RESUMO
Flavopiridol, an inhibitor of cyclin-dependent kinases and other protein kinases, induces in vitro apoptosis of malignant cells from B-cell chronic lymphocytic leukemia (B-CLL). Previously, we reported that nitric oxide (NO), produced by an inducible NO synthase (iNOS), spontaneously expressed by the B-CLL cells, contributed to their deficiency in apoptosis. In the present work, we show that ex vivo treatment of leukemic cells from B-CLL patients with flavopiridol results in the inhibition of iNOS expression, as determined by immunofluorescence and Western blotting, and in a marked inhibition of NO production measured in situ with a specific fluorescent probe (DAF-2 DA). These effects are accompanied by membrane, mitochondrial and nuclear events of apoptosis. Flavopiridol exposure also results in the stimulation of caspase 3 activity and in caspase-dependent cleavage of p27(kip1), a negative regulator of the cell cycle, which is overexpressed in B-CLL. Thus, flavopiridol is capable of downregulating both iNOS and p27(kip1) expression in B-CLL cells. Furthermore, flavopiridol-promoted apoptosis is partly reverted by an NO donor, suggesting that inhibition of the NO pathway could participate in the apoptotic effects of flavopiridol on the leukemic cells.
Assuntos
Antineoplásicos/farmacologia , Proteínas de Ciclo Celular/metabolismo , Flavonoides/farmacologia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/metabolismo , Óxido Nítrico Sintase/metabolismo , Piperidinas/farmacologia , Proteínas Supressoras de Tumor/metabolismo , Idoso , Apoptose/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p27 , Regulação para Baixo/efeitos dos fármacos , Feminino , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/metabolismo , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase Tipo IIRESUMO
Characteristics of treatment-induced cell cycle arrest are important for in vitro and in vivo sensitivity of acute myeloid leukemia (AML) cells to cytotoxic drugs. We analyzed the expression of the major G1 cell cycle regulators (p21Cip1, p27Kip1, cyclins D, cyclin E and pRb) in 41 fresh AML cell samples. The level of p27 expression was the only factor correlated with the response to chemotherapy, a high level of p27 expression being predictive of complete remission. There was a close relation between expression of pRb, cyclin D2 and FAB subtype, illustrated by the absence of both proteins in most samples having a monocytic component (M4, M5). We also assessed the expressions of pRb, cyclin E, p21 and p27 and the activity of cdk2, the major regulator of S-phase entry, after exposure to cytosine-arabinoside (AraC) and daunorubicin (DNR), and found these proteins could characterize time- and dose-dependent cellular response to each drug. We observed hyperphosphorylated pRb, increased levels of cyclin E and a high cdk2 activity, but no p21 induction, in AML cells exposed to 10(-6) M AraC. After exposure to 10(-5) M AraC, corresponding to the serum concentration reached in high-dose AraC regimens (HDAraC), a strong p21 induction was observed, associated with similarly overexpressed cyclin E and even higher cdk2 activity than after 10(-6) M AraC, while apoptosis was significantly increased. These data suggest that cdk2 activity is likely to play a role in AraC-induced apoptosis in AML cells. This mechanism may account for high efficacy of HDAraC in cells showing little sensitivity to conventional AraC doses.
