RESUMO
PURPOSE: Pericardial effusion (PE) is a potentially life-threatening complication following hematopoietic stem cell transplantation (HCT). A higher incidence of early-onset PE, unrelated to graft-versus-host disease, before day 100 after HCT has been reported in pediatric patients, but the pathogenic mechanism is poorly understood. Aiming to determine the pathogenesis of early-onset PE in pediatric patients, we analyzed the cytokine concentration and cell population in the pericardial fluid of four pediatric patients with PE. METHODS: Between January 2009 and December 2015, four patients requiring pericardiocentesis for clinically significant PE were identified in 60 patients. We evaluated the interleukin-6 (IL-6), interferon-γ, IL-1ß, and tumor necrosis factor-α levels in PE. Two patients were available for analysis with intracellular cytokine flow cytometry and a chimerism assay. RESULTS: All patients showed the accumulation of pericardial macrophages and high concentrations of IL-6 in PE. Notably, the accumulated pericardial macrophages were CD163+ CD15+ CD14+ cells of host origin that produced IL-6. CONCLUSION: These IL-6-producing tissue-resident macrophages may be key players in the pathogenesis of early-onset PE.
Assuntos
Doenças Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Interleucina-6/metabolismo , Macrófagos/metabolismo , Derrame Pericárdico/patologia , Idade de Início , Pré-Escolar , Feminino , Humanos , Lactente , Macrófagos/patologia , Masculino , Derrame Pericárdico/etiologia , Derrame Pericárdico/metabolismo , Prognóstico , Fatores de RiscoRESUMO
Epstein-Barr virus (EBV) has many strains; however, it remains unclear whether a causal relationship exists between different regions and viral genetic variants in healthy persons. This study was designed to examine the relationship between EBV strains in tonsils and adenoids and peripheral blood lymphocytes of the same individuals using different measurements of EBV strain polymorphism. This study examined whether EBV contains two or three copies of a tandem repeat sequence in the first intron of the BZLF-1 gene. The genotype of the virus from P3HR-1, designated Z*, yielded a 415-bp product, and this was distinguished from the smaller, 386-bp product obtained with the B95-8 virus, designated the Z genotype. Simultaneous sequence infections with Z and Z* genotypes were also detected in one of the tonsils examined, suggesting that more than one strain or variant of EBV genotype may be present in a specimen from the same subject. Co-infection with Z and Z* was recognized in two subjects, so variation of the EBV gene may be seen in at least two different strains of EBV. It was seen that Z and Z* strain-infected cells are constantly in flux through lymph nodes and/or the blood stream in healthy persons; therefore, these results indicated that EBV genome variants probably show no specific tissue distribution.
Assuntos
Infecções por Vírus Epstein-Barr/virologia , Variação Genética , Herpesvirus Humano 4/classificação , Herpesvirus Humano 4/genética , Transativadores/genética , Tonsila Faríngea/virologia , Coinfecção/virologia , Voluntários Saudáveis , Herpesvirus Humano 4/isolamento & purificação , Humanos , Íntrons , Linfócitos/virologia , Tonsila Palatina/virologiaRESUMO
Adult T-cell leukemia (ATL) is a T-cell malignancy etiologically associated with human T-cell leukemia virus type 1 (HTLV-1). Twist, a highly conserved basic helix-loop-helix transcription factor, is a newly identified oncogene. However, there are no reports on Twist expression in ATL. To define the role of Twist in leukemogenesis of ATL, we examined its expression in T-cell lines and PBMC. HTLV-1-infected T-cell lines and ATL cells expressed high levels of Twist compared with uninfected T-cell lines and normal PBMC. Immunohistochemistry showed immunostaining for Twist in ATL cells in ATL lymph nodes and skin lesions. Infection of normal PBMC with HTLV-1 induced Twist expression. Induction of the viral protein Tax in a human T-cell line led to upregulation of Twist. Tax-induced Twist expression involved the NF-kappaB and CREB signaling pathways. Twist augmented Tax-mediated HTLV-1 LTR and NF-kappaB activation. Short interfering RNA against Twist inhibited cell growth of HTLV-1-infected T-cell lines and downregulation of Twist expression in an HTLV-1-infected T-cell line inhibited the expression of Akt1, interleukin-2 receptor alpha chain, and Tax as well as the known target genes of Twist, YB-1 and Akt2. In conclusion, the results suggest that Tax-induced induction of Twist contributes to leukemogenesis of ATL.
