Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 101
Filtrar
1.
Leuk Lymphoma ; 42(1-2): 89-98, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11699226

RESUMO

We treated 33 patients with a variant of the standard 3 weekly CHOP regime, replacing doxorubicin with liposomal daunorubicin (DaunoXome, NeXstar Pharmaceuticals) 120 mg/m2 (COP-X). Eighteen subjects had relapsed/refractory aggressive NHL and 15 had indolent NHL/CLL. Median number of courses received was 4 (1-8). Thirty-two patients were evaluable for efficacy and 26 (81%) responded. 88% of patients with aggressive NHL responded; three (18%) patients achieved complete remission (CR), 12 (70%) achieved partial remission (PR), 1 (6%) patient had stable disease (SD) and 1 (6%) patient progressed through treatment. Median duration of response for patients with aggressive NHL was 3 months. The response rate in indolent NHL/CLL was 73%. Four (27%) patients achieved CR, 7 (46%) PR and 4 (27%) SD. At two years post treatment, 55% of the patients with indolent NHL/CLL remain progression-free, although 4 patients have proceeded to consolidation therapy. Twenty-seven out of 28 (96%) patients developed neutropenia of short duration following one or more of their treatments. Twenty-three patients developed an infection at some stage during therapy (all associated with neutropenia) and required hospitalisation. There were two toxic deaths (infection) both of which occurred in patients who were neutropenic before starting COP-X. Platelet toxicity was mild in patients with normal platelet counts at the commencement of therapy. Alopecia and mucositis were mild. No clinical evidence of myocardial failure was observed. We conclude that the substitution of DaunoXome for doxorubicin in the CHOP regimen to form COP-X provides excellent efficacy against non-Hodgkin's lymphoma. Response durations were short but comparable to those reported with other regimens. COP-X was well tolerated with some suggestion of reduced non-haematological toxicity. The regimen should be considered as an alternative to CHOP with potentially less non-haematological toxicity, particularly cardiac; further studies are required to evaluate the regimen in this context.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Daunorrubicina/administração & dosagem , Linfoma não Hodgkin/tratamento farmacológico , Terapia de Salvação/métodos , Idoso , Antibióticos Antineoplásicos/toxicidade , Protocolos de Quimioterapia Combinada Antineoplásica/toxicidade , Ciclofosfamida/administração & dosagem , Daunorrubicina/toxicidade , Feminino , Humanos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Lipossomos/administração & dosagem , Masculino , Pessoa de Meia-Idade , Prednisolona/administração & dosagem , Prognóstico , Indução de Remissão , Análise de Sobrevida , Equivalência Terapêutica , Resultado do Tratamento , Vincristina/administração & dosagem
2.
Biochem Biophys Res Commun ; 287(1): 181-9, 2001 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-11549272

RESUMO

Tumor necrosis factor-alpha (TNFalpha) mediates cytochrome c release from mitochondria, loss of mitochondrial membrane potential (DeltaPsim) and apoptosis in sensitive leukemic cells. In the present study, by using the human leukemic U937 cell line, we demonstrate that the cytochrome c release is caspase-8-dependent and can be blocked by an inhibitor of caspase-8, Z-Ile-Glu (OMe)-Thr-Asp(OMe)-fluoromethyl ketone (Z-IETD.fmk), or a pan caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone (Z-VAD.fmk). However, TNFalpha-mediated loss of DeltaPsim was not inhibited by caspase inhibitors. The apoptotic process was blocked by either Z-IETD.fmk or Z-VAD.fmk in cells with lower DeltaPsim. U937 cells with stable transfection of the cellular inhibitor of apoptosis protein 1 (c-IAP1) are resistant to TNFalpha-induced activation of caspases, Bid cleavage, cytochrome c release and DeltaPsim collapse. In addition, both c-IAP1 and XIAP were not up-regulated upon prolonged exposure to TNFalpha. In contrast, there was a caspase-dependent cleavage of XIAP, but not c-IAP1, during treatment with TNFalpha for 7 days. These results demonstrate that c-IAP1 blocks TNFalpha signaling at a level controlling both activation of caspase-8 and a signal to cause loss of DeltaPsim. The sensitive U937 cell line failed to acquire resistance and gain a self-protecting advantage against apoptosis, upon induction of c-IAP1 expression.