Assuntos
Quinases relacionadas a CDC2 e CDC28 , Proteínas de Ciclo Celular , Ciclina E/análise , Ciclinas/análise , Leucemia Mieloide Aguda/metabolismo , Proteínas Associadas aos Microtúbulos/análise , Proteína do Retinoblastoma/análise , Proteínas Supressoras de Tumor , Apoptose , Ciclina D , Quinase 2 Dependente de Ciclina , Inibidor de Quinase Dependente de Ciclina p21 , Inibidor de Quinase Dependente de Ciclina p27 , Quinases Ciclina-Dependentes/análise , Citarabina/farmacologia , Dano ao DNA , Daunorrubicina/farmacologia , Humanos , Interleucina-3/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/patologia , Proteínas Serina-Treonina Quinases/análise , Fator de Células-Tronco/farmacologiaRESUMO
Steel factor (SF) synergizes with a variety of hemopoietins to support the growth and differentiation of human progenitor cells. The human factor-dependent cell line MO7 has been used as a model to study the interaction of SF with other growth factors such as GM-CSF, because both factors support the proliferation of this cell line and are synergistic in combination. Previous studies have shown that this effect is not readily explained by the synergistic activation of early, cytosolic signal transduction intermediates such as tyrosine kinases, Raf-1, MAP2 kinase, or phospholipase C gamma. In an attempt to further explore the biological and biochemical mechanisms of the synergy between SF and GM-CSF, we examined the effects of these growth factors on the regulation of nuclear proto-oncogenes, cell cycle control genes, and G1-->S transition of MO7 cells. Individually, GM-CSF was a much more potent growth factor for MO7 cells than SF, particularly under serum-free conditions. Only GM-CSF, but not SF, was able to stimulate G1-->S transition of MO7 cells after factor deprivation for 24 h. Northern blot analyses showed also differential effects of GM-CSF and SF on the expression of some nuclear proto-oncogenes and G1 cyclins. GM-CSF (10 ng/ml), but not SF (20 ng/ml) increased the expression of c-myc and cyclin D2 mRNA, whereas both factors caused transient increases of c-fos and cyclin D3 mRNAs. When added simultaneously, GM-CSF and SF induced an at least additive increase of c-fos mRNA expression; this effect required the presence of fetal calf serum. No additive effects of GM-CSF and SF on c-myc, cyclin D2 or D3 mRNA expression were observed. C-jun and c-myb mRNAs were constitutively expressed in the MO7 cell line, but not further increased after stimulation with GM-CSF or SF for 15 min to 48 h. The inability of SF to induce growth promoting genes such as c-myc and cyclin D2 may explain why this cytokine does not support sustained proliferation of MO7 cells. These observations suggest that SF and GM-CSF exert different effects on the expression of genes involved in regulatory pathways of cell proliferation, but the molecular mechanism of synergy remains to be elucidated.
Assuntos
Ciclinas/genética , Regulação Leucêmica da Expressão Gênica , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Fatores de Crescimento de Células Hematopoéticas/metabolismo , Leucemia Megacarioblástica Aguda/genética , Transdução de Sinais , Fatores de Transcrição/genética , Divisão Celular , Sinergismo Farmacológico , Fase G1 , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Fatores de Crescimento de Células Hematopoéticas/genética , Fatores de Crescimento de Células Hematopoéticas/farmacologia , Humanos , Leucemia Megacarioblástica Aguda/metabolismo , Leucemia Megacarioblástica Aguda/patologia , Proto-Oncogenes/genética , Fase S , Fator de Células-Tronco , Células Tumorais Cultivadas/metabolismo , Células Tumorais Cultivadas/patologiaRESUMO
B-cell chronic lymphocytic leukemia (B-CLL) is characterized by the accumulation of growth arrested clonal B lymphocytes that undergo apoptosis when treated with fludarabine. To further explore the mechanism for the cell cycle arrest, we examined the expression and activity of cyclin-dependent kinases and inhibitors in primary B-CLL cells. We observed high levels of p27kip1, cyclin D2, cyclin E, cdk2, and cdk4 expression in freshly isolated B-CLL cells. Despite high levels of cyclins and cdks, little cdk2 or cdk4 activity was observed with p27kip1 in complex with cyclinD2/cdk4 and cyclin E/cdk2. Remarkably, when B-CLL cells were treated in vitro with fludarabine, p27kip1 underwent caspase-specific degradation accompanied by an increase in cdk4 activity. We conclude that the G0/G1 arrest of B-CLL cells may protect against apoptosis and that the decrease in p27kip1 expression by caspase cleavage may be a key step in chemotherapy-induced apoptosis in B-CLL.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Quinases relacionadas a CDC2 e CDC28 , Caspases/metabolismo , Proteínas de Ciclo Celular/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Proteínas Proto-Oncogênicas , Proteínas Supressoras de Tumor/metabolismo , Vidarabina/análogos & derivados , Vidarabina/farmacologia , Western Blotting , Inibidores de Caspase , Ciclo Celular/efeitos dos fármacos , Ciclina D2 , Ciclina E/metabolismo , Quinase 2 Dependente de Ciclina , Quinase 4 Dependente de Ciclina , Inibidor de Quinase Dependente de Ciclina p27 , Quinases Ciclina-Dependentes/metabolismo , Ciclinas/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , Marcação In Situ das Extremidades Cortadas , Leucemia Linfocítica Crônica de Células B/enzimologia , Testes de Precipitina , Proteínas Serina-Treonina Quinases/metabolismo , Frações Subcelulares , Células Tumorais CultivadasRESUMO
