cell lymphoid neoplasms without BCL2 and BCL6 FISH rearrangements were diagnosed as FLs (n = 27), NMZLs (n = 5), or unclassified (n = 18) based on the 2016 World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues. FISH helped identify the 1p36 deletion in 3 FLs and 1 unclassified tumor. Most classified FLs had an RT-MLPA germinal center B-cell (GCB) signature (93%) or were noncontributive (7%). Classified NMZLs had an RT-MLPA activated B-cell signature (20%), had an unassigned signature (40%), or were noncontributive (40%). Among unclassified tumors, the RT-MLPA GCB signature was associated with mutations most commonly found in FLs (CREBBP, EZH2, STAT6, and/or TNFRSF14) (90%). An RT-MLPA-detected GCB signature and/or NGS-detected gene mutations were considered as FL identifiers for 13 tumors. An activated B-cell signature or NOTCH2 mutation supported NMZL diagnosis in 3 tumors. Combining the RT-MLPA and NGS findings successfully discriminated 89% of unclassified tumors in favor of one or the other diagnosis. NGS-detected mutations may be of therapeutic interest. Herein, we detected 3 EZH2 and 8 CREBBP mutations that might be eligible for targeted therapies.
Assuntos
Linfoma de Zona Marginal Tipo Células B , Linfoma Folicular , Humanos , Hibridização in Situ Fluorescente , Reação em Cadeia da Polimerase Multiplex , Linfoma de Zona Marginal Tipo Células B/genética , Linfoma Folicular/diagnóstico , Linfoma Folicular/genética , Sequenciamento de Nucleotídeos em Larga Escala , Deleção Cromossômica , RNA Polimerases Dirigidas por DNA , Proteínas Proto-Oncogênicas c-bcl-2 , Proteínas Proto-Oncogênicas c-bcl-6RESUMO
Sézary Syndrome (SS) is a rare aggressive epidermotropic cutaneous T-cell lymphoma (CTCL) defined by erythroderma, pruritis, and a circulating atypical CD4 + T-cell clonal population. The diversity of Sézary cell (SC) phenotype and genotype may reflect either plasticity or heterogeneity, which was difficult to evaluate dynamically until the achievement of long-term SC expansion. Therefore, we developed six defined culture conditions allowing for the expansion of SC defined by their phenotype and monoclonality in four of seven SS cases. Engraftment of SC through the intrafemoral route into immunodeficient NOD.Cg-Prkdc(scid)Il2rg(tm1Wjll)/SzJ (NSG) mice was achieved in 2 of 14 SS cases. Secondary xenograft by percutaneous injection mimicked most of the features of SS with dermal infiltration, epidermotropism, and blood spreading. These models also allowed assessing the intra-individual heterogeneity of patient SC. Subclones sharing the same TCR gene rearrangement evolved independently according to culture conditions and/or after xenografting. This clonal selection was associated with some immunophenotypic plasticity and limited genomic evolution both in vitro and in vivo. The long-term amplification of SC allowed us to develop eight new SC lines derived from four different patients. These lines represent the cell of origin diversity of SC and provide new tools to evaluate their functional hallmarks and response to therapy.
Assuntos
Células Clonais/patologia , Genes Codificadores dos Receptores de Linfócitos T , Síndrome de Sézary/patologia , Neoplasias Cutâneas/patologia , Adulto , Animais , Apoptose , Técnicas de Cultura de Células , Proliferação de Células , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Prognóstico , Síndrome de Sézary/genética , Neoplasias Cutâneas/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoAssuntos
Biomarcadores Tumorais/genética , Rearranjo Gênico , Genes myc , Hibridização in Situ Fluorescente/métodos , Linfoma Difuso de Grandes Células B/genética , Neoplasias Cutâneas/genética , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/patologia , Linfoma Difuso de Grandes Células B/terapia , Masculino , Pessoa de Meia-Idade , Prognóstico , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/terapiaRESUMO
Dasatinib is an ABL1 tyrosine kinase inhibitor (TKI) with a short in vivo plasmatic half-life but with good efficiency, which is not fully understood. We investigated the possibility that circulating erythrocytes store and then provide dasatinib to target cells. In vitro coincubation of dasatinib-treated cells with naïve leukemic cells followed by analysis of kinase inhibition, apoptosis induction, fluorescent molecule exchanges, and dasatinib dosage were performed. Cells incubated with clinically relevant concentrations of dasatinib for a short time retained, after a washout procedure, an intracellular pool of dasatinib which was transferable to naïve BCR-ABL1 expressing cells and induced their apoptosis. This was verified in total blood where the huge cellular volume of erythrocytes constituted a large reservoir of dasatinib able to induce apoptosis in naïve BCR-ABL1 cell lines and primitive chronic myeloid leukemia (CML) CD34+ cells. This dasatinib transfer necessitated a contact between donor and acceptor cells. A component exchange occurred during this contact, carrying dasatinib and other TKIs such as nilotinib or the fluorescent sunitinib. An active pool of dasatinib could be buried inside the circulating erythrocytes, out of reach of detoxifying mechanisms, but still available for target cells and thus extending the acute effect of the plasmatic pool of the drug.
