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1.
Respirology ; 14(2): 302-4, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19192229

RESUMO

Chronic cough is caused by a wide variety of disease conditions, including asthma, rhino-sinusitis and gastro-oesophageal reflux. We describe the case of a 42-year-old man with hypereosinophilic syndrome presenting with chronic dry cough. The cough did not respond to inhaled corticosteroid or leucotriene receptor antagonists. Hepatosplenomegaly was noted and the patient became anaemic and thrombocytopenic. He was refractory to treatment with hydroxyurea and interferon-alpha. Administration of imatinib resulted in complete resolution of eosinophilia and cough, without the use of anti-asthma drugs. Analysis of RNA from this patient demonstrated expression of the Fip1-like 1/platelet-derived growth factor receptor-alpha (FIP1L1-PDGFRA) fusion gene. The myeloproliferative variant of hypereosinophilic syndrome may cause chronic intractable cough, and a trial of imatinib treatment may be warranted.


Assuntos
Tosse/tratamento farmacológico , Tosse/etiologia , Síndrome Hipereosinofílica/complicações , Síndrome Hipereosinofílica/tratamento farmacológico , Piperazinas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Adulto , Benzamidas , Doença Crônica , Humanos , Síndrome Hipereosinofílica/genética , Mesilato de Imatinib , Masculino , Proteínas de Fusão Oncogênica/genética , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Resultado do Tratamento , Fatores de Poliadenilação e Clivagem de mRNA/genética
2.
Leuk Res ; 32(2): 287-96, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17644177

RESUMO

Adult T-cell leukemia/lymphoma (ATL) is a highly aggressive disease with a poor prognosis in which nuclear factor kappa B (NF-kappaB) is thought to play a role. This study explored the effects of histone deacetylase inhibitors (HDACIs) MS-275, suberoylanilide hydroxamic acid (SAHA), and LBH589 on both human T-cell lymphotropic virus type I (HTLV-1)-infected T cells (MT-1, -2, -4, and HUT102) and freshly isolated ATL cells harvested from patients. HDACIs effectively inhibited the proliferation of these cells. For example, MS-275, SAHA, and LBH589 effectively inhibited the proliferation of MT-1 cells with ED(50s) of 6microM, 2.5microM, and 100nM, respectively, as measured by 3-(4,5-dimethylithiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay on day 2 of culture. In addition, HDACIs induced cell cycle arrest at the G2/M phase and apoptosis of HTLV-1-infected T-cells in conjunction with regulation of apoptosis-related proteins. Electrophoretic mobility shift assay showed that exposure of HTLV-1-infected T-cells to HDACIs for 48h inhibited formation of the NF-kappaB/DNA binding complex. Moreover, we found that HDACIs accumulated NF-kappaB and inhibitory subunit of NF-kappaB in the cytoplasm in conjunction with the down-regulation of NF-kappaB in the nucleus, suggesting that HDACIs blocked nuclear translocation of NF-kappaB. Based on these findings, we believe HDACIs can be useful for treating patients with ATL or other types of cancer in which NF-kappaB plays a role.


Assuntos
Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Leucemia-Linfoma de Células T do Adulto/tratamento farmacológico , NF-kappa B/efeitos dos fármacos , Antineoplásicos/farmacologia , Benzamidas/farmacologia , Western Blotting , Linhagem Celular , Infecções por Deltaretrovirus/tratamento farmacológico , Ensaio de Desvio de Mobilidade Eletroforética , Citometria de Fluxo , Inibidores de Histona Desacetilases , Vírus Linfotrópico T Tipo 1 Humano , Humanos , Ácidos Hidroxâmicos/farmacologia , Imuno-Histoquímica , Indóis , Panobinostat , Piridinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Vorinostat
3.
Int J Oncol ; 31(3): 593-600, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17671686