Nodal mantle cell lymphoma (MCL) is a well-defined entity, but non-nodal leukemic cyclin D1 positive lymphoproliferative disorders have been reported and their relationship with MCL remains controversial and their prognosis heterogeneous. We prospectively studied the expression of cyclin D1 in CD5 positive leukemic B lymphoproliferative disorders at diagnosis and identified 65 cases overexpressing cyclin D1. We did not distinguish any clinical or biological criteria allowing one to identify a non-MCL group. Multivariate analysis identified age, anemia and p27kip1 expression as independent prognostic factors of survival. By univariate analysis, p27kip1 high expression proved to be the strongest predictor of prolonged survival. The median survival of p27 low expressors was 30 months, while it was not reached for p27 high expressors. A high level of p27 expression was often found associated with the absence of nodal involvement and the presence of somatic mutations, but neither of them was restricted to the p27 high expression group. In conclusion, we hypothesize that MCL and these cyclin D1 positive leukemic lymphoproliferative disorders represent a continuous spectrum of diseases. Determination of p27 expression level appears as a routine applicable test allowing identification of a subset of patients who could be considered for different therapeutic approaches.
Assuntos
Proteínas de Ciclo Celular/análise , Ciclina D1/análise , Transtornos Linfoproliferativos/metabolismo , Proteínas Supressoras de Tumor/análise , Adulto , Idoso , Aberrações Cromossômicas , Inibidor de Quinase Dependente de Ciclina p27 , Feminino , Genes de Imunoglobulinas , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Imunofenotipagem , Transtornos Linfoproliferativos/genética , Transtornos Linfoproliferativos/imunologia , Masculino , Pessoa de Meia-Idade , PrognósticoRESUMO
Recent work suggests that chronic lymphocytic leukemia (B-CLL) expressing unmutated immunoglobulin V genes could correspond to the proliferation of naive B cells whereas those expressing mutated genes, may correspond to the proliferation of post-germinal center B cells. Current data from gene profiling expression have failed to demonstrate a clear-cut distinction between these two forms of B-CLL disease. In the present study, we have investigated the complete V(H) nucleotide sequence and the presence of RNA transcripts from different C(H) domains in 25 B-CLL patients. Our results demonstrate that: (1) expression of IgD is not related to the mutational frequency and activation of the isotype switch pathway; (2) isotype switch, leading to simultaneous expression at the transcriptional and protein level of IgM, IgD, IgG and IgA, occurs in a small percentage of patients, and (3) different mechanisms such as VDJ duplication and trans-splicing or RNA splicing of long nuclear transcript, could be involved in isotype switch. Our results highlight the difficulty in assigning a normal counterpart to B-CLL cells and raise the possibility that a different B cell development pathway, independent from classical germinal centers, might exist in B-CLL.
Assuntos
Linfócitos B/imunologia , Genes de Imunoglobulinas/genética , Switching de Imunoglobulina/genética , Memória Imunológica , Leucemia Linfocítica Crônica de Células B/imunologia , Mutação , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Aminoácidos , Feminino , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Isotipos de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Leucemia Linfocítica Crônica de Células B/genética , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Fenótipo , RNA Mensageiro/análiseRESUMO
In B-CLL IgV(H) genes mutational status is a major prognostic factor. Since sequencing of IgV(H) genes is not available in most laboratories, an easily performed surrogate assay is desirable. To identify the best surrogate assay, and to better discriminate prognostic subgroups we analyzed clinical and biological data from 58 typical CLL cases. A higher serum thymidine kinase level (>15 U/l) proved to be a strong predictor of mutational status, and the only independent one among the studied parameters. To further identify prognostic subgroups, cluster analysis was employed on 38 cases on which all data were available, which segregated two groups including 25 and 13 patients, respectively. These two clusters differed by their proliferative potential and appeared to discriminate patients with very different clinical course and outcome. s-TK was strikingly different among these two clusters, suggesting that s-TK level could be used routinely to identify patients at risk of progression.