RESUMO
Chronic lymphocytic leukemia (CLL) with 17p deletion (17p-) is associated with a lack of response to standard treatment and thus the worst possible clinical outcome. Various chromosomal abnormalities (including unbalanced translocations, deletions, ring chromosomes and isochromosomes) result in the loss of 17p and one copy of the TP53 gene. The objective of the present study was to determine whether the type of chromosomal abnormality leading to 17p- and the additional aberrations influenced the prognosis in a series of 195 patients with 17p-CLL. Loss of 17p resulted primarily from an unbalanced translocation (70%) with several chromosome partners (the most frequent being chromosome 18q), followed by deletion 17p (23%), monosomy 17 (8%), isochromosome 17q [i(17q)] (5%) and a ring chromosome 17 (2%). In a univariate analysis, monosomy 17, a highly complex karyotype (≥5 abnormalities), and 8q24 gain were associated with poor treatment-free survival, and i(17q) (P = .04), unbalanced translocations (P = .03) and 8q24 gain (P = .001) were significantly associated with poor overall survival. In a multivariate analysis, 8q24 gain remained a significant predictor of poor overall survival. We conclude that 17p deletion and 8q24 gain have a synergistic impact on outcome, and so patients with this "double-hit" CLL have a particularly poor prognosis. Systematic, targeting screening for 8q24 gain should therefore be considered in cases of 17p- CLL.
Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 17/ultraestrutura , Cromossomos Humanos Par 8/ultraestrutura , Leucemia Linfocítica Crônica de Células B/genética , Translocação Genética , Trissomia , Cariótipo Anormal , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Feminino , Genes p53 , Humanos , Hibridização in Situ Fluorescente , Estimativa de Kaplan-Meier , Leucemia Linfocítica Crônica de Células B/mortalidade , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Prognóstico , Estudos RetrospectivosRESUMO
Recent massive parallel sequencing data have evidenced the genetic diversity and complexity of Sézary syndrome mutational landscape with TP53 alterations being the most prevalent genetic abnormality. We analyzed a cohort of 35 patients with SS and a control group of 8 patients with chronic inflammatory dermatoses. TP53 status was analyzed at different clinical stages especially in 9 patients with a past-history of mycosis fungoides (MF), coined secondary SS. TP53 mutations were only detected in 10 patients with either primary or secondary SS (29%) corresponding to point mutations, small insertions and deletions which were unique in each case. Interestingly, TP53 mutations were both detected in sequential unselected blood mononuclear cells and in skin specimens. Cytogenetic analysis of blood specimens of 32 patients with SS showed a TP53 deletion in 27 cases (84%). Altogether 29 out of 35 cases exhibited TP53 mutation and/or deletion (83%). No difference in prognosis was observed according to TP53 status while patients with secondary SS had a worse prognosis than patients with primary SS. Interestingly, patients with TP53 alterations displayed a younger age and the presence of TP53 alteration at initial diagnosis stage supports a pivotal oncogenic role for TP53 mutation in SS as well as in erythrodermic MF making TP53 assessment an ancillary method for the diagnosis of patients with erythroderma as patients with inflammatory dermatoses did not display TP53 alteration.