Assuntos
Apoptose , Caspases/metabolismo , Mitocôndrias/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia , Proteínas Virais/farmacologia , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3 , Proteínas de Transporte/metabolismo , Caspase 3 , Caspase 8 , Caspase 9 , Inibidores de Caspase , Grupo dos Citocromos c/metabolismo , Interações Medicamentosas , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Humanos , Proteínas Inibidoras de Apoptose , Leucemia/patologia , Potenciais da Membrana/efeitos dos fármacos , Mitocôndrias/enzimologia , Mitocôndrias/fisiologia , Proteínas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transfecção , Células Tumorais Cultivadas , Células U937 , Raios Ultravioleta , Proteínas Virais/genética , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X
3.
Oncogene ; 20(35): 4817-26, 2001 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-11521193

RESUMO

Bax translocation from cytosol to mitochondria is believed to be a crucial step for triggering cytochrome c release from mitochondria. However, it is unclear whether Bax translocation is associated with Bax induction by DNA damaging agents. The induction of Bax in response to DNA damaging agents has been considered to be linked with p53. In this study, we used the p53 negative human chronic myeloid leukaemia K562 cell line. Bax up-regulation occurred at the whole cell level after DNA damage induced by etoposide. However, after incubation with etoposide, Bax failed to translocate to mitochondria and as a result, the apoptotic process was blocked. A Bax stable transfectant, the K/Bax cell line, expressed more Bax protein in the cytosol, mitochondria and nuclei. This Bax overexpression induced cytochrome c release, a reduction of cytochrome c oxidase activity and mitochondrial membrane potential (Delta(Psi)m). However, Bax-induced apoptosis was blocked downstream of mitochondria in K562 cells. The increased levels of mitochondrial Bax sensitized cells to etoposide-induced activation of caspases-2, -3 and -9 and apoptosis. However, after transient transfection with the Apaf-1 gene, K/Bax cells were sensitized to etoposide-induced caspase activation and apoptosis to a larger extent compared with Bax or Apaf-1 transfection alone. We therefore conclude that two mechanisms contribute to the resistance of K562 cells to etoposide-induced apoptosis; firstly failure of Bax targeting to mitochondria and, secondly, deficiency of Apaf-1. Uncoupling of Bax translocation from Bax induction can occur in response to etoposide-induced DNA damage.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Etoposídeo/farmacologia , Leucemia/tratamento farmacológico , Proteínas Proto-Oncogênicas c-bcl-2 , Proteínas Proto-Oncogênicas/metabolismo , Fator Apoptótico 1 Ativador de Proteases , Transporte Biológico , Caspases/fisiologia , Dano ao DNA , Humanos , Células K562 , Leucemia/patologia , Proteínas/fisiologia , Proteína X Associada a bcl-2
4.
Apoptosis ; 6(4): 269-78, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11445669

RESUMO

Quantitation of apoptotic cell death in vivo has become an important issue for patients with acute leukemia. We describe herein a new analytical method, based on infrared (IR) spectroscopy, to estimate the percentage of apoptotic leukemic cells in two different cell lines (CEM and K562), induced with etoposide (VP-16). As the percentage of apoptosis increases, the protein structure shifts from dominantly beta-sheet to unordered (random coil), the overall lipid content increases and the amount of detectable DNA decreases. These changes can be directly related to the percentage of apoptosis as determined by two standard reference methods: flow cytometry and DNA ladder formation. The correlation between the significant IR spectral changes and the percentage of apoptotic leukemia cells in the two cell lines was optimal up to 24 h following etoposide treatment (r = 0.99 for CEM cells and r = 0.96 for K562 cells). Furthermore, IR spectroscopy is able to detect apoptotic changes in these cells already after 4 h treatment with VP-16, compared to flow cytometry which needs 6 h to observe significant changes. Our study suggests that IR spectroscopy may have potential clinical utility for the early, fast and reagent free assessment of chemotherapeutic efficacy in patients with leukemia.


Assuntos
Apoptose , Leucemia/patologia , Espectrofotometria Infravermelho , Contagem de Células , Etoposídeo/farmacologia , Citometria de Fluxo , Células Tumorais Cultivadas
5.
Blood ; 98(2): 414-21, 2001 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-11435311

RESUMO

The human leukemia cell lines K562, CEM, CEM/VLB(100), human leukemic blasts, and the bladder cancer J82 cell line have different sensitivities to UV light-induced apoptosis. It is reported that resistance to UV light-induced apoptosis occurs at a point in the apoptotic pathway upstream of caspase-3 but downstream of mitochondrial cytochrome c release. It is demonstrated that the block is due to deficiency of Apaf-1, a critical member of the apoptosome. Sensitivity to apoptosis was independent of caspase-9b or XIAP (inhibitors of apoptosis proteins) expression or levels of procaspase-9. Transfection of Apaf-1 conferred sensitivity to apoptosis in resistant cells. Apaf-1 deficiency may constitute a significant mode of resistance to apoptosis in human leukemia.


