Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Ann Hematol ; 93(1): 129-39, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23892921

RESUMO

Lenalidomide and dexamethasone (RD) is a standard of care for relapsed/refractory multiple myeloma (RRMM), but there is limited published data on its efficacy and safety in the "real world" (RW), according to the International Society of Pharmacoeconomics and Outcomes Research definition. We studied 212 RRMM patients who received RD in RW. Objective response (≥PR (partial response)) rate was 77.4 % (complete response (CR), 20.2 %). Median time to first and best response was 2 and 5 months, respectively. Median time to CR when RD was given as 2nd or >2(nd)-line treatment at 4 and 11 months, respectively. Quality of response was independent of previous lines of therapies or previous exposure to thalidomide or bortezomib. Median duration of response was 34.4 months, and it was higher in patients who received RD until progression (not reached versus 19 months, p < 0.001). Improvement of humoral immunity occurred in 60 % of responders (p < 0.001) and in the majority of patients who achieved stable disease. Adverse events were reported in 68.9 % of patients (myelosuppression in 49.4 %) and 12.7 % of patients needed hospitalization. Peripheral neuropathy was observed only in 2.5 % of patients and deep vein thrombosis in 5.7 %. Dose reductions were needed in 31 % of patients and permanent discontinuation in 38.9 %. Median time to treatment discontinuation was 16.8 months. Performance status (PS) and initial lenalidomide dose predicted for treatment discontinuation. Extra-medullary relapses occurred in 3.8 % of patients. Our study confirms that RD is effective and safe in RRMM in the RW; it produces durable responses especially in patients who continue on treatment till progression and improves humoral immunity even in patients with stable disease.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Idoso , Anticoagulantes/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Terapia Combinada , Dexametasona/administração & dosagem , Dexametasona/efeitos adversos , Toxidermias/etiologia , Avaliação de Medicamentos , Feminino , Seguimentos , Gastroenteropatias/induzido quimicamente , Grécia , Doenças Hematológicas/induzido quimicamente , Humanos , Lenalidomida , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/genética , Mieloma Múltiplo/cirurgia , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Modelos de Riscos Proporcionais , Recidiva , Indução de Remissão , Estudos Retrospectivos , Terapia de Salvação , Talidomida/administração & dosagem , Talidomida/efeitos adversos , Talidomida/análogos & derivados , Resultado do Tratamento , Trombose Venosa/induzido quimicamente , Trombose Venosa/prevenção & controle
2.
Acta Haematol ; 130(1): 27-33, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23392079

RESUMO

BACKGROUND: A number of cytokines secreted from the bone marrow stromal cells and circulating hormones related to bone, adipose tissue and glucose metabolism might be involved in the pathogenesis of myelodysplastic syndromes (MDS). METHODS: Serum levels of cytokines related to the metabolism of bone tissue [osteocalcin and parathyroid hormone (PTH)], adipose tissue (adiponectin, leptin and ghrelin) and glucose [insulin and insulin-like growth factor-1 (IGF-1)] were determined in 72 patients suffering from MDS, mostly of the low-risk group according to FAB classification, and 41 healthy individuals (controls). RESULTS: Adiponectin and osteocalcin serum levels were significantly elevated in the MDS patients. Leptin, insulin and IGF-1 serum levels were reduced. No difference was found in the serum levels of PTH and ghrelin. Leptin levels were reversibly associated with patient blast count. CONCLUSION: Increased serum levels of adiponectin and low levels of IGF-1 in MDS patients may counterbalance the increased rate of apoptosis in the pool of hematopoietic progenitors. Osteocalcin secreted by osteoblasts regulates the renewal and proliferation of hematopoietic stem cells. Hormones and cytokines either secreted by the cells of the bone marrow stroma or transferred by the microcirculation act on hematopoietic progenitors and may regulate their differentiation, apoptosis and proliferation rate in MDS.