Assuntos
Dermatite Esfoliativa/complicações , Genes p53 , Síndrome de Sézary/genética , Neoplasias Cutâneas/genética , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Variações do Número de Cópias de DNA , Feminino , Citometria de Fluxo , Humanos , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Síndrome de Sézary/complicações , Neoplasias Cutâneas/complicaçõesRESUMO
Monoallelic 6p25.3 rearrangements associated with DUSP22 (Dual Specificity Phosphatase 22) gene silencing have been reported in CD30+ peripheral T-cell lymphomas (PTCL), mostly with anaplastic morphology and of cutaneous origin. However, the mechanism of second allele silencing and the putative tumor suppressor function of DUSP22 have not been investigated so far. Here, we show that the presence, in most individuals, of an inactive paralog hampers genetic and epigenetic evaluation of the DUSP22 gene. Identification of DUSP22-specific single-nucleotide polymorphisms haplotypes and fluorescence in situ hybridization and epigenetic characterization of the paralog status led us to develop a comprehensive strategy enabling reliable identification of DUSP22 alterations. We showed that one cutaneous anaplastic large T-cell lymphomas (cALCL) case with monoallelic 6p25.3 rearrangement and DUSP22 silencing harbored exon 1 somatic mutations associated with second allele inactivation. Another cALCL case carried an intron 1 somatic splice site mutation with predicted deleterious exon skipping effect. Other tested PTCL cases with 6p25.3 rearrangement exhibited neither mutation nor deletion nor methylation accounting for silencing of the non-rearranged DUSP22 allele, thus inactivated by a so far unknown mechanism. We also characterized the expression status of four DUSP22 splice variants and found that they are all silenced in cALCL cases with 6p25.3 breakpoints. We finally showed that restoring expression of the physiologically predominant isoform in DUSP22-deficient malignant T cells inhibits cellular expansion by stimulating apoptosis and impairs soft agar clonogenicity and tumorigenicity. This study therefore shows that DUSP22 behaves as a tumor suppressor gene in PTCL.
Assuntos
Fosfatases de Especificidade Dupla/genética , Linfoma de Células T/genética , Fosfatases da Proteína Quinase Ativada por Mitógeno/genética , Polimorfismo de Nucleotídeo Único , Proteínas Supressoras de Tumor/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Processamento Alternativo , Sequência de Aminoácidos , Sequência de Bases , Cromossomos Humanos Par 6/genética , Metilação de DNA , Fosfatases de Especificidade Dupla/metabolismo , Feminino , Rearranjo Gênico , Humanos , Hibridização in Situ Fluorescente , Linfoma Anaplásico de Células Grandes/enzimologia , Linfoma Anaplásico de Células Grandes/genética , Linfoma de Células T/metabolismo , Linfoma Cutâneo de Células T/enzimologia , Linfoma Cutâneo de Células T/genética , Linfoma de Células T Periférico/embriologia , Linfoma de Células T Periférico/genética , Masculino , Pessoa de Meia-Idade , Fosfatases da Proteína Quinase Ativada por Mitógeno/metabolismo , Mutação , Proteínas Supressoras de Tumor/metabolismoRESUMO
Importance: The differential diagnosis between proliferative nodules (PNs) and melanoma arising in congenital melanocytic nevi (CMN) is crucial, as patients with PNs most often experience no increased risk of melanoma with metastases and death. Objective: To analyze the utility of immunohistochemistry and fluorescence in situ hybridization (FISH) in distinguishing PNs from childhood and adult-onset melanoma arising in CMN. Design, Setting, and Participants: A case series was conducted from June 29, 1989, to November 12, 2009, of 13 children with PNs arising in CMN in childhood and 5 children with melanomas arising in CMN in childhood. Five patients with giant CMN with no nodules were included as negative controls, and 6 patients with melanomas arising in CMN in adulthood were included as positive controls. Follow-up ranged from 3 to 21 years in all children (mean, 9.9 years) and from 3 months to 7 years in adults. Specimens were selected for immunohistochemistry and FISH. All histopathologic sections were reviewed by 2 dermatopathologists who examined all nodules arising at different ages in the same patient and, in the case of melanoma, all locations. Data analysis was performed from January 1, 2013, to January 31, 2015. Main Outcomes and Measures: The ability to distinguish melanoma from PN using immunohistochemistry and/or FISH. Results: Of the 13 patients (5 boys and 8 girls) with PNs present at birth, all PNs were stable (mean follow-up, 9 years). Eight patients with PNs and 4 of 5 patients with childhood-onset melanoma showed homogeneous staining for HMB45, while heterogeneous staining for HMB45 was seen in 3 of 6 patients with adult-onset melanoma. Expression of p16 was strongly positive in most patients with childhood-onset PNs (10 of 11 patients) and melanoma (all patients) but negative in 4 patients with adult-onset melanoma. Patients with PNs and the 5 patients with childhood-onset melanoma had numerical chromosomal aberrations never observed in the adjacent CMN. The 2 children with FISH-positive PNs are melanoma free after 7 and 4 years. Only 1 patient with childhood-onset melanoma had a FISH aberration compared with 4 patients with adult-onset melanoma. Conclusions and Relevance: Immunohistochemistry and the 4-probe FISH melanoma analysis are not useful for distinguishing PN from childhood-onset melanoma as opposed to adult-onset melanoma. Numerical anomalies seen in PNs but not in the adjacent CMN could be the result of a chromosomal segregation malfunction resulting in the development of nodules.