Assuntos
Apoptose , Grupo dos Citocromos c/metabolismo , Proteínas/análise , Anticorpos/farmacologia , Apoptose/efeitos dos fármacos , Fator Apoptótico 1 Ativador de Proteases , Caspase 3 , Caspase 9 , Caspases/análise , Caspases/metabolismo , Grupo dos Citocromos c/farmacologia , Ativação Enzimática/efeitos dos fármacos , Granzimas , Humanos , Leucemia Mieloide Aguda , Leucemia-Linfoma de Células T do Adulto , Precursores de Proteínas/metabolismo , Proteínas/genética , Proteínas/imunologia , Proteínas/metabolismo , Serina Endopeptidases/farmacologia , Transfecção , Células Tumorais Cultivadas , Raios Ultravioleta , Neoplasias da Bexiga Urinária , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X
6.
Biochem Biophys Res Commun ; 283(5): 1037-45, 2001 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-11355877

RESUMO

We have previously shown that Bax translocation was crucial in TNFalpha or etoposide-induced apoptosis. Overexpression of Bax sensitized chronic myeloid leukemic K562 cells to etoposide-induced apoptosis. Treatment with TNF-related apoptosis-inducing ligand (TRAIL) induces a loss of mitochondrial membrane potential (DeltaPsim), cytochrome c release from mitochondria, activation of caspases-8, -9, and -3, and cleavage of Bid in the K562 cell line. Bax failed to sensitize K562 cells to TRAIL-induced apoptosis. TRAIL did not induce Bax expression and/or translocation from cytosol to mitochondria in the K562 cell line. However, 100 microM Z-VAD.fmk, a pan caspase inhibitor, completely blocked TRAIL-initiated mitochondrial alterations and cleavages of caspases and Bid. We propose that TRAIL-induced apoptosis in K562 cells is via Type I apoptotic signal pathway. Bax translocation is not essential for TRAIL-induced cytochrome c release and DeltaPsim collapse in the Type I cells.


Assuntos
Apoptose/fisiologia , Glicoproteínas de Membrana/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2 , Fator de Necrose Tumoral alfa/farmacologia , Clorometilcetonas de Aminoácidos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3 , Proteínas de Transporte/metabolismo , Caspase 3 , Caspase 8 , Caspase 9 , Caspases/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Grupo dos Citocromos c/metabolismo , Precursores Enzimáticos/metabolismo , Humanos , Membranas Intracelulares/fisiologia , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Mitocôndrias/fisiologia , Proteínas Proto-Oncogênicas/genética , Proteínas Recombinantes/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF , Transfecção , Proteína X Associada a bcl-2
7.
Leuk Res ; 25(5): 423-31, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11301111

RESUMO

These data show that 8-Cl-cAMP is cytotoxic to the lymphoblastic leukemia cell line CEM and its vinblastine selected multidrug resistant derivative, CEM/VLB100 although PKA was not involved in these effects. The cytotoxic effects of 8-Cl-cAMP was abrogated by cotreatment with either ADA or IBMX which indicated a degradation form of 8-Cl-cAMP was needed for this cytotoxicity. CEM and CEM/VLB100 cells displayed a notable sensitivity to 8-Cl-adenosine-induced growth inhibition and apoptosis. 8-Cl-adenosine increased the cytosolic levels of IkappaBalpha which prevented NF-kappaB nuclear translocation. 8-Cl-adenosine also prevented TNFalpha-induced IkB decay and NF-kappaB activation in CEM and CEM/VLB100 cells.


Assuntos
2-Cloroadenosina/análogos & derivados , 2-Cloroadenosina/farmacologia , 8-Bromo Monofosfato de Adenosina Cíclica/análogos & derivados , Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Proteínas I-kappa B , Leucemia de Células T/tratamento farmacológico , NF-kappa B/fisiologia , Fator de Necrose Tumoral alfa/farmacologia , 2-Cloroadenosina/administração & dosagem , 2-Cloroadenosina/farmacocinética , 8-Bromo Monofosfato de Adenosina Cíclica/administração & dosagem , 8-Bromo Monofosfato de Adenosina Cíclica/farmacocinética , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Antineoplásicos Fitogênicos/farmacologia , Biotransformação , Divisão Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos , Inibidores do Crescimento/farmacologia , Humanos , Leucemia de Células T/metabolismo , Leucemia de Células T/patologia , Inibidor de NF-kappaB alfa , NF-kappa B/biossíntese , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa/administração & dosagem , Regulação para Cima/efeitos dos fármacos , Vimblastina/farmacologia
8.
Biochem Biophys Res Commun ; 282(1): 268-72, 2001 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-11264002