Assuntos
Medula Óssea/patologia , Citocinas/sangue , Hormônios/sangue , Síndromes Mielodisplásicas/metabolismo , Síndromes Mielodisplásicas/patologia , Adiponectina/sangue , Idoso , Apoptose/fisiologia , Glicemia/metabolismo , Medula Óssea/metabolismo , Diferenciação Celular/fisiologia , Proliferação de Células , Feminino , Grelina/sangue , Células-Tronco Hematopoéticas/patologia , Humanos , Insulina/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Leptina/sangue , Masculino , Síndromes Mielodisplásicas/epidemiologia , Osteoblastos/patologia , Osteocalcina/sangue , Hormônio Paratireóideo/sangue , Fatores de Risco
3.
J Radiat Res ; 53(5): 672-85, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22843358

RESUMO

Radiation exerts direct as well as indirect effects on DNA through the generation of reactive oxygen species (ROS). Irradiated hematopoietic progenitor cells (HPCs) experience DNA strand breaks, favoring genetic instability, due to ROS generation. Our aim was to study the effect of a range of radiation doses in HPCs and the possible protective mechanisms activated by insulin-like growth factor-1 (IGF-1). ROS generation was evaluated, in the presence or absence of IGF-1 in liquid cultures of human HPCs-CD34(+) irradiated with 1-, 2- and 5-Gy X-rays, using a flow cytometry assay. Manganese superoxide dismutase (MnSOD) expression was studied by western blot analysis and visualized by an immunofluorescence assay. Apoptosis was estimated using the following assays: Annexin-V assay, DNA degradation assay, BCL-2/BAX mRNA and protein levels and caspase-9 protein immunofluorescence visualization. Viability and clonogenic potential were studied in irradiated HPCs. The generation of superoxide anion radicals at an early and a late time point was increased, while the hydrogen peroxide generation at a late time point was stable. IGF-1 presence further enhanced the radiation-induced increase of MnSOD at 24 h post irradiation. IGF-1 inhibited the mitochondria-mediated pathway of apoptosis by regulating the m-RNA and protein expression of BAX, BCL-2 and the BCL-2/BAX ratio and by decreasing caspase-9 protein expression. IGF-1 presence in culture media of irradiated cells restored the clonogenic capacity and the viability of HPCs as well. In conclusion, IGF-1 protects HPCs-CD34(+) from radiation effects, by eliminating the oxidative microenvironment through the enhancement of MnSOD activation and by regulating the mitochondria-mediated pathway of apoptosis.


Assuntos
Células-Tronco Hematopoéticas/efeitos da radiação , Antígenos CD34/metabolismo , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Fragmentação do DNA/efeitos dos fármacos , Fragmentação do DNA/efeitos da radiação , Relação Dose-Resposta à Radiação , Genes bcl-2/efeitos dos fármacos , Genes bcl-2/efeitos da radiação , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Humanos , Técnicas In Vitro , Fator de Crescimento Insulin-Like I/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Superóxido Dismutase/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
4.
Acta Haematol ; 128(1): 39-46, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22614729

RESUMO

BACKGROUND/AIMS: The degradation of mRNA is a key process in the control of gene expression correlated to anomalous cell proliferation. The rate-limiting step of mRNA degradation is the removal of the poly(A) tail by deadenylases. However, studies on deadenylase expression in cancer are limited. Herein, we analyzed the expression of several deadenylases from acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). METHODS: Clinical samples from patients diagnosed with ALL and AML were the source of leukemic cells. Extracts from leukemic and control cells were analyzed for deadenylase mRNA levels using qRT-PCR, and the protein levels of PARN and CNOT7 deadenylases using immunoblotting. RESULTS: RT-PCR analysis revealed altered expression for CNOT6, CNOT6L, CNOT7 and PARN deadenylases. The most significant alterations were observed for PARN and CNOT7 mRNA levels, which also reflect on the cognate protein level. Further analysis revealed that a significant amount of PARN is phosphorylated in ALL. CONCLUSIONS: We show that the expression of several deadenylases in acute leukemias is altered. The increase of PARN expression and the alteration of its phosphorylation status indicate important regulatory events. These data suggest that the role of deadenylases as auxiliary biomarkers and therapeutic targets should be meticulously investigated.