Assuntos
Biomarcadores Tumorais/metabolismo , Proliferação de Células , Melanoma/patologia , Nevo Pigmentado/patologia , Neoplasias Cutâneas/patologia , Adulto , Transformação Celular Neoplásica , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Seguimentos , França , Humanos , Imuno-Histoquímica/métodos , Hibridização in Situ Fluorescente/métodos , Masculino , Sistemas Computadorizados de Registros Médicos , Melanoma/metabolismo , Melanoma/mortalidade , Nevo Intradérmico/patologia , Nevo Pigmentado/metabolismo , Estudos Retrospectivos , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/mortalidadeRESUMO
T cell acute lymphoblastic leukemia (T-ALL) develops through accumulation of multiple genomic alterations within T-cell progenitors resulting in clonal heterogeneity among leukemic cells. Human T-ALL xeno-transplantation in immunodeficient mice is a gold standard approach to study leukemia biology and we recently uncovered that the leukemia development is more or less rapid depending on T-ALL sample. The resulting human leukemia may arise through genetic selection and we previously showed that human T-ALL development in immune-deficient mice is significantly enhanced upon CD7+/CD34+ leukemic cell transplantations. Here we investigated the genetic characteristics of CD7+/CD34+ and CD7+/CD34- cells from newly diagnosed human T-ALL and correlated it to the speed of leukemia development. We observed that CD7+/CD34+ or CD7+/CD34- T-ALL cells that promote leukemia within a short-time period are genetically similar, as well as xenograft-derived leukemia resulting from both cell fractions. In the case of delayed T-ALL growth CD7+/CD34+ or CD7+/CD34- cells were either genetically diverse, the resulting xenograft leukemia arising from different but branched subclones present in the original sample, or similar, indicating decreased fitness to mouse micro-environment. Altogether, our work provides new information relating the speed of leukemia development in xenografts to the genetic diversity of T-ALL cell compartments.
Assuntos
Variação Genética , Transplante de Neoplasias , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Transplante Heterólogo , Animais , Antígenos CD34/metabolismo , Linhagem Celular Tumoral , Criança , Progressão da Doença , Heterogeneidade Genética , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID , Camundongos Transgênicos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Fatores de Tempo , Adulto JovemRESUMO
A 63-year-old caucasian woman, presenting with metastatic primitive lung adenocarcinoma was treated with ALK inhibitor crizotinib treatment for six month. After rapid regression of all known lesions, tumor progression appeared six month later on all the already known lesions. A biopsy of subclavicular lymphadenopathy revealed a carcinoma with neuroendocrine phenotype with both immunohistochemical expression of ALK protein and ALK-rearrangement. It was associated with acquired resistance to crizotinib with ALK-rearrangement but without point mutation or amplification of the ALK gene. We herein report the first case of histological neuroendocrine transformation after ALK inhibitor crizotinib treatment, associated with acquired resistance to crizotinib.