RESUMO

Apaf-1 plays a crucial role in the cytochrome c/dATP-dependent activation of caspase-9 and -3. We found that the human myeloid leukemic K562 cells were more resistant to cytochrome c-induced activation of caspase-9 and -3 in a cell-free system compared with the human T-lymphoblastic subclone CEM/VLB(100) cells. Apaf-1 cDNA sequencing revealed an additional insert of 11 aa between the CARD and CED-4 (ATPase) domains in K562 cells, which was identical to the sequence of Apaf-1XL. Immunoprecipitation of Apaf-1 with caspase-9 after a cell-free reaction demonstrated that Apaf-1XL in the K562 cell line showed a lower binding ability to caspase-9 compared with Apaf-1L protein. The resistance of K562 cells to cytochrome c-dependent apoptosis may be partly due to this Apaf-1XL form. These results suggest that the additional insert between CARD and CED-4 domains might affect Apaf-1 recruitment of caspase-9 during apoptosis.


Assuntos
Isoformas de Proteínas/metabolismo , Proteínas/metabolismo , Adenosina Trifosfatases/metabolismo , Fator Apoptótico 1 Ativador de Proteases , Caspase 3 , Caspase 9 , Caspases/metabolismo , Grupo dos Citocromos c/metabolismo , DNA Complementar , Ativação Enzimática , Humanos , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Proteínas/química , Proteínas/genética , Células Tumorais Cultivadas
9.
Br J Haematol ; 115(4): 817-25, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11843815

RESUMO

The anthracycline antibiotic idarubicin (IDA) induces double-stranded DNA breaks, the generation of reactive oxygen species (ROS) and apoptosis in human leukaemic cells. It is unclear whether the generation of ROS is associated with the apoptotic process. Using the T-lymphoblastic leukaemic CEM cell line, we found that IDA-induced DNA breaks were correlated with final cell death. The reduction in mitochondrial membrane potential (Deltapsim) and the generation of ROS occurred simultaneously with IDA-induced activation of caspase-9 and caspase-3. Inhibition of caspases by a pan-caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone (Z-VAD-fmk) completely blocked IDA-induced reduction of Deltapsim, apoptosis and final cell death. Interestingly, ROS generation was significantly enhanced by Z-VAD-fmk. ROS generation was neither caspase dependent nor part of the apoptotic process. IDA-mediated reduction in Deltapsim is caspase dependent and is not a consequence of the generation of ROS. These results indicate that IDA-induced generation of ROS and apoptosis are separate events. Inhibition of caspases facilitates IDA-mediated generation of ROS.


Assuntos
Antibióticos Antineoplásicos/efeitos adversos , Apoptose , Dano ao DNA , Idarubicina/efeitos adversos , Leucemia-Linfoma de Células T do Adulto/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Clorometilcetonas de Aminoácidos/farmacologia , Caspase 3 , Caspase 9 , Inibidores de Caspase , Caspases/metabolismo , Morte Celular , Linhagem Celular , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Humanos , Potenciais da Membrana/efeitos dos fármacos , Mitocôndrias/fisiologia
10.
Med Oncol ; 17(4): 333-6, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11114714

RESUMO

A 36-year-old man underwent matched unrelated donor bone marrow transplantation for chronic myeloid leukaemia. He developed severe hepatic veno-occlusive disease as an early post-transplant complication. Tissue plasminogen activator was initially felt to be contraindicated since the patient had concomitant pericarditis. Defibrotide was therefore commenced as treatment for veno-occlusive disease. The pericarditis improved but the veno-occlusive disease continued to worsen (peak bilirubin 353 micromol/l). Tissue plasminogen activator followed by a heparin infusion was therefore administered. However, he proceeded to develop haemorrhagic cardiac tamponade that required drainage. Thrombolysis was therefore discontinued and treatment with defibrotide resumed after an interval of 48 h. The veno-occlusive disease gradually resolved and defibrotide was discontinued once the bilirubin had plateaued. He was discharged home on day +52 post-transplant.