RESUMO
OBJECTIVE: To investigate whether the long-term presence of a patulous Eustachian tube (PET) is associated with sensorineural hearing loss (SNHL). STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Ears (nâ=â100) were classified into two groups based on duration of PET symptom(s), i.e., Short (≤3 mo; nâ=â47 ears) and Long (≥48 mo; nâ=â53 ears). Contralateral ears without PET (nâ=â28 ears) were classified as the Contralateral group. MAIN OUTCOME MEASURES: We used ISO 7029 to calculate the hearing thresholds of an age- and sex-matched population at a given frequency. Hearing loss was defined as >25% of these calculated values. RESULTS: At 4âkHz, the Long PET group showed a higher prevalence of hearing loss (47%) at 4âkHz than did the Contralateral (21%) and Short PET (19%) groups (pâ=â0.0280 and 0.0043, respectively). Ears with breathing autophony or a sonotubometric low probe tone level showed a higher prevalence of hearing loss at 4âkHz than those without this symptom or with a high probe tone level (pâ=â0.0329 or 0.0103, respectively). At low frequencies, ≥89% of the ears in all groups showed mild hearing loss. CONCLUSION: Chronic PET was associated with SNHL at 4âkHz. PET patients showed low-frequency hearing loss regardless of disease duration. Further studies are needed to better understand the pathophysiology of SNHL in patients with PET.
Assuntos
Tuba Auditiva , Perda Auditiva Neurossensorial , Otite Média , Tuba Auditiva/diagnóstico por imagem , Audição , Perda Auditiva Neurossensorial/diagnóstico por imagem , Perda Auditiva Neurossensorial/epidemiologia , Perda Auditiva Neurossensorial/etiologia , Humanos , Estudos RetrospectivosRESUMO
BACKGROUND: Cisplatin plus fluorouracil is widely used for the treatment of head and neck cancer. However, the cisplatin plus fluorouracil regimen necessitates hospitalization. Therefore, we planned to develop a new regimen that can be administered on an outpatient basis and performed a phase I study of S-1 + nedaplatin. METHODS: S-1 was given orally at a fixed dose for 14 days, and nedaplatin was administered intravenously on day 8 of S-1 administration. The dose of nedaplatin was increased in 10-mg/m(2) steps to find the maximum tolerated dose, depending on the appearance of dose-limiting toxicities. RESULTS: A total of 14 patients were registered. The maximum tolerated dose of nedaplatin was determined to be 90 mg/m(2). The main toxicities were neutropenia and thrombocytopenia. The response rate was 57.1%. CONCLUSION: The recommended dose of nedaplatin for a phase II study was determined to be 80 mg/m(2). We concluded that our regimen was well tolerated and that the response rate was acceptable.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Compostos Organoplatínicos/administração & dosagem , Ácido Oxônico/administração & dosagem , Tegafur/administração & dosagem , Idoso , Carcinoma/tratamento farmacológico , Carcinoma de Células Escamosas , Cisplatino/administração & dosagem , Cisplatino/uso terapêutico , Progressão da Doença , Combinação de Medicamentos , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/uso terapêutico , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Neoplasias de Células Escamosas/tratamento farmacológico , Compostos Organoplatínicos/efeitos adversos , Compostos Organoplatínicos/uso terapêutico , Ácido Oxônico/efeitos adversos , Ácido Oxônico/uso terapêutico , Carcinoma de Células Escamosas de Cabeça e Pescoço , Tegafur/efeitos adversos , Tegafur/uso terapêuticoRESUMO
Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent for adult T-cell leukemia (ATL). Aurora A, a mitotic checkpoint protein, is overexpressed in human cancer cells. The cell cycle-dependent turnover of Aurora A is regulated by E3 ubiquitin ligases such as checkpoint with fork head-associated and ring finger (CHFR). Here, we found overexpression of Aurora A protein in HTLV-1-infected T-cell lines and primary ATL cells. The expression of CHFR mRNA was reduced in these cells by abnormal methylation of CHFR promoter region. Knockdown of Aurora A using small interfering RNA suppressed the growth of HTLV-1-infected T-cell line. Transfection of Aurora A expression plasmid enhanced Tax-induced nuclear factor-kappaB (NF-kappaB) reporter activity. Transfection of CHFR expression plasmid into an HTLV-1-infected T-cell line reduced cell growth, Aurora A protein level and constitutive NF-kappaB reporter activity. Aurora kinase inhibitor suppressed the growth and survival of HTLV-1-infected T-cell lines and primary ATL cells. It also reduced constitutive NF-kappaB activity in an HTLV-1-infected T-cell line by reducing IkappaB kinase beta phosphorylation and the expression of antiapoptotic protein survivin. Our results suggested that loss of CHFR expression resulted to accumulation of Aurora A, which increased NF-kappaB activity. These findings highlight the critical role of Aurora A in HTLV-1-infected T cells, making this molecule a potentially suitable target for future therapies for ATL.
Assuntos
Proteínas de Ciclo Celular/genética , Vírus Linfotrópico T Tipo 1 Humano/fisiologia , Leucemia-Linfoma de Células T do Adulto/patologia , NF-kappa B/metabolismo , Proteínas de Neoplasias/genética , Proteínas Serina-Treonina Quinases/fisiologia , Linfócitos T/virologia , Apoptose , Aurora Quinases , Ciclo Celular , Linhagem Celular , Proliferação de Células , Sobrevivência Celular , Metilação de DNA , Humanos , Leucemia-Linfoma de Células T do Adulto/enzimologia , Proteínas de Ligação a Poli-ADP-Ribose , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Transdução de Sinais , Linfócitos T/fisiologia , Ubiquitina-Proteína LigasesRESUMO
Preservation of the larynx is the most critical factor influencing quality of life in the treatment of head and neck cancer. This clinical study focuses on laryngeal function-preserving chemoradiotherapy for locally advanced hypopharyngeal and laryngeal cancer. Thirty-two resectable cases with histologically proven squamous cell carcinoma undergoing function-preserving therapy were examined. Induction chemotherapy comprised cisplatin and 5-fluorouracil, and another cycle of chemotherapy was performed for responders. Chemoradiotherapy comprised conventional irradiation and weekly chemotherapy (nedaplatin plus docetaxel). Non-responder patients were excluded from further chemotherapy and were changed to other surgical treatment. Three patients were non-responders for induction chemotherapy, and 29 patients were treated with chemoradiotherapy. Thus, 21 out of 29 patients obtained preserved laryngeal function. Initial larynx preservation rate with these treatment strategies was 93.8%. This study provides a new concept for laryngeal function-preserving treatment that should be considered for locally advanced laryngeal and hypopharyngeal cancer.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/terapia , Neoplasias Hipofaríngeas/terapia , Neoplasias Laríngeas/terapia , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Cisplatino/administração & dosagem , Terapia Combinada , Feminino , Fluoruracila/administração & dosagem , Humanos , Neoplasias Hipofaríngeas/tratamento farmacológico , Neoplasias Hipofaríngeas/radioterapia , Neoplasias Laríngeas/tratamento farmacológico , Neoplasias Laríngeas/radioterapia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Taxa de Sobrevida , Resultado do TratamentoRESUMO