Assuntos
Biomarcadores/metabolismo , Exorribonucleases/genética , Regulação Neoplásica da Expressão Gênica , Leucemia Mieloide Aguda/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Ribonucleases/genética , Idoso , Exorribonucleases/metabolismo , Feminino , Humanos , Leucemia Mieloide Aguda/enzimologia , Masculino , Pessoa de Meia-Idade , Fosforilação , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , RNA Mensageiro/metabolismo , Proteínas Repressoras , Ribonucleases/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
Crit Rev Oncol Hematol ; 83(1): 59-70, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22321726

RESUMO

Compared with solid tumor patients, those with hematological malignancies are at particular risk of chemotherapy-induced nausea and vomiting (CINV) because of their young age, exposure to highly-emetogenic induction, consolidation and salvage regimens, the high-dose conditioning regimens used before stem cell transplantation (SCT), and the heavy psychological burden of such treatments. In the absence of prophylaxis, around 75% of patients undergoing SCT experience delayed CINV. With first-generation 5-HT(3) receptor antagonists, only about 20% are completely protected from nausea and vomiting, and this frequent and debilitating adverse event has not been fully addressed. In contrast to solid tumors, there are no internationally agreed guidelines for the prevention and treatment of CINV in hematological malignancies. Work on a consensus is urgently required. The second-generation 5-HT(3) antagonist palonosetron is highly effective in preventing CINV in patients with solid tumors. The extended half-life of this agent and its mechanisms of action including allosteric binding, positive cooperativity and 5-HT(3) receptor internalization, may make it particularly effective in controlling delayed CINV. Although controlled comparisons against first-generation 5HT(3) agents have not yet been conducted in the setting of SCT, available evidence suggests that palonosetron may prove beneficial in preventing CINV in high risk patients with hematological malignancies.


Assuntos
Antieméticos/uso terapêutico , Antineoplásicos/efeitos adversos , Isoquinolinas/uso terapêutico , Náusea/tratamento farmacológico , Quinuclidinas/uso terapêutico , Antagonistas do Receptor 5-HT3 de Serotonina/uso terapêutico , Condicionamento Pré-Transplante/efeitos adversos , Vômito/tratamento farmacológico , Antieméticos/administração & dosagem , Antieméticos/farmacocinética , Antineoplásicos/administração & dosagem , Ensaios Clínicos Fase III como Assunto , Meia-Vida , Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas , Humanos , Isoquinolinas/administração & dosagem , Isoquinolinas/farmacocinética , Náusea/etiologia , Náusea/prevenção & controle , Palonossetrom , Quinuclidinas/administração & dosagem , Quinuclidinas/farmacocinética , Receptores 5-HT3 de Serotonina/metabolismo , Terapia de Salvação , Antagonistas do Receptor 5-HT3 de Serotonina/administração & dosagem , Antagonistas do Receptor 5-HT3 de Serotonina/farmacocinética , Transplante de Células-Tronco , Vômito/etiologia , Vômito/prevenção & controle
7.
BMC Nephrol ; 12: 33, 2011 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-21729272