Assuntos
Transplante de Medula Óssea/efeitos adversos , Fibrinolíticos/uso terapêutico , Hepatopatia Veno-Oclusiva/tratamento farmacológico , Hepatopatia Veno-Oclusiva/etiologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Polidesoxirribonucleotídeos/uso terapêutico , Ativador de Plasminogênio Tecidual/uso terapêutico , Adulto , Tamponamento Cardíaco , Humanos , Masculino , Pericardite , Transplante Homólogo , Resultado do Tratamento
11.
Br J Haematol ; 111(3): 807-16, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11122142

RESUMO

The signal transduction pathway through which tumour necrosis factor (TNF) induces apoptosis in leukaemic cells may involve activation of cytosolic phospholipase A(2) (cPLA(2)). The steroids dexamethasone (Dex) and 1,25(OH)(2) D(3) both render U937 leukaemic cells resistant to TNF-induced apoptosis. In this study, we found that Dex inhibited both spontaneous and TNF-induced activation of cPLA(2). Dex had no direct effect on cellular cPLA(2) levels, but facilitated cPLA(2) degradation upon subsequent stimulation of cells with TNF. In addition, Dex increased synthesis of the endogenous cPLA(2) inhibitor lipocortin 1 (LC1). An antisense oligonucleotide to LC1 could completely abrogate Dex-induced resistance to the cytotoxic action of TNF. Constitutive LC1 levels were relatively higher in myeloid leukaemic blasts showing resistance to TNF than TNF-sensitive myeloid leukaemic cell lines. Our data suggest that Dex confers the resistance of U937 cells to TNF-induced apoptosis by upregulating intracellular levels of LC1 and by facilitating a negative-feedback loop, which is activated upon stimulation with TNF. High constitutive levels of LC1 in leukaemic blasts may protect them against immune-mediated killing.


Assuntos
Anexina A1/metabolismo , Antineoplásicos Hormonais/farmacologia , Dexametasona/farmacologia , Leucemia/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia , Doença Aguda , Anexina A1/genética , Apoptose/efeitos dos fármacos , Ácido Araquidônico/metabolismo , Calcimicina/farmacologia , Linhagem Celular , Citosol/enzimologia , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/metabolismo , Retroalimentação , Humanos , Ionóforos/farmacologia , Leucemia Monocítica Aguda/metabolismo , Leucemia Mieloide/metabolismo , Oligonucleotídeos Antissenso/farmacologia , Fosfolipases A/antagonistas & inibidores , Fosfolipases A/metabolismo , Estimulação Química
12.
Ann Oncol ; 11(7): 857-60, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10997814

RESUMO

BACKGROUND: Although lymphoid malignancies are generally chemosensitive, relapse is common. The use of high-dose therapy can make subsequent cytotoxic therapy intolerable. There is a need to develop regimens with low acute toxicity which are suitable for use in patients post-high dose therapy and following the failure of standard protocols. PATIENTS AND METHODS: Twenty-six patients with lymphomas, fifteen of whom had received high-dose therapy, were treated with a novel regimen consisting of low-dose lomustine, chlorambucil, daily subcutaneous bleomycin, vincristine and methotrexate with dexamethasone on an eight-week cycle (LBCMVD-56). A median of three cycles was given. RESULTS: The overall response rate at 12 weeks was 67% (21% complete remission (CR)) with a median overall survival of 13 months. A symptomatic response was seen in 72%. Previous high-dose therapy did not compromise the response rate. Toxicity was acceptable with grade 3-4 haematological toxicity seen in 27% of cycles, gastrointestinal toxicity seen in 11% and pulmonary toxicity seen in 8%. Thirty-one percent of patients required hospitalisation at some point during this treatment most commonly for neutropenic sepsis. CONCLUSIONS: LBCMVD-56 is an inexpensive, outpatient-based regimen with low acute toxicity and a high response rate in this heavily pre-treated group of patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Doença de Hodgkin/tratamento farmacológico , Linfoma não Hodgkin/tratamento farmacológico , Adolescente , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Bleomicina/administração & dosagem , Clorambucila/administração & dosagem , Dexametasona/administração & dosagem , Esquema de Medicação , Feminino , Doença de Hodgkin/patologia , Hospitalização , Humanos , Infusões Intravenosas , Injeções Subcutâneas , Lomustina/administração & dosagem , Linfoma não Hodgkin/patologia , Masculino , Metotrexato/administração & dosagem , Pessoa de Meia-Idade , Neutropenia/induzido quimicamente , Sepse/induzido quimicamente , Resultado do Tratamento , Vincristina/administração & dosagem
13.
Br J Haematol ; 109(3): 571-5, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10886206