HTLV-1 (human T-cell leukaemia virus type 1) is the causative agent for ATL (adult T-cell leukaemia). HTLV-1 Tax can activate the PI3K (phosphoinositide 3-kinase)/Akt signalling pathway, which is responsible for survival of HTLV-1-infected T-cells. HIFs (hypoxia-inducible factors) are transcriptional regulators that play a central role in the response to hypoxia. Overexpression of HIF-1alpha in many cancers is associated with a poor response to treatment and increased patient mortality. Our objectives in the present study were to investigate whether HIF-1 was activated in HTLV-1-infected T-cells and to elucidate the molecular mechanisms of HIF-1 activation by focusing on the PI3K/Akt signalling pathway. We detected a potent pathway that activated HIF-1 in the HTLV-1-infected T-cells under a normal oxygen concentration. Enhanced HIF-1alpha protein expression and HIF-1 DNA-binding activity were exhibited in HTLV-1-infected T-cell lines. Knockdown of HIF-1alpha by siRNA (small interfering RNA) suppressed the growth and VEGF (vascular endothelial growth factor) expression of the HTLV-1-infected T-cell line. HIF-1 protein accumulation and transcriptional activity were enhanced by Tax, which was inhibited by dominant-negative Akt. Importantly, mutant forms of Tax that are defective in activation of the PI3K/Akt pathway failed to induce HIF-1 transcriptional activity. The PI3K inhibitor LY294002 suppressed HIF-1alpha protein expression, HIF-1 DNA-binding and HIF-1 transcriptional activity in HTLV-1-infected T-cell lines. In primary ATL cells, HIF-1alpha protein levels were strongly correlated with levels of phosphorylated Akt. The results of the present study suggest that PI3K/Akt activation induced by Tax leads to activation of HIF-1. As HIF-1 plays a major role in tumour progression, it may represent a molecular target for the development of novel ATL therapeutics.
Assuntos
Vírus Linfotrópico T Tipo 1 Humano/fisiologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Leucemia de Células T/metabolismo , Adulto , DNA/metabolismo , Ativação Enzimática , Regulação Neoplásica da Expressão Gênica , Produtos do Gene tax/farmacologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Leucemia de Células T/genética , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Ligação Proteica , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Interferente Pequeno/genética , Transdução de Sinais/efeitos dos fármacos , Células Tumorais CultivadasAssuntos
Miastenia Gravis , Neoplasias Ovarianas , Síndromes Paraneoplásicas , Humanos , Feminino , Miastenia Gravis/complicações , Miastenia Gravis/diagnóstico , Autoanticorpos , Neoplasias Ovarianas/complicações , Neoplasias Ovarianas/diagnóstico , Síndromes Paraneoplásicas/diagnóstico , Síndromes Paraneoplásicas/etiologiaRESUMO
Adult T-cell leukemia (ATL) is caused by human T-cell leukemia virus type I (HTLV-I) and remains incurable. NIK-333, a novel synthetic retinoid, prevents the recurrence of human hepatoma after surgical resection of primary tumors. We explored the effects of NIK-333 on HTLV-I-infected T-cell lines and ATL cells. NIK-333 inhibited cell proliferation, induced G1 arrest, and resulted in massive apoptosis in all tested HTLV-I-infected T-cell lines and ATL cells, whereas little effect was observed on normal peripheral blood mononuclear cells. NIK-333 treatment decreases the levels of cyclin D1, cyclin D2, cIAP2, and XIAP proteins. Further analysis showed that NIK-333 inactivated nuclear factor-kappaB in HTLV-I-infected T-cell lines. In animal studies, treatment with NIK-333 (100 mg/kg given orally every other day) produced partial inhibition of growth of tumors of a HTLV-I-infected T-cell line transplanted s.c. in severe combined immunodeficient mice. Our results indicate that NIK-333 is a potentially useful therapeutic agent for patients with ATL.