RESUMO

BACKGROUND: Although renal involvement in advanced haematological malignancies is common, glomerulonephritis associated with lymphoproliferative disorders is rare, and the related pathogenetic mechanisms are still poorly understood. We present a rare case of chronic lymphocytic leukaemia(CLL)-associated focal segmental glomerulosclerosis with nephrotic-range proteinuria. CASE PRESENTATION: A 53-year-old Caucasian man, previously healthy, with no history of hypertension, alcohol use or smoking presented with rapid weight gain, massive peripheral oedema, and hypertension. Laboratory findings included a white blood cell count of 49,800 cells/mm3 with an absolute lymphocyte count of 47,000 cells/mm3, serum albumin of 2.3 g/dL, urea 65 mg/dL, and creatinine 1.5 mg/dL. A 24-hour urine collection contained 7.1 g protein and significant haematuria. A peripheral blood smear showed mature lymphocytosis and smudge cells. Diagnostic imaging showed mild paraaortic lymphadenopathy with no renal abnormalities. Bone marrow aspiration and trephine biopsy showed diffuse and focal infiltration with B-CLL lymphocytes. Percutaneous renal biopsy revealed total sclerosis in 3/21(14%) of the glomeruli and focal and segmental solidification and sclerosis in 4/21 (19%) glomeruli. A regimen of fludarabine, cyclophosphamide and rituximab was successful in inducing remission of the CLL and clinical resolution of the nephritic-range proteinuria. CONCLUSIONS: A multidisciplinary approach to monitor both the malignancy and the glomerular lesions is crucial for the optimal management of paraneoplastic glomerulonephritis. Although chemotherapy with fludarabine, cyclophosphamide and rituximab successfully treated CLL-associated nephrotic syndrome in our patient, further studies are required to confirm efficacy in this setting.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Glomerulosclerose Segmentar e Focal/diagnóstico , Glomerulosclerose Segmentar e Focal/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/diagnóstico , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Anticorpos Monoclonais Murinos/administração & dosagem , Antineoplásicos/administração & dosagem , Ciclofosfamida/administração & dosagem , Glomerulosclerose Segmentar e Focal/complicações , Humanos , Imunossupressores/administração & dosagem , Leucemia Linfocítica Crônica de Células B/complicações , Masculino , Pessoa de Meia-Idade , Agonistas Mieloablativos/administração & dosagem , Rituximab , Vidarabina/administração & dosagem , Vidarabina/análogos & derivados
8.
Clin Immunol ; 139(2): 155-63, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21342791

RESUMO

Tyrosine-kinase inhibitors are very effective in patients with CML, but in most cases the disease relapses after their discontinuation. As a result, novel approaches should be considered, such as anti-survivin treatment or anti-survivin-based immunotherapy. To gain insight into the roles of survivin isoform expression and specific CD8(+) T cells in CML, we investigated 51 patients at different stages, both at diagnosis and during treatment. We demonstrated that (i) patients at advanced-stage displayed an increased expression of the standard-survivin form along with a significant decrease of survivin-2B and -ΔEx3 levels, (ii) patients in chronic phase with higher expression of the standard-survivin exhibited a 3.5-fold increased probability not to achieve an optimal response to imatinib (p=0.048), (iii) responders displayed a significant up-regulation of all survivin isoforms in bone marrow, and (iv) anti-survivin CD8(+) T cells were undetectable both at diagnosis and during treatment. Accordingly, our results question the validity of immunotherapeutic approaches targeting survivin in CML.


Assuntos
Progressão da Doença , Resistencia a Medicamentos Antineoplásicos/fisiologia , Proteínas Inibidoras de Apoptose/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico , Linfócitos T Citotóxicos/imunologia , Adulto , Idoso , Antineoplásicos/uso terapêutico , Benzamidas , Células Sanguíneas/metabolismo , Células da Medula Óssea/imunologia , Células da Medula Óssea/metabolismo , Epitopos de Linfócito T/imunologia , Feminino , Proteínas de Fusão bcr-abl/genética , Expressão Gênica/genética , Humanos , Mesilato de Imatinib , Proteínas Inibidoras de Apoptose/genética , Proteínas Inibidoras de Apoptose/imunologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos/imunologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/imunologia , Isoformas de Proteínas/metabolismo , Survivina , Resultado do Tratamento , Adulto Jovem
9.
Ann Nucl Med ; 24(9): 639-47, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20799079