RESUMO

We report the results of a non-randomized pilot study of an oral regimen comprising CCNU (lomustine; 25 or 50 mg/m2 on day 1), idarubicin (4-demethoxydaunorubicin) (10 mg/m2 on days 1-3) and dexamethasone (10 mg b.d. on days 1-4) in patients with relapsed or refractory myeloma. Treatment was given every 28 d for a maximum of six courses. Sixty patients were entered of whom 57 were evaluable. Overall response rate (partial or minor response) was 49% with 30% of patients achieving a partial response (50% tumour reduction). Response rates were higher in patients with untested relapse than in those with refractory disease (overall response rates 56% vs. 31%). The major toxicity was neutropenia and the regimen was otherwise well tolerated. The median survival from entry of all patients was 15 months, with 30% of patients alive at 2 years. This regimen represents a useful addition to available treatment options.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/efeitos adversos , Antineoplásicos Alquilantes/administração & dosagem , Antineoplásicos Alquilantes/efeitos adversos , Antineoplásicos Hormonais/administração & dosagem , Antineoplásicos Hormonais/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Dexametasona/administração & dosagem , Dexametasona/efeitos adversos , Feminino , Humanos , Idarubicina/administração & dosagem , Idarubicina/efeitos adversos , Lomustina/administração & dosagem , Lomustina/efeitos adversos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/mortalidade , Neutropenia/induzido quimicamente , Projetos Piloto , Recidiva , Taxa de Sobrevida
14.
Blood Rev ; 14(1): 14-30, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10805258

RESUMO

Pooled human intravenous immunoglobulin (IVIg) has been used successfully to treat or ameliorate the clinical manifestations of humoral immune deficiencies, haematological disorders, HIV infection and many other diseases states. However, the mechanism of action of IVIg remains unclear. Several mechanisms of action of IVIg have been proposed. These include Fcy receptor blockade, accelerated clearance of endogenous pathogenic auto-antibodies, inhibition of components of the complement cascade, neutralization of super-antigens and bacterial toxins as well as anti-cytokine and anti-idiotype effects. A major contributor to host immunity and immune surveillance against infection, tissue or cell damage and malignancy is the monocyte/macrophage system. Monocyte-directed inflammation is a desirable consequence of microbiological or malignant challenge. However, monocyte hyperactivity may contribute to certain pathological conditions. These include the systemic inflammatory response syndrome (SIRS), septic shock, other dysregulated inflammatory disorders and auto-immunity. Novel therapies that can suppress the hyperactive state or correct monocyte/macrophage dysfunction without compromising normal host cell-mediated immunity are desirable. In this review, we discuss the immunomodulatory effects of IVIg focussing particularly upon the monocyte/macrophage system in pertinent disease states.


Assuntos
Adjuvantes Imunológicos/uso terapêutico , Imunoglobulinas Intravenosas/uso terapêutico , Macrófagos/imunologia , Monócitos/imunologia , Adjuvantes Imunológicos/química , Animais , Humanos , Imunoglobulinas Intravenosas/química , Síndromes de Imunodeficiência/terapia
15.
Leukemia ; 14(4): 620-8, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10764147

RESUMO

Alterations in the response of leukaemic cells to apoptosis-inducing stimuli may account for resistance to chemotherapy and treatment failure, either by disruption of the apoptotic pathway itself or by altered DNA repair; quiescent cells and those with disrupted cell-cycle checkpoints may also display decreased apoptosis. Quiescence can be induced by the differentiation of myeloid cells, and this led us to investigate whether the modulation of drug-induced apoptosis associated with differentiation might be a model for quiescence-associated resistance generally. We have demonstrated that resistance to idarubicin-induced apoptosis increased with greater duration of incubation of HL60 and U937 cells with ATRA and 1,25(OH)2 D3 and that this protective effect correlated with the degree of G0/G1 accumulation. In addition, the cytoprotective effects held for other classes of cytotoxic drugs with different mechanisms of action to idarubicin. Prolonged exposure to idarubicin or vinblastine was associated with diminution of the protective effect and re-entry of cells into cycle. The full cytoprotective effect was restored by resupplementation with ATRA or 1,25(OH)2 D3 during exposure to idarubicin, with concomitant persistence of G0/G1 accumulation. Differentiating agents prevented the accumulation of leukaemic cells at the G2/M checkpoint in response to low concentrations of idarubicin. Understanding how differentiating agents modulate these cell-cycle checkpoints, and how quiescent cells evade apoptosis, may allow the development of therapeutic strategies to limit such apoptosis-inhibiting effects and maximise cell kill from chemotherapy.