Assuntos
Linfócitos B/imunologia , Biomarcadores Tumorais , Genes de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/imunologia , Mutação , Timidina Quinase/sangue , Idoso , Antígenos CD/imunologia , Proteínas de Ciclo Celular/metabolismo , Ciclina D2 , Inibidor de Quinase Dependente de Ciclina p27 , Ciclinas/metabolismo , Progressão da Doença , Feminino , Humanos , Imunofenotipagem , L-Lactato Desidrogenase/metabolismo , Leucemia Linfocítica Crônica de Células B/diagnóstico , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Prognóstico , Taxa de Sobrevida , Proteínas Supressoras de Tumor/metabolismo , Microglobulina beta-2/metabolismoRESUMO
The conjunction of clinical features, cell morphology and immunological characteristics allows an accurate diagnosis in most cases of B cell chronic lymphoproliferative disorders (CLD). However, the diagnosis remains uncertain in a small percentage of cases, often referred as to unclassified B cell proliferation or atypical chronic lymphocytic leukemia (CLL). We have studied retrospectively the 192 cases of leukemic CLD seen in our institution over a 3-year period, for which both clinical and routine biological data at presentation were available. Forty cases (20%) did not fit into any of the well-identified categories according to the FAB criteria and remained unclassified. We assessed cyclin D1 expression in all of these cases and found that 10 of them expressed a high level of cyclin D1 protein. We compared the characteristics of these 10 cases with those of the 30 cyclin D1 negative CLD. Despite non-distinctive cytological and phenotypic features, the 10 cyclin D1 positive patients exhibited a strikingly uniform clinical presentation with elevated leukocytosis, massive spleen enlargement and no superficial lymphadenopathy. Their outcome was very poor with a median survival of 10 months, contrasting with the prolonged survival of the cyclin D1 negative patients. The cytological features of tumor cells from these 10 patients with cyclin D1 positive unclassified leukemic CLD were similar to those of the circulating lymphoid cells from 15 patients with histologically proven mantle cell lymphoma (MCL) and primary or secondary blood involvement. Therefore, cyclin D1 expression allowed identification among the unclassified CLD, a subset of aggressive disorders which represent a leukemic counterpart of MCL (mantle cell leukemia). We suggest that determination of cyclin D1 expression by any technique available should be systematically included when investigating atypical CLL.
Assuntos
Ciclina D1/genética , Regulação Neoplásica da Expressão Gênica/fisiologia , Leucemia de Células B/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Leucemia de Células B/diagnóstico , Leucemia de Células B/mortalidade , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida , Resultado do TratamentoRESUMO
We report the first case of full-term pregnancy arising from donated oocytes in a 36-year-old woman with chronic myeloid leukemia (CML), 6 years after allogeneic bone marrow transplantation (BMT) following total body irradiation (TBI) (12 Gy) and cyclophosphamide 120 mg/kg. The first attempt at implantation with her own cryopreserved ovocytes was unsuccessful. Thereafter, she became pregnant after donated oocyte implantation using estradiol and progesterone support replacing the defective ovarian function. The baby was normal. Unfortunately, 6 months later, she relapsed in chronic phase of CML.
Assuntos
Transplante de Medula Óssea , Transferência Embrionária , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Oócitos , Resultado da Gravidez , Adulto , Ciclofosfamida/administração & dosagem , Estradiol/uso terapêutico , Feminino , Humanos , Recém-Nascido , Infertilidade Feminina/etiologia , Leucemia Mieloide de Fase Crônica/etiologia , Ovário/efeitos da radiação , Gravidez , Insuficiência Ovariana Primária/tratamento farmacológico , Insuficiência Ovariana Primária/etiologia , Progesterona/uso terapêutico , Lesões por Radiação/etiologia , Doadores de Tecidos , Irradiação Corporal Total/efeitos adversosRESUMO
c-Jun, a transcriptional activator, as well as cyclin D1, a key regulator of the cell cycle, have been described in vitro as mediators of programmed neuronal death. After trophic factor deprivation, the activation of c-jun and cyclin D1 genes is considered as a necessary step within the cellular machinery that leads to cell death. We show here that both c-Jun and cyclin D1 proteins are present in neurones within the infarcted area after experimental cerebral ischaemia in the mouse. Since their presence was associated with DNA fragmentation revealed by the TUNEL procedure, we propose that c-Jun and cyclin D1 are involved in the process of neuronal death.