RESUMO

OBJECTIVE: Previous studies have demonstrated the feasibility of targeting lymphoma lesions with somatostatin receptor binding agents, mainly with In-111-pentetreotide. In the present work another somatostatin analog, Tc-99m depreotide, is investigated. METHODS: One-hundred and six patients, 47 with Hodgkin's (HL) and 59 with various types of non-Hodgkin's lymphoma (NHL), were imaged with both Tc-99m depreotide and Ga-67 citrate. Planar whole-body and single photon emission tomography/low resolution computerized tomography (SPECT/CT) images were obtained. A total of 142 examinations were undertaken at different phases of the disease. Depreotide and gallium findings were compared visually and semi-quantitatively, with reference to the results of conventional work-up and the patients' follow-up data. RESULTS: In most HL, intermediate- and low-grade B-cell, as well as in T-cell NHL, depreotide depicted more lesions than Ga-67 and/or exhibited higher tumor uptake. The opposite was true in aggressive B-cell NHL. However, there were notable exceptions in all lymphoma subtypes. During initial staging, 93.3% of affected lymph nodes above the diaphragm, 100% of inguinal nodes and all cases with splenic infiltration were detected by depreotide. On the basis of depreotide findings, 32% of patients with early-stage HL were upstaged. However, advanced HL and NHL cases were frequently downstaged, due to low sensitivity for abdominal lymph node (22.7%), liver (45.5%) and bone marrow involvement (36.4%). Post-therapy, depreotide detected 94.7% of cases with refractory disease or recurrence. Its overall specificity was moderate (57.1%). Rebound thymic hyperplasia, various inflammatory processes and sites of unspecific uptake were the commonest causes of false positive findings. The combination of depreotide and gallium enhanced sensitivity (100%), while various false positive results of either agent could be avoided. CONCLUSION: Except perhaps for early-stage HL, Tc-99m depreotide as a stand-alone imaging modality has limited value for the initial staging of lymphomas. Post-therapy, however, depreotide scintigraphy seems useful in the evaluation of certain anatomic areas, particularly in non-aggressive lymphoma types. The combination with Ga-67 potentially enhances sensitivity and specificity. If fluorodeoxyglucose positron emission tomography is not available or in case of certain indolent lymphoma types, Tc-99m depreotide may have a role as an adjunct to conventional imaging procedures.


Assuntos
Citratos , Gálio , Linfoma/diagnóstico , Compostos de Organotecnécio , Somatostatina/análogos & derivados , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Transporte Biológico , Feminino , Humanos , Linfonodos/diagnóstico por imagem , Linfonodos/metabolismo , Linfoma/metabolismo , Linfoma/patologia , Linfoma/terapia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Compostos de Organotecnécio/farmacocinética , Recidiva , Somatostatina/farmacocinética , Adulto Jovem
10.
Acta Derm Venereol ; 89(2): 134-9, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19325996

RESUMO

The aim of this study was to determine whether imiquimod, a Toll-like receptor-7/8 agonist, in addition to its well-known topical action on the cutaneous immune response, might also induce alterations in the peripheral blood lymphocytes. A 62.5 mg quantity of imiquimod (5% cream) was applied topically under occlusion once daily every second day for 3 weeks to the skin of 10 healthy volunteers, age range 30-57 years. Ten sex- and age-matched healthy controls applied corresponding quantities of the vehicle under occlusion. Before, and one and 3 weeks after the start of treatment, peripheral blood lymphocyte subpopulations were measured by flow cytometry. Statistically significant alterations in the percentage or absolute numbers of peripheral blood lymphocyte subpopulations were found in the imiquimod-treated group compared with the control group. These alterations indicate for the first time that topical application of imiquimod induces alterations in peripheral blood lymphocyte subsets in healthy individuals, which may be of importance in the immunotherapy of neoplastic and infectious disorders and should be taken into careful consideration in patients who are treated with imiquimod.