Assuntos
Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/fisiologia , Idarubicina/farmacologia , Leucemia Mieloide/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Vimblastina/farmacologia , Doença Aguda , Calcitriol/farmacologia , Diferenciação Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Fase G1/efeitos dos fármacos , Células HL-60/efeitos dos fármacos , Células HL-60/patologia , Humanos , Células-Tronco Neoplásicas/patologia , Fase de Repouso do Ciclo Celular/efeitos dos fármacos , Tretinoína/farmacologia , Células U937/efeitos dos fármacos , Células U937/patologia
16.
Br J Haematol ; 108(3): 565-73, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10759715

RESUMO

The cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) signal pathway regulates cell proliferation, differentiation and cell death. It may also regulate the multidrug resistance (MDR) phenotype in leukaemic cells. These data showed that MDR1+ K/Dau600 cells exhibited a higher basal level of PKA activity than MDR- parental cells. The significance of this on tumour necrosis factor alpha (TNFalpha)-induced apoptosis and cytostasis was investigated further. In comparison with MDR1- parental cells, K/Dau600 cells had a higher expression of PKA regulatory subunit RIalpha and nuclear catalytic subunit PKAcalpha. They were also more susceptible to inhibition of proliferation and induction of apoptosis by TNFalpha and/or forskolin, but this could be attenuated by H89. An increase in cAMP was associated with the apoptosis in the K/Dau600 cell line. Forskolin inactivated NF-kappaB in K/Dau600 cells but not in K562 cl. 6 cells, whereas TNF activated NF-kappaB in K562 cl.6 cells but not in K/Dau600 cells. 8-Cl-cAMP exhibited similar inhibitory effects on the proliferation of all of the cell lines used via its metabolite 8-Cl-adenosine, which indicates that these effects were independent of residual PKA or cAMP. Therefore, the differential sensitivity to apoptosis and/or growth inhibition could be mediated via cAMP, partly through PKA via NF-kappaB and partly by PKA-independent pathways.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Colforsina/uso terapêutico , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Leucemia/enzimologia , Sulfonamidas , 8-Bromo Monofosfato de Adenosina Cíclica/análogos & derivados , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Divisão Celular/efeitos dos fármacos , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Humanos , Isoquinolinas/farmacologia , Leucemia/tratamento farmacológico , Leucemia/metabolismo , NF-kappa B/metabolismo , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/uso terapêutico
17.
Leuk Res ; 24(4): 317-30, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10713329

RESUMO

Cytokines such as interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) activate monocytes both in vitro and in vivo. We therefore studied whether the anti-leukaemic activity of monocytes could be augmented by IL-3 alone or in combination with GM-CSF. Using normal human monocytes stimulated with IL-3, GM-CSF, LPS or combinations of growth factor and LPS, we studied their cytotoxic activity against leukaemic cell-lines and primary AML blasts. IL-3 like GM-CSF, augmented the expression and secretion of TNF but did not prime for further expression and secretion of TNF in response to LPS. Neither GM-CSF or IL-3 increased the expression or secretion of TNF receptor p55 (TNF-Rp55), although both agents increased expression of TNF receptor p75 (TNF-Rp75). Monocyte-mediated cytotoxicity (MMC) against K562 and U937 cell-lines was increased by both GM-CSF and IL-3 stimulation, and both cytokines primed monocytes for increased killing of K562 and KG-1 cell-lines as well as primary AML blasts in response to LPS. The mechanism of action of MMC was largely confirmed to be via surface-bound TNF, although other TNF-independent mechanisms must have been involved.


Assuntos
Citotoxicidade Imunológica/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Interleucina-3/farmacologia , Leucemia/imunologia , Monócitos/imunologia , Fator de Necrose Tumoral alfa/biossíntese , Humanos , L-Lactato Desidrogenase/metabolismo , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Receptores do Fator de Necrose Tumoral/biossíntese
18.
Bone Marrow Transplant ; 26(11): 1165-72, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11149726