RESUMO

PC-SPES is an eight-herb mixture that has an activity against prostate cancer. Recently, we purified Saw Palmetto (Serenoa repens) from PC-SPES and found that Saw Palmetto induced growth arrest of prostate cancer LNCaP, DU145, and PC3 cells with ED50s of approximately 2.0, 2.6, and 3.3 microl/ml, respectively, as measured by mitochondrial-dependent conversion of the the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Saw Palmetto induced apoptosis of LNCaP cells in a time- and dose-dependent manner as measured by TUNEL assays. Also, Saw Palmetto increased the expression of p21waf1 and p53 protein in LNCaP cells. In addition, we found that Saw Palmetto down-regulated DHT- or IL-6-induced expression of prostate specific antigen in conjunction with down-regulation of the level of androgen receptor in the nucleus as measured by Western blot analysis. Moreover, Saw Palmetto down-regulated the IL-6-induced level of the phosphorylated form of STAT 3 in LNCaP cells. Furthermore, Saw Palmetto inhibited the growth of LNCaP cells present as tumor xenografts in BALB/c nude mice without adverse effect. These results indicate that Saw Palmetto might be useful for the treatment of individuals with prostate cancer.


Assuntos
Antagonistas de Androgênios/farmacologia , Apoptose , Regulação Neoplásica da Expressão Gênica , Extratos Vegetais/farmacologia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Receptores Androgênicos/metabolismo , Fator de Transcrição STAT3/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Interleucina-6/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Antígeno Prostático Específico/biossíntese , Serenoa , Transdução de Sinais
4.
Clin Cancer Res ; 13(12): 3528-35, 2007 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-17575215

RESUMO

PURPOSE: Bone morphogenetic proteins (BMP), belonging to the transforming growth factor-beta superfamily, are important regulators of cell growth, differentiation, and apoptosis. The biological effects of BMPs on malignant lymphoma, however, remain unknown. Promoter methylation of the BMP-6 gene in lymphomas was investigated. EXPERIMENTAL DESIGN: We investigated BMP-6 promoter methylation and its gene expression in various histologic types of 90 primary lymphomas and 30 lymphoma cell lines. The effect of BMP-6 promoter hypermethylation on clinical outcome was also evaluated. RESULTS: BMP-6 was epigenetically inactivated in subsets of lymphomas. The silencing occurred with high frequency in diffuse large B-cell lymphoma (DLBCL) and Burkitt's lymphoma in association with aberrant BMP-6 promoter methylation. The methylation was observed in 60% (21 of 35) of DLBCL cases and 100% (7 of 7) of DLBCL cell lines, and in 83% (5 of 6) of Burkitt's lymphoma cases and 86% (12 of 14) of Burkitt's lymphoma cell lines. In contrast, other histologic types of primary lymphomas studied had little or no detectable methylation (1 of 49; 2%). The presence of BMP-6 promoter hypermethylation in DLBCL statistically correlated with a decrease in disease-free survival (P = 0.014) and overall survival (P = 0.038). Multivariate analysis showed that the methylation profile was an independent prognostic factor in predicting disease-free survival (P = 0.022) and overall survival (P = 0. 046). CONCLUSION: BMP-6 promoter was hypermethylated more often in aggressive types of lymphomas, and the hypermethylation is likely to be related to the histologic type of lymphomas. BMP-6 promoter methylation may be a potential new biomarker of risk prediction in DLBCL.


Assuntos
Proteínas Morfogenéticas Ósseas/genética , Metilação de DNA , Linfoma/genética , Regiões Promotoras Genéticas/genética , Biomarcadores Tumorais/genética , Western Blotting , Proteína Morfogenética Óssea 6 , Linhagem Celular Tumoral , Feminino , Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Linfoma/mortalidade , Linfoma/patologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Risco
5.
Mol Cancer Ther ; 6(6): 1851-7, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17541033

RESUMO

The Aurora kinases play an important role in chromosome alignment, segregation, and cytokinesis during mitosis. Aberrant expression of these kinases occurs in solid tumors and is associated with aneuploidy and carcinogenesis. We found in this study that Aurora kinase A and B were aberrantly expressed in a variety of types of human leukemia cell lines (n = 15, e.g., PALL-1, PALL-2, HL-60, NB4, MV4-11, etc.), as well as freshly isolated leukemia cells from individuals with acute myelogenous leukemia (n = 44) compared with bone marrow mononuclear cells from healthy volunteers (n = 11), as measured by real-time PCR. ZM447439 is a novel selective Aurora kinase inhibitor. The compound induced growth inhibition, caused accumulation of cells with 4N/8N DNA content, and mediated apoptosis of human leukemia cells as measured by thymidine uptake, cell cycle analysis, and annexin V staining, respectively. Especially profound growth inhibition occurred with the PALL-1 and PALL-2 cells, which possess wild-type p53 gene. In contrast, ZM447439 did not inhibit clonogenic growth of myeloid committed stem cells harvested from healthy normal volunteers. Taken together, inhibition of Aurora kinases may be a promising treatment strategy for individuals with leukemia.