Assuntos
Apoptose , Encéfalo/patologia , Ciclinas/biossíntese , Ataque Isquêmico Transitório/patologia , Neurônios/patologia , Proteínas Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas c-jun/biossíntese , Animais , Encéfalo/fisiopatologia , Morte Celular , Ciclina D1 , Fragmentação do DNA , Regulação da Expressão Gênica , Genes jun , Imuno-Histoquímica/métodos , Ataque Isquêmico Transitório/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Neurônios/fisiologia , Especificidade de Órgãos , Proteína Supressora de Tumor p53/análise , Proteína Supressora de Tumor p53/biossínteseRESUMO
Pregnancy coexisting with evolutive malignant blood disease (Hodgkin's disease, acute leukemia, non-Hodgkin's lymphoma, chronic myeloproliferative disorder) is a therapeutic dilemma because of possible adverse reactions associated with the use of cytostatic agents. Therapeutic abortion, when needed, must be proposed only after a careful evaluation of the following parameters: the emergency of treatment, the prognosis of the disease, the term of pregnancy, the risks of therapy for the foetus and the mother, and the psychosocial context. From the clinical data published so far, the teratogenicity of cytostatic drugs seems to be minimal after the second trimester, and the outcome of pregnancy is often favorable, whatever the hemopathy. Radiation therapy must be used very cautiously and only in supradiaphragmatic areas. An overview of specific problems is done for each category of malignant blood disease.
Assuntos
Corticosteroides/uso terapêutico , Antineoplásicos/efeitos adversos , Transtornos Linfoproliferativos/terapia , Complicações Hematológicas na Gravidez/terapia , Complicações Neoplásicas na Gravidez/terapia , Aborto Terapêutico , Corticosteroides/efeitos adversos , Adulto , Animais , Antineoplásicos/uso terapêutico , Terapia Combinada , Feminino , Morte Fetal , Feto/efeitos dos fármacos , Feto/efeitos da radiação , Humanos , Recém-Nascido , Gravidez , Complicações Hematológicas na Gravidez/epidemiologia , Complicações Hematológicas na Gravidez/mortalidade , Complicações Neoplásicas na Gravidez/epidemiologia , Complicações Neoplásicas na Gravidez/mortalidade , Dosagem Radioterapêutica , RiscoRESUMO
We present our results of a MACOP-B regimen in a series of 46 patients with high-grade NHL. The complete remission rate was 74% for patients with advanced stage disease. The excellent tolerance allowed this regimen to be given on an outpatient basis in the majority of cases. The median follow-up for the living patients is 28 months. Although some patients received additional treatment that could influence the results, the predicted DFS (disease-free survival) at 45 months of 57% compares favorably with the best results published so far with more toxic regimens.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linfoma não Hodgkin/tratamento farmacológico , Adulto , Idoso , Assistência Ambulatorial , Bleomicina/uso terapêutico , Ciclofosfamida/uso terapêutico , Doxorrubicina/uso terapêutico , Tolerância a Medicamentos , Feminino , Humanos , Masculino , Metotrexato/uso terapêutico , Pessoa de Meia-Idade , Prednisolona/uso terapêutico , Estudos Prospectivos , Taxa de Sobrevida , Resultado do Tratamento , Vincristina/uso terapêuticoAssuntos
Perfilação da Expressão Gênica , Imunoglobulinas/genética , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Linfócitos B , Análise Mutacional de DNA , Progressão da Doença , Humanos , Reação em Cadeia da Polimerase , Análise de Componente Principal , PrognósticoRESUMO
Identification of the genes that control passage through the G1 phase of the cell cycle in mammalian cells is of particular interest because virtually all external events that regulate proliferation act primarily or exclusively during G1. Cyclins are likely to play a key role in controlling cell cycle progression, although their role during G1 in higher eukaryotic cells is unclear. In the hematopoietic cell line 32Dcl3, both cyclins D2 and D3 were expressed in proliferating cells, while cyclin D1 was undetectable. Expression of D2, and to a lesser extent D3, was interleukin 3 (IL-3) dependent and declined rapidly in the absence of this growth factor. To investigate the potential role of D cyclins in regulating cell growth, cell lines overexpressing either D2 or D3 were generated by transfection. Constitutive overexpression of either D2 or D3 did not affect cell viability, rate of cell proliferation, or dependence on IL-3 for growth. However, the distribution of cells through the cell cycle was dramatically altered, with both cyclins causing an increase in the fraction of cells in S phase, apparently related to a shortening of G1. Also, when deprived of IL-3, D3-overexpressing cells failed to arrest in G1, and apoptotic cell death in the absence of IL-3 was delayed. These results suggest a role for cyclins D2 and D3 in controlling passage of hematopoietic cells through G1 in the presence of growth factors and in effecting G1 arrest in the absence of growth factors.