RESUMO

Between October 1993 and March 1999, 29 patients with CML who were ineligible for allogeneic BMT underwent PBSC harvest using idarubicin, cytarabine and G-CSF. In 9/29 (31%) patients all collected stem cells were Ph-negative, and 15/29 patients' (52%) collections were substantially (>95%) Ph-negative. The proportion of patients from whom Ph-negative stem cells were obtained was similar between patients who had, or had not, received prior alphaIFN. Fifteen patients in chronic phase (median age 45) proceeded to PBSCT following busulphan 16 mg/m2 and cyclophosphamide 120 mg/m2. Nine of the 13 patients who had failed to respond to prior alphaIFN proceeded to stem cell transplantation as soon as was feasible and six of the newly diagnosed patients were transplanted after failing to achieve a cytogenetic response after a minimum of 12 months on alphaIFN following progenitor cell harvest. The median number of days to neutrophils >0.5 and platelet >50 was 18 (range 13-69) and 28 (range 13-234), respectively. There was no procedure-related mortality. At median follow-up of 2.3 years post autograft 10 of 15 patients remain alive and in chronic phase. Overall survival for all 27 patients at 5 years after initial diagnosis is 70% and median survival from diagnosis 7.3 years. Survival for alphaIFN non-responders who were transplanted is 74% at 5 years from diagnosis and 75% at 3 years from transplant. Cytogenetic analysis performed 3 months post transplant demonstrated one patient with a complete cytogenetic response, seven with a partial response and three with no response. Six patients remain partially Ph-negative, with one major CR. Survival for all patients in the protocol is favourable compared with conventional therapy and is particularly encouraging following PBSCT for alphaIFN non-responsive patients. Patients not responding to alphaIFN can be induced into Ph-negativity with PBSCT but this may not always be sustainable. There seems to be no obvious disadvantage in harvesting stem cells after prior exposure to alphaIFN, providing an adequate alphaIFN-free rest period is used.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Interferon-alfa/uso terapêutico , Leucemia Mieloide de Fase Crônica/terapia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bussulfano/administração & dosagem , Terapia Combinada , Ciclofosfamida/administração & dosagem , Citarabina/administração & dosagem , Feminino , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Mobilização de Células-Tronco Hematopoéticas , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Células-Tronco Hematopoéticas/ultraestrutura , Humanos , Idarubicina/administração & dosagem , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Leucemia Mieloide de Fase Crônica/genética , Masculino , Pessoa de Meia-Idade , Cromossomo Filadélfia , Estudos Prospectivos , Taxa de Sobrevida , Resultado do Tratamento
19.
Hematology ; 5(1): 27-39, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11399599

RESUMO

Myeloma accounts for 1% of all malignancies and is characterised by the malignant expansion of plasma cells. It is essentially incurable with a median survival of 6 months untreated. Typically disseminated at presentation, myeloma requires systemic therapy, in those patients with advanced or progressive disease. Of single agent therapies, oral mephalan remains the gold standard, either alone or in combination with steroids. 40% will respond with an increase in median survival from under 1 year to around 36 months. Combination chemotherapy produces an advantage in remission induction but no clear benefit for either survival or remission duration has been shown over standard melphalan and prednisolone. Significant melphalan dose escalation produces increased response rates and increased complete remission rates, however at the expense of increased toxicity. This has been ameliorated to an extent using stem cell support, however, although autografting may be superior to conventional chemotherapy it is not a curative treatment and modifications such as purging or tandem procedures remain to be fully evaluated. Allogeneic transplantation is only an option in a tiny minority of patients and has a high treatment-related mortality. Interferon alpha may improve the relapse free survival but has little effect on overall survival as the majority of patients will relapse. Experimental approaches, such as P-gp inhibition or thalidomide, are appropriate in this poor prognosis group. In many patients palliative care remains the only therapeutic option and close attention should be therefore paid to the prevention and treatment of renal failure, anaemia, infection, hypercalcaemia and bone disease.

20.
Br J Haematol ; 107(4): 861-9, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10606895

RESUMO

Cells of solid tumours tend to rely on glycolysis for energy. On the other hand, increased glycolysis in solid tumour cells expressing the multidrug resistance protein MDR-1 has been associated with increased malignancy in tumours. We have previously shown that cells of the MDR-1-positive CEM/VLB100 leukaemic cell line have increased mitochondrial electron transport chain (mtETC) activity compared with parental CEM cells. In the present study we used infrared (IR) spectroscopy to demonstrate that the mitochondrial DNA (mtDNA) content in the CEM/VLB100 cell line was significantly increased compared to that in the parental CEM cells. The increase in mtDNA was not accompanied by an increase in mitochondrial protein as both lipid and protein levels were decreased in CEM/VLB100 mitochondria. The ATP content was similar in these two cell lines. However, the ATP-dependent membrane efflux pump function in CEM/VLB100 cells was significantly reduced when mitochondrial ATP synthesis was inhibited by oligomycin, a specific inhibitor of mitochondrial F0F1-ATPase. Proliferation of CEM/VLB100 cells was significantly decreased compared to parental CEM cells, and was independent of p53 expression. Thus, we conclude that: (1) IR spectroscopy is a potential powerful technique for detecting mtDNA, protein and lipid contents simultaneously; (2) leukaemic cells mainly rely on mtDNA for energy; (3) increased expression of an ATP-dependent membrane efflux pump such as Pgp may up-regulate ATP generation and mtDNA content. These metabolic perturbations may exist merely to serve the efflux pump and do not result in an increase in leukaemic cell proliferation. In addition, the associated reduction in mitochondrial lipid and protein may contribute to sensitize the cells to cytochrome c release.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , DNA Mitocondrial/metabolismo , Leucemia/metabolismo , Divisão Celular/fisiologia , Resistência a Múltiplos Medicamentos , Humanos , Leucemia/patologia , Células Tumorais Cultivadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...