Assuntos
Adenocarcinoma/enzimologia , Adenocarcinoma/patologia , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/patologia , Tumores Neuroendócrinos/patologia , Receptores Proteína Tirosina Quinases/genética , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Adenocarcinoma de Pulmão , Quinase do Linfoma Anaplásico , Clavícula/patologia , Crizotinibe , Resistencia a Medicamentos Antineoplásicos , Feminino , Rearranjo Gênico , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Pessoa de Meia-Idade , Inibidores de Proteínas Quinases/uso terapêutico , Pirazóis/uso terapêutico , Piridinas/uso terapêutico , Receptores Proteína Tirosina Quinases/metabolismoAssuntos
Linfoma Cutâneo de Células T/genética , Mutação , Fosfolipase C gama/genética , Neoplasias Cutâneas/genética , Biópsia por Agulha , Análise Mutacional de DNA , Humanos , Linfoma Cutâneo de Células T/patologia , Estudos de Amostragem , Sensibilidade e Especificidade , Neoplasias Cutâneas/patologiaRESUMO
OBJECTIVES: To study the diagnostic value of BCL2 rearrangement in follicle center lymphoma (FCL) presenting as primary skin lesions, evaluate its prevalence and the prognostic value in primary cutaneous FCL (PCFCL), and assess prognostic factors in PCFCL. METHODS: Fifty-three patients with a cutaneous presentation of FCL without a history of nodal lymphoma were selected retrospectively. Clinical and histologic data were collected together with staging and follow-up data. A fluorescence in situ hybridization (FISH) test for BCL2 split probes was performed on skin biopsy specimens. RESULTS: Initial staging procedures identified 47 PCFCLs and six cases of secondary skin involvement of FCL (SSIFCL). FISH detected seven cases carrying a BCL2 rearrangement: four (8.5%) of 47 PCFCLs and three (50%) of six SSIFCLs. These seven cases coexpressed BCL2 and CD10. In PCFCL, cutaneous relapse rate was 42.6%. A small/medium centrocytic cell population was associated with a higher probability of skin relapse in univariate (P = .008) and multivariate (P = .028) analysis, and BCL2 rearrangement detection was associated with secondary extracutaneous spreading (P = .05). CONCLUSIONS: We observed that BCL2 rearrangement in PCFCL is rare, associated with initial positivity of staging (diagnostic value) or with secondary extracutaneous spreading (prognostic value). In selected cases with BCL2-CD10 coexpression, FISH testing could detect patients with poor outcome and require closer monitoring.
Assuntos
Rearranjo Gênico , Linfoma Folicular/genética , Recidiva Local de Neoplasia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Neoplasias Cutâneas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , DNA de Neoplasias/genética , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Hibridização in Situ Fluorescente , Linfoma Folicular/patologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prognóstico , Recidiva , Estudos Retrospectivos , Pele/patologia , Neoplasias Cutâneas/patologiaRESUMO
Telomere erosion may be counteracted by telomerase. Here we explored telomere length (TL) and telomerase activity (TA) in primary cutaneous T-cell lymphoma (CTCL) by using quantitative polymerase chain reaction and interphase quantitative fluorescence in situ hybridization assays. Samples from patients with Sézary syndrome (SS), transformed mycosis fungoides (T-MF), and cutaneous anaplastic large cell lymphoma were studied in parallel with corresponding cell lines to evaluate the relevance of TL and TA as target candidates for diagnostic and therapeutic purposes. Compared with controls, short telomeres were observed in aggressive CTCL subtypes such as SS and T-MF and were restricted to neoplastic cells in SS. While no genomic alteration of the hTERT (human telomerase catalytic subunit) locus was observed in patients' tumor cells, TA was detected. To understand the role of telomerase in CTCL, we manipulated its expression in CTCL cell lines. Telomerase inhibition rapidly impeded in vitro cell proliferation and led to cell death, while telomerase overexpression stimulated in vitro proliferation and clonogenicity properties and favored tumor development in immunodeficient mice. Our data indicate that, besides maintenance of TL, telomerase exerts additional functions in CTCL. Therefore, targeting these functions might represent an attractive therapeutic strategy, especially in aggressive CTCL.
Assuntos
Linfoma Cutâneo de Células T/enzimologia , Neoplasias Cutâneas/enzimologia , Telomerase/fisiologia , Homeostase do Telômero/fisiologia , Animais , Estudos de Casos e Controles , Morte Celular , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Xenoenxertos , Humanos , Linfoma Anaplásico de Células Grandes/enzimologia , Linfoma Anaplásico de Células Grandes/genética , Linfoma Cutâneo de Células T/genética , Linfoma Cutâneo de Células T/patologia , Masculino , Camundongos , Camundongos SCID , Micose Fungoide/enzimologia , Micose Fungoide/genética , Transplante de Neoplasias , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Síndrome de Sézary/enzimologia , Síndrome de Sézary/genética , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Telomerase/antagonistas & inibidores , Telomerase/genética , Homeostase do Telômero/genéticaRESUMO
Metanephric stromal tumor is a rare benign entity belonging to the group of metanephric renal tumors in children. Although metanephric stromal tumors can be cured by simple nephrectomy, differential diagnosis based on histopathologic criteria with other pediatric renal tumors requiring aggressive chemotherapy can be difficult. To our knowledge, cytogenetic characterization of metanephric stromal tumor has never been reported. We describe conventional ("R-bands" karyotyping) and molecular [fluorescence in situ hybridization (FISH), multicolor FISH, oligo array-comparative genomic hybridization] cytogenetic examinations of a metanephric stromal tumor in a 3-year-old boy. Cytogenetic analysis revealed a complex homogeneous gain between bands 17q22 and 17q25.3, resulting in partial triplication of the segment between bands 17q22 and 17q24.3, and duplication of the segment between bands 17q24.3 and 17q25.3. Cytogenetic confirmatory studies in metanephric stromal tumors are currently needed to assess 17q22q25.3 gain as a recurring cytogenetic abnormality of metanephric stromal tumors.
Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 17 , Rearranjo Gênico , Neoplasias Renais/genética , Biópsia por Agulha , Pré-Escolar , Humanos , Cariotipagem , Neoplasias Renais/patologia , MasculinoRESUMO
Gliomas are the most common malignant primary brain tumors in adults. The median survival never exceeds 12 months, owing to inherent resistance to both radio and chemotherapies. Epidermal Growth Factor Receptor (EGFR) is amplified, overexpressed, and/or mutated in glioblastomas (GBM), making it a rational for therapy. Erlotinib, an EGFR kinase inhibitor is strongly associated with clinical response in several cancers. Inhibition of cell proliferation and induction of apoptosis by erlotinib were investigated in U87-MG and DBTRG-05MG, two human glioblastoma cell lines. The expression of several apoptosis-related proteins was investigated in these cell lines and in tumoral tissue from glioblastomas. Both cell lines expressed wild-type EGFR but were deficient for PTEN. Erlotinib induced a marked accumulation of the BIM protein, but the activation of caspase-3 machinery was missing, regardless of the decrease in XIAP. Moreover, in U87-MG, erlotinib promoted accumulation of αB-crystallin a small heat shock protein capable to impair caspase activation. DBTRG-05MG was found deficient for procaspase 3 and constitutively overexpressed αB-crystallin. Similarly, deficiencies in PTEN and procaspase 3 were constantly found in samples from glioblastoma samples, while αB-crystallin expression was inconsistent. In cell lines, high concentrations of erlotinib induced cell death through a caspase independent process and an autophagic process was evidenced in U87-MG. Inhibition of autophagy induced a marked increase in the death-inducing activity of erlotinib. These results confirm that glioblastoma cell lines exhibit several anti-apoptotic mechanisms, and underline that EGFR targeted therapy must be associated to other inhibitors to achieve an antitumoral effect.
Assuntos
Antineoplásicos/farmacologia , Autofagia/efeitos dos fármacos , Glioblastoma/patologia , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Proteína 11 Semelhante a Bcl-2 , Caspases/metabolismo , Linhagem Celular Tumoral , Receptores ErbB/antagonistas & inibidores , Cloridrato de Erlotinib , Glioblastoma/ultraestrutura , Células HeLa , Humanos , Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
This study was undertaken to identify recurrent genetic alterations of the three main types of cutaneous T-cell lymphomas (CTCLs): mycosis fungoides (MF), Sézary syndrome (SS), and cutaneous anaplastic large-cell lymphoma (CALCL). Using array-based comparative genomic hybridization, the molecular cytogenetic profiles of 72 samples obtained from 58 patients with CTCL corresponding to 24 transformed MF (T-MF), 16 SS, and 18 CALCLs were determined. T-MF was characterized by gains of 1q25-31, 7p22-11.2, 7q21, 7q31, and 17q12, and losses of 9p21, 10p11.2, and 10q26. SS exhibited gains of 8q23-24.3 and 17q23-24, as well as losses of 9p21, 10p12-11.2, 10q22-24, 10q25-26, and 17p13-q11.1. Finally, CALCL exhibited 6q27 and 13q34 losses. Such imbalances were statistically associated with one CTCL subtype. Unsupervised hierarchical clustering defined three categories of clinical relevance: (1) CALCL apart from epidermotropic-CTCL, (2) an SS-only category, and (3) a mixed category with T-MF and SS cases, with both primary and secondary SS cases. In rare cases, the genetic classification did not correspond to the inclusion diagnosis, possibly reflecting the association of two diseases in the same patient or initial misdiagnosis according to follow-up. Finally, different samples in the same patient clustered together, showing reproducibility of such a classifier.