Assuntos
Infecções por HTLV-I/tratamento farmacológico , Vírus Linfotrópico T Tipo 1 Humano , Leucemia de Células T/tratamento farmacológico , Leucemia-Linfoma de Células T do Adulto/tratamento farmacológico , NF-kappa B/antagonistas & inibidores , Retinoides/uso terapêutico , Animais , Apoptose , Linhagem Celular Transformada , Linhagem Celular Tumoral , Ciclina D1/metabolismo , Ciclina D2 , Ciclinas/metabolismo , Regulação para Baixo , Feminino , Infecções por HTLV-I/virologia , Humanos , Proteínas Inibidoras de Apoptose/metabolismo , Leucemia de Células T/virologia , Leucemia-Linfoma de Células T do Adulto/virologia , Camundongos , Camundongos Endogâmicos , Transdução de Sinais , Linfócitos T/virologia , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismoRESUMO
BACKGROUND: Human T-cell leukemia virus type 1 (HTLV-1), the etiologic agent for adult T-cell leukemia (ATL), induces cytokine-independent proliferation of T-cells, associated with the acquisition of constitutive activation of Janus kinases (Jak) and signal transducers and activators of transcription (Stat) proteins. Our purposes in this study were to determine whether activation of Jak-Stat pathway is responsible for the proliferation and survival of ATL cells, and to explore mechanisms by which inhibition of Jak-Stat pathway kills ATL cells. RESULTS: Constitutive activation of Stat3 and Stat5 was observed in HTLV-1-infected T-cell lines and primary ATL cells, but not in HTLV-1-negative T-cell lines. Using AG490, a Jak-specific inhibitor, we demonstrated that the activation of Stat3 and Stat5 was mediated by the constitutive phosphorylation of Jak proteins. AG490 inhibited the growth of HTLV-1-infected T-cell lines and primary ATL cells by inducing G1 cell-cycle arrest mediated by altering the expression of cyclin D2, Cdk4, p53, p21, Pim-1 and c-Myc, and by apoptosis mediated by the reduced expression of c-IAP2, XIAP, survivin and Bcl-2. Importantly, AG490 did not inhibit the growth of normal peripheral blood mononuclear cells. CONCLUSION: Our results indicate that activation of Jak-Stat pathway is responsible for the proliferation and survival of ATL cells. Inhibition of this pathway may provide a new approach for the treatment of ATL.
Assuntos
Vírus Linfotrópico T Tipo 1 Humano/genética , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT5/metabolismo , Linfócitos T/virologia , Sequência de Bases , Linhagem Celular , Linhagem Celular Tumoral , Primers do DNA , Inibidores Enzimáticos/farmacologia , Humanos , Leucemia-Linfoma de Células T do Adulto , Fosforilação , Proteínas Tirosina Quinases/metabolismo , Fatores de Transcrição STAT/metabolismo , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT5/genética , Transdução de Sinais , Linfócitos T/enzimologia , Tirfostinas/farmacologiaRESUMO
Activation of the activator protein 1 (AP-1) plays a critical role in oncogenesis by human T-cell leukemia virus type 1 (HTLV-1), the etiologic agent of adult T-cell leukemia (ATL), and is required for maintenance of the malignant phenotype. Curcumin (diferuloylmethane), the major pigment of the spice turmeric, has anti-tumor activity; however, the effect of curcumin against ATL has not been elucidated. In this study, we examined the effects of curcumin on AP-1 activity in HTLV-1-infected T-cell lines. Curcumin suppressed the constitutive AP-1 DNA-binding and transcriptional activity in HTLV-1-infected T-cell line. Curcumin also inhibited HTLV-1 Tax-induced AP-1 transcriptional activity. JunD was detectable as a major component of the AP-1-DNA complex in HTLV-1-infected T-cell lines using the supershift assay. The expression of JunD was suppressed by curcumin treatment. Curcumin inhibited the growth of HTLV-1-infected T-cell lines by inducing cell cycle arrest followed by apoptosis. Our results suggest that suppression of the constitutively active AP-1 by curcumin is due to, at least in-part, reducing the expression of JunD by curcumin. Inhibition of AP-1 activity by curcumin may be one of the mechanisms responsible for the anti-ATL effect of curcumin. We propose that curcumin is a potentially promising compound for the treatment of ATL.