Assuntos
Adjuvantes Imunológicos/farmacologia , Aminoquinolinas/farmacologia , Linfócitos/efeitos dos fármacos , Adjuvantes Imunológicos/administração & dosagem , Administração Cutânea , Adulto , Aminoquinolinas/administração & dosagem , Antígenos CD/análise , Antígenos HLA-DR/análise , Humanos , Imiquimode , Subpopulações de Linfócitos/efeitos dos fármacos , Linfócitos/imunologia , Masculino , Pessoa de Meia-Idade , Receptor 7 Toll-Like/agonistas , Receptor 8 Toll-Like/agonistas
11.
BMC Blood Disord ; 9: 1, 2009 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-19187542

RESUMO

BACKGROUND: Primary eosinophlia associated with the FIP1L1-PDGFRA rearrangement represents a subset of chronic eosinophilic leukaemia (CEL) and affected patients are very sensitive to imatinib treatment. This study was undertaken in order to examine the prevalence and the associated clinicopathologic and genetic features of FIP1L1-PDGFRA rearrangement in a cohort of 15 adult patients presenting with profound eosinophilia (> 1.5 x 109/L). METHODS: Reverse transcriptase-polymerase chain reaction (RT-PCR) was used for the detection of FIP1L1-PDGFRA rearrangement and the results confirmed by direct sequencing. C-KIT-D816V mutation was analysed retrospectively by PCR and restriction-fragment-length-polymorphism (PCR-RFLP), in all cases with primary eosinophilia. RESULTS: Two male patients with splenomegaly carried the FIP1L1-PDGFRA rearrangement, whilst 2 others were ultimately classified as suffering from idiopathic hypereosinophlic syndrome (HES) and one from systemic mastocytosis. These patients were negative for the C-KIT-D816V mutation and received imatinib (100-400 mg daily). Patients with CEL and HES responded to imatinib and remained in complete haematological, clinical and molecular (for carriers of FIP1L1-PDGFRA rearrangement) remission for a median of 28.2 months (range: 11-54), whilst the patient with systemic mastocytosis did not respond. Interestingly, in both patients with FIP1L1-PDGFRA rearrangement, the breakpoints into PDGFRA were located within exon 12 and fused with exons 8 and 8a of FIP1L1, respectively. CONCLUSION: An early diagnosis of FIPIL1-PDGFRA-positive CEL and imatinib treatment offer to the affected patients an excellent clinical therapeutic result, avoiding undesirable morbidity. Moreover, although the molecular mechanisms underlying disease pathogenesis remain to be determined, imatinib can be effective in patients with idiopathic HES.

12.
Anticancer Res ; 29(12): 5077-82, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20044619

RESUMO

BACKGROUND: Panitumumab, a fully-human monoclonal antibody raised against epidermal growth factor receptor (EGFR), has been approved by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMEA) for the treatment of patients with EGFR-expressing metastatic colorectal carcinoma (mCRC) after failure of standard chemotherapy. Additionally, the guideline of the EMEA includes the use of panitumumab in patients with wild-type KRAS. The goal of the current study was to evaluate the effect of panitumumab on colon cancer cells, proliferation, apoptosis, necrosis, cell cycle arrest and autophagy. The effect of panitumumab on the redox status of the cells was also studied. MATERIALS AND METHODS: The cell lines Caco-2, DLD-1 and HT-29 which differ in their expression of EGFR and HER-2 were used. Cell proliferation and apoptosis/necrosis were measured by methyl tetrazolium (MTT) assay and annexin V/propidium iodide assay, respectively. Cell cycle arrest was estimated by propidium iodide assay and autophagy was detected using Western blot analysis. Spectrophotometrical quantification of glutathione (GSH) levels and an analysis of KRAS sequence were applied. RESULTS: Panitumumab reduced proliferation only in the DLD-1 cells despite the mutated KRAS in this cell line. However, panitumumab did not affect DLD-1 cell apoptosis, necrosis or cell cycle progression. Interestingly, immunoblotting analysis revealed that panitumumab increased protein levels of beclin-1, a marker of autophagy. In addition, an increase in the GSH level was noted following panitumumab treatment reflecting an imbalance in the redox status of the cells. CONCLUSION: Panitumumab affects colon cancer cell proliferation independently of KRAS mutations and EGFR protein levels, possibly through the induction of autophagy.