Assuntos
Ciclo Celular , Ciclinas/fisiologia , Células-Tronco Hematopoéticas/citologia , Animais , Apoptose , Ciclina D2 , Ciclina D3 , Expressão Gênica , Interleucina-3/farmacologia , Camundongos , RNA Mensageiro/genéticaRESUMO
B-cell chronic lymphocytic leukemia (B-CLL) is characterized by the accumulation of resting lymphocytes. The identification of p27(kip1), a cyclin-dependent kinase inhibitor that contributes to cell cycle arrest and represents a link between extracellular signals and cell cycle, prompted us to study p27 protein in the lymphocytes from 88 patients with B-CLL and 32 patients with other chronic B-lymphoproliferative disorders. The expression of p27 protein was higher in B-CLL samples with variations among them. In B-CLL, p27 levels were independent of absolute number of circulating lymphocytes, but strongly correlated with both lymphocyte and total tumor mass (TTM) doubling time. High p27 expression was associated with a poorer overall prognosis. In vitro, there was an increased spontaneous survival of B-CLL cells expressing high p27 levels. Interleukin-4 (IL-4) upregulated p27 levels in B-CLL cells, while fludarabine decreased p27 levels. Thus, our results indicate that p27 may be a valuable kinetic marker in B-CLL by providing instantaneous estimation of the disease doubling time. In addition, these results suggest that there is a link between p27 expression and the ability of CLL cells to undergo apoptosis.
Assuntos
Biomarcadores Tumorais , Proteínas de Ciclo Celular , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Proteínas Associadas aos Microtúbulos/biossíntese , Proteínas Supressoras de Tumor , Apoptose , Ciclo Celular , Inibidor de Quinase Dependente de Ciclina p27 , Quinases Ciclina-Dependentes/antagonistas & inibidores , Genes Supressores de Tumor , Humanos , PrognósticoRESUMO
Accurate identification of B-cell chronic malignancies is sometimes uncertain, despite careful cytologic and immunophenotypic evaluation. Cytogenetics and molecular biology studies may therefore prove useful, because some of these disorders are associated with non-random abnormalities, such as the t(11;14)(q13;q32) translocation and bcl-1 rearrangement mainly observed in mantle-cell lymphoma (MCL). We studied the expression of cyclin D1 in malignant lymphoid cells from the peripheral blood of 32 patients with various B-cell chronic lymphoproliferative disorders, using Northern blot (NB) and RNA in situ hybridization (ISH). Cytogenetic analysis was informative in 18 cases, and most of the missing karyotype data were from typical B-CLL cases where a t(11;14) is unlikely to be found. Over-expression of cyclin D1 mRNA was observed by both NB and ISH in four samples (MCL; two cases; lymphoplasmacytic lymphoma: one case, unclassified B-cell chronic disorder: one case). In each of these cases there was an abnormality of chromosome 11q13, either a t(11;14)(q13;q32) translocation (three cases) or a del(11)(q13) without evidence of chromosome 14 involvement (one case). Cytogenetic and gene rearrangement studies are not available in all institutions and have some technical pitfalls. Because of its close association with bcl-1 rearrangement and/or t(11;14), the demonstration of cyclin D1 mRNA over-expression either by NB, or, more conveniently, by ISH, may represent additional information which could be of help for the identification of B-cell malignancies.
Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 11 , Ciclinas/genética , Linfoma de Células B/diagnóstico , Proteínas Oncogênicas/genética , Idoso , Apoptose , Northern Blotting , Ciclina D1 , Feminino , Citometria de Fluxo , Humanos , Hibridização In Situ , Pessoa de Meia-Idade , Translocação Genética , TrissomiaRESUMO
Tumor progression in B-cell chronic lymphocytic leukemia (B-CLL) is thought to result from the gradual accumulation of small resting G0/G1 phase lymphoid cells rather than the proliferation of actively dividing cells. The recent identification of G1 cyclins that are likely to control both the progression through G0 and G1 phase and the G1/S transition prompted us to study the mRNA expression of D-type cyclins in the peripheral blood lymphocytes from 34 patients with B-CLL, 7 patients with lymphoplasmacytic lymphoma (LPL), and 2 patients with mantle cell lymphoma (MCL). Cyclin D2 mRNA was, on average, 5- to 10-fold overexpressed in most of the samples studied (B-CLL, 29/34; LPL, 7/7; MCL, 0/2) as compared with normal resting B lymphocytes, in which cyclin D2 mRNA was barely detectable. In situ hybridization with cyclin D2 digoxigenin-labeled mRNA probe showed that all the cells from a given sample were stained with approximately the same intensity. Cyclin D3 was never detected in any of the samples tested, whereas cyclin D1 was expressed in only the 3 cases (1 LPL and 2 MCL) bearing a t(11;14) translocation. A trisomy 12 was found in 4 of 19 (21%) B-CLL or LPL cases for which cytogenetic analysis was available. Although the cyclin D2 gene has been mapped to chromosome 12p13, there was no apparent correlation between trisomy 12 and the level of cyclin D2 expression. Cell cycle analysis by flow cytometry after staining with propidium iodide consistently showed that more than 96% of the cells were in G0/G1 phase, whatever the importance of cyclin D2 overexpression was, and that cyclin D2 overexpression in B-CLL was not associated with any modifications of the cell cycle repartition. No consistent overexpression of cyclin D2 was found in acute myeloid leukemias. In conclusion, overexpression of cyclin D2 mRNA was found to be an almost constant feature in B-CLL and LPL. Therefore, it led us to hypothesize, with the support of data from some transfection experiments previously reported in murine hematopoietic cell lines, that cyclin D2 might play a role in B-CLL pathogenesis, possibly by preventing cells from programmed cell death.
Assuntos
Quinases Ciclina-Dependentes , Ciclinas/genética , Leucemia Linfocítica Crônica de Células B/genética , Linfoma não Hodgkin/genética , Proteínas Proto-Oncogênicas , Ciclina D2 , Ciclina D3 , Quinase 4 Dependente de Ciclina , Expressão Gênica , Humanos , Hibridização In Situ , Leucemia Linfocítica Crônica de Células B/patologia , Linfoma não Hodgkin/patologia , Proteínas Serina-Treonina Quinases/genética , RNA Mensageiro/genética , RNA Neoplásico/genéticaRESUMO
The study analysed the financial benefits of transplantation with peripheral blood stem-cells primed after chemotherapy and growth factor in comparison with bone marrow transplantation. Twenty-three consecutive transplantations were performed during one year: 14 peripheral blood stem-cell (CSC group) and 9 bone marrow transplantations (MO group). No differences in patients characteristics were seen between the two groups except for higher number of "BEAM" conditioning in CSC group. Were analyzed delay in neutrophil and platelet recovery, numbers of days in hospital, with fever, under antibiotics, costs of supportive therapy, stem-cell collection and cryopreservation. Difference was significant for duration of neutropenia with advantages in CSC group, but the number on days in hospital, with fever or under antibiotics were similar. Number of platelet transfusions was reduced in CFC group: this economical advantage was lost with the cost of growth factor used for priming stem-cells stem-cell collections and cryopreservations. In our retrospective study, financial advantages associated to peripheral blood stem-cell transplantation was not verified.