Assuntos
Curcumina/farmacologia , Inibidores Enzimáticos/farmacologia , Vírus Linfotrópico T Tipo 1 Humano/metabolismo , Leucemia-Linfoma de Células T do Adulto/metabolismo , Proteínas Proto-Oncogênicas c-jun/antagonistas & inibidores , Linfócitos T/metabolismo , Fator de Transcrição AP-1/metabolismo , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Curcumina/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Genes pX/efeitos dos fármacos , Humanos , Leucemia-Linfoma de Células T do Adulto/tratamento farmacológico , Leucemia-Linfoma de Células T do Adulto/patologia , Proteínas Proto-Oncogênicas c-jun/metabolismo , Linfócitos T/patologia , Linfócitos T/virologia , Transcrição Gênica/efeitos dos fármacosRESUMO
This report describes an unusual case of sarcomatoid carcinoma of the bladder in a 3-year-old girl. Although saving the patient's life is most essential, it is also essential to consider quality of life. The patient underwent neoadjuvant chemotherapy with gemcitabine and cisplatin for bladder preservation. The tumor considerably decreased in size. After 4 courses of chemotherapy, the patient underwent a partial cystectomy followed by postoperative irradiation with 2 courses of chemotherapy. Seventy months after the operation, she remains alive, showing complete remission with normal bladder function. Chemotherapy resulted in tumor shrinkage and allowed for bladder preservation.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma/terapia , Tratamentos com Preservação do Órgão , Neoplasias da Bexiga Urinária/terapia , Carcinoma/patologia , Quimioterapia Adjuvante , Pré-Escolar , Cisplatino/administração & dosagem , Cistectomia/métodos , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Feminino , Humanos , Terapia Neoadjuvante , Radioterapia Adjuvante , Neoplasias da Bexiga Urinária/patologia , GencitabinaRESUMO
CONTEXT: Autoimmune thyroid diseases have been reported to be associated with human T cell leukemia virus type I (HTLV-I) infection. HTLV-I proviral load is related to the development of HTLV-I-associated myelopathy/tropical spastic paraparesis and has also been shown to be elevated in the peripheral blood of HTLV-I-infected patients with uveitis, arthritis, and connective tissue disease. OBJECTIVE: The objective of the study was to evaluate the proviral load in HTLV-I-infected patients with Hashimoto's thyroiditis (HT) or Graves' disease (GD) and ascertain the ability of HTLV-I to infect thyroid cells. PATIENTS AND METHODS: A quantitative real-time PCR assay was developed to measure the proviral load of HTLV-I in peripheral blood mononuclear cells from 26 HTLV-I-infected patients with HT, eight HTLV-I-infected patients with GD, or 38 asymptomatic HTLV-I carriers. Rat FRTL-5 thyroid cells were cocultured with HTLV-I-infected T cell line MT-2 or uninfected T cell line CCRF-CEM. After coculture with T cell lines, changes in Tax and cytokine mRNA expression were studied by RT-PCR. RESULTS: HTLV-I proviral load was significantly higher in the peripheral blood of patients with HT and GD than asymptomatic HTLV-I carriers. In the peripheral blood from HTLV-I-infected patients with HT, HTLV-I proviral load did not correlate with the thyroid peroxidase antibody or thyroglobulin antibody titer. After coculture with MT-2 cells, FRTL-5 cells expressed HTLV-I-specific Tax mRNA. These cocultured FRTL-5 cells with MT-2 cells expressed IL-6 mRNA and proliferated more actively than those cocultured with CCRF-CEM cells. CONCLUSION: Our findings suggest the role of the retrovirus in the development of autoimmune thyroid diseases in HTLV-I-infected patients.