Assuntos
Anticorpos Monoclonais/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Autofagia , DNA de Neoplasias/genética , Glutationa/metabolismo , Humanos , Immunoblotting , Mutação , Oxirredução , Panitumumabe , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas p21(ras) , Células Tumorais Cultivadas , Proteínas ras/genética
13.
J Radiat Res ; 49(1): 41-7, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18049035

RESUMO

PURPOSE: Radiation induces apoptosis as a result of damage to cellular DNA and RNA. The aim of our work was to study the effect of radiation on rat bone marrow cells (as a neighboring tissue) in the context of a model of experimental radiation enteritis in rats. The effect of systematic administration in irradiated animals of r-IGF-1 and GH was also studied. MATERIALS AND METHODS: Wistar type, normal rats, were divided in 4 groups. One control group and the other 3 groups were irradiated in the abdomen. The measured scattered irradiation in the femur ranged from 16.5 to 47.3 cGy. In 2 groups of irradiated animals, rIGF-1 (0.1 microg/g of body weight twice/d) and rGH (0.25 microg/g of body weight /d) were administered. Bone marrow cells were harvested from both femurs. DNA and RNA were analyzed in specific gels. The m-RNA was hybridized for c-fos proto-oncogene expression. RESULTS: The calculated low dose of radiation that affected the femurs of the animals induced reduction in bone marrow cell numbers and endonuclease activation manifested by subsequent fragmentation of DNA and RNA. This phenomenon was reversed by rGH and rIGF-1 administration. The c-fos proto-oncogene expression was upregulated by irradiation. CONCLUSION: These observations indicate that scattered low dose radiation is capable of initiating apoptosis in rat bone marrow cells and rGH and rIGF-1 administration reverse this process.


Assuntos
Apoptose , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/efeitos da radiação , Fêmur/efeitos da radiação , Fator de Crescimento Insulin-Like I/farmacologia , Animais , Contagem de Células , Proliferação de Células , Fragmentação do DNA , Masculino , Proteínas Proto-Oncogênicas c-fos/metabolismo , RNA Ribossômico/metabolismo , Ratos , Ratos Wistar
15.
Br J Haematol ; 124(1): 97-105, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14675414

RESUMO

Immune dysfunction, which leads to the suppression of haemopoiesis by cytokines that are secreted by activated T lymphocytes, is considered to play a key role in the pathogenesis of acquired aplastic anaemia (AAA). We investigated the intracytoplasmic expression of type-1 [interferon gamma (IFN-gamma), interleukin (IL)-2] and type-2 (IL-4, IL-10) cytokines in CD4+ and CD8+ T cells before and after in vitro activation in 16 patients with AAA and 17 normal controls. Untreated or refractory patients had a significantly higher proportion of unstimulated CD4+ and CD8+ T cells that produced IFN-gamma and IL-2 whereas the IL-4 and IL-10 producing T cells did not differ from that of controls, resulting in a shift of IFN-gamma/IL-4 ratio towards a type-1 response. Patients in remission had also increased proportion of IFN-gamma-producing unstimulated CD4+ and CD8+ cells, with a parallel rise of IL-4- and IL-10-producing cells and normal IFN-gamma/IL-4 ratio. These data indicate that, in newly diagnosed and refractory patients with AAA, CD4+ cells are polarized towards a type-1 response that in turn leads to activation of cytotoxic CD8+ cells and finally to haemopoietic stem cell destruction. The type-1 response persists in patients in remission although this effect is compensated by the increase of IL-4 and IL-10 production.


Assuntos
Anemia Aplástica/imunologia , Interferon gama/metabolismo , Interleucinas/metabolismo , Células Th1/imunologia , Células Th2/imunologia , Adulto , Idoso , Citoplasma/imunologia , Feminino , Humanos , Imunofenotipagem , Interleucina-10/metabolismo , Interleucina-2/metabolismo , Interleucina-4/metabolismo , Masculino , Pessoa de Meia-Idade , Subpopulações de Linfócitos T/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...