Assuntos
Doença de Graves/complicações , Infecções por HTLV-I/complicações , Tireoidite Autoimune/complicações , Adulto , Idoso , Animais , Contagem de Linfócito CD4 , Linhagem Celular , Proliferação de Células , Técnicas de Cocultura , Citocinas/biossíntese , Citocinas/genética , DNA Viral/biossíntese , DNA Viral/genética , Feminino , Infecções por HTLV-I/virologia , Humanos , Leucemia de Células T/complicações , Leucemia-Linfoma de Células T do Adulto/virologia , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Neoplásico/biossíntese , RNA Neoplásico/genética , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Carga ViralRESUMO
BACKGROUND: Human T-cell leukemia virus type 1 (HTLV-1) is associated with the development of adult T-cell leukemia (ATL). HTLV-1 encoded Tax1 oncoprotein activates the transcription of genes involved in cell growth and anti-apoptosis through the NF-kappaB pathway, and is thought to play a critical role in the pathogenesis of ATL. While Tax1 expression is usually lost or minimal in ATL cells, these cells still show high constitutive NF-kappaB activity, indicating that genetic or epigenetic changes in ATL cells induce activation independent of Tax1. The aim of this study was to identify the molecules responsible for the constitutive activation of NF-kappaB in ATL cells using a retroviral functional cloning strategy. RESULTS: Using enhanced green fluorescent protein (EGFP) expression and blasticidin-resistance as selection markers, several retroviral cDNA clones exhibiting constitutive NF-kappaB activity in Rat-1 cells, including full-length CD30, were obtained from an ATL cell line. Exogenous stable expression of CD30 in Rat-1 cells constitutively activated NF-kappaB. Elevated expression of CD30 was identified in all ATL lines examined, and primary ATL cells from a small number of patients (8 out of 66 cases). CONCLUSION: Elevated CD30 expression is considered one of the causes of constitutive NF-kappaB activation in ATL cells, and may be involved in ATL development.
Assuntos
Antígeno Ki-1/metabolismo , Leucemia-Linfoma de Células T do Adulto/metabolismo , NF-kappa B/metabolismo , Regulação para Cima , Animais , Linhagem Celular , Fibroblastos , Vírus Linfotrópico T Tipo 1 Humano/patogenicidade , Humanos , Células Jurkat , Ratos , Linfócitos T , Células Tumorais CultivadasRESUMO
Anti-resorptive bisphosphonates are used for the treatment of hypercalcaemia and bone complications associated with malignancies and osteoporosis, but also have been shown to have anti-tumour effects in various cancers. Adult T-cell leukaemia (ATL) is a fatal T-cell malignancy caused by infection with human T-cell leukaemia virus type I (HTLV-I), and remains incurable. ATL is associated with osteolytic bone lesions and hypercalcaemia, both of which are major factors in the morbidity of ATL. Thus, the search for anti-ATL agents that have both anti-tumour and anti-resorptive activity is warranted. The bisphosphonate agent, incadronate, prevented cell growth of HTLV-I-infected T-cell lines and primary ATL cells, but not of non-infected T-cell lines or normal peripheral blood mononuclear cells. Incadronate induced S-phase cell cycle arrest and apoptosis in HTLV-I-infected T-cell lines, and treatment of these cells with substrates of the mevalonate pathway blocked the incadronate-mediated growth suppression. Incadronate also prevented the prenylation of Rap1A protein. These results demonstrated that incadronate-induced growth suppression occurs by interfering with the mevalonate pathway. Importantly, treatment with incadronate reduced tumour formation from an HTLV-I-infected T-cell line when these cells were inoculated subcutaneously into severe combined immunodeficient mice. These findings suggest that incadronate could be potentially useful for the treatment of ATL.
Assuntos
Antimetabólitos/uso terapêutico , Difosfonatos/uso terapêutico , Vírus Linfotrópico T Tipo 1 Humano , Leucemia de Células T/tratamento farmacológico , Ácido Mevalônico/metabolismo , Linfócitos T/metabolismo , Idoso , Animais , Antimetabólitos/farmacologia , Apoptose/efeitos dos fármacos , Biomarcadores/análise , Western Blotting/métodos , Caspases/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Difosfonatos/farmacologia , Feminino , Humanos , Proteínas Inibidoras de Apoptose , Células Jurkat , Leucemia de Células T/metabolismo , Leucemia-Linfoma de Células T do Adulto/tratamento farmacológico , Leucemia-Linfoma de Células T do Adulto/metabolismo , Masculino , Camundongos , Camundongos SCID , Proteínas Associadas aos Microtúbulos/análise , Proteínas Associadas aos Microtúbulos/metabolismo , Pessoa de Meia-Idade , Proteínas de Neoplasias/análise , Proteínas de Neoplasias/metabolismo , Transplante de Neoplasias , Transdução de Sinais/efeitos dos fármacos , Survivina , Linfócitos T/virologiaRESUMO
The molecular chaperone Hsp90 is involved in the stabilization and conformational maturation of many signaling proteins that are deregulated in cancers. The geldanamycin derivative 17-AAG is currently tested in clinical trials and known to inhibit the function of Hsp90 and promote the proteasomal degradation of its misfolded client proteins. ATL is a fatal malignancy of T lymphocytes caused by HTLV-I infection and remains incurable. Since Hsp90 is overexpressed in HTLV-I-infected T-cell lines and primary ATL cells, we analyzed the effects of 17-AAG on cell survival, apoptosis and expression of signal transduction proteins. HTLV-I-infected T-cell lines and primary ATL cells were significantly more sensitive to 17-AAG in cell survival assays than normal PBMCs. 17-AAG induced the inhibition of cell cycle and apoptosis. These effects could be mediated by inactivation of NF-kappaB, AP-1 and PI3K/Akt pathways, as well as reduction of expression of proteins involved in the G1-S cell cycle transition and apoptosis. Proteasome inhibition interfered with 17-AAG-mediated signaling proteins depletion. Collectively, our results indicate that 17-AAG suppresses ATL cell survival through, at least in part, destabilization of several client proteins and suggest that 17-AAG is a potentially useful chemotherapeutic agent for ATL.
Assuntos
Apoptose/efeitos dos fármacos , Benzoquinonas/uso terapêutico , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Vírus Linfotrópico T Tipo 1 Humano/efeitos dos fármacos , Lactamas Macrocíclicas/uso terapêutico , Leucemia de Células T/tratamento farmacológico , Leucemia-Linfoma de Células T do Adulto/tratamento farmacológico , Linfócitos T/virologia , Adulto , Ciclo Celular/efeitos dos fármacos , Humanos , Leucemia de Células T/virologia , Leucemia-Linfoma de Células T do Adulto/virologia , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Linfócitos T/efeitos dos fármacos , Fator de Transcrição AP-1/metabolismo , Células Tumorais CultivadasRESUMO
ATL is a fatal malignancy of T lymphocytes caused by HTLV-I infection and remains incurable. Galectins are a family of animal lectins that function both extracellularly (by interacting with cell surface and extracellular matrix glycoproteins and glycolipids) and intracellularly (by interacting with cytoplasmic and nuclear proteins) to modulate signaling pathways. We found that protease-resistant galectin-9 by modification of its linker peptide, hG9NC(null), prevented cell growth of HTLV-I-infected T-cell lines and primary ATL cells. The suppression of cell growth was inhibited by lactose, but not by sucrose, indicating that beta-galactoside binding is essential for hG9NC(null)-induced cell growth suppression. hG9NC(null) induced cell cycle arrest by reducing the expression of cyclin D1, cyclin D2, cyclin B1, Cdk1, Cdk4, Cdk6, Cdc25C and c-Myc, and apoptosis by reducing the expression of XIAP, c-IAP2 and survivin. Most of these genes are regulated by NF-kappaB, which plays a critical role in oncogenesis by HTLV-I. hG9NC(null) suppressed IkappaBalpha phosphorylation, resulting in suppression of NF-kappaB. Most importantly, treatment with hG9NC(null) (6.7 mg/kg injected intraperitoneally every day) reduced tumor formation from an HTLV-I-infected T-cell line when these cells were inoculated subcutaneously into SCID mice. Our results suggest that hG9NC(null) could be a suitable agent for the management of ATL.