Assuntos
Benzamidas/farmacologia , Inibidores Enzimáticos/farmacologia , Leucemia Mieloide Aguda/enzimologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Quinazolinas/farmacologia , Apoptose/efeitos dos fármacos , Aurora Quinase A , Aurora Quinases , Sequência de Bases , Divisão Celular/efeitos dos fármacos , Primers do DNA , Humanos , Leucemia Mieloide Aguda/patologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas
6.
Intern Med ; 46(10): 675-8, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17527042

RESUMO

We describe a 27-year-old man with hypereosinophilc syndrome (HES) presenting acute abdomen due to acute thrombosis of the mesenteric artery, who had a past history of eosinophilic pneumonia followed by multiple arterial thromboses of the extremities. At the recurrence of eosinophilia, he was treated with high-dose corticosteroids. Immediately after the reduction of peripheral blood eosinophils, he suddenly developed perforation of the intestine due to acute thromboses of mesenteric arteries despite sustained anticoagulation therapy. Molecular analysis demonstrated that the FIP1L1-PDGFRA fusion gene was negative. Histopathology showed thrombi and eosinophilic inflammation of arteries. It is important to recognize that HES could be a cause of acute abdomen.


Assuntos
Abdome Agudo/etiologia , Síndrome Hipereosinofílica/complicações , Artérias Mesentéricas/patologia , Trombose/etiologia , Abdome Agudo/cirurgia , Adulto , Glucocorticoides/uso terapêutico , Humanos , Síndrome Hipereosinofílica/tratamento farmacológico , Masculino , Metilprednisolona/uso terapêutico
7.
Blood ; 110(6): 2034-40, 2007 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-17495131

RESUMO

Aurora kinases play an important role in chromosome alignment, segregation, and cytokinesis during mitosis. We have recently shown that hematopoietic malignant cells including those from acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) aberrantly expressed Aurora A and B kinases, and ZM447439, a potent inhibitor of Aurora kinases, effectively induced growth arrest and apoptosis of a variety of leukemia cells. The present study explored the effect of AZD1152, a highly selective inhibitor of Aurora B kinase, on various types of human leukemia cells. AZD1152 inhibited the proliferation of AML lines (HL-60, NB4, MOLM13), ALL line (PALL-2), biphenotypic leukemia (MV4-11), acute eosinophilic leukemia (EOL-1), and the blast crisis of chronic myeloid leukemia K562 cells with an IC50 ranging from 3 nM to 40 nM, as measured by thymidine uptake on day 2 of culture. These cells had 4N/8N DNA content followed by apoptosis, as measured by cell-cycle analysis and annexin V staining, respectively. Of note, AZD1152 synergistically enhanced the antiproliferative activity of vincristine, a tubulin depolymerizing agent, and daunorubicin, a topoisomerase II inhibitor, against the MOLM13 and PALL-2 cells in vitro. Furthermore, AZD1152 potentiated the action of vincristine and daunorubicin in a MOLM13 murine xenograft model. Taken together, AZD1152 is a promising new agent for treatment of individuals with leukemia. The combined administration of AZD1152 and conventional chemotherapeutic agent to patients with leukemia warrants further investigation.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Leucemia/tratamento farmacológico , Organofosfatos/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Quinazolinas/farmacologia , Moduladores de Tubulina/farmacologia , Animais , Aurora Quinase A , Aurora Quinase B , Aurora Quinases , Estudos de Casos e Controles , Ciclo Celular/efeitos dos fármacos , Ensaio de Unidades Formadoras de Colônias , Daunorrubicina/farmacologia , Sinergismo Farmacológico , Quimioterapia Combinada , Tolerância a Medicamentos , Inibidores Enzimáticos/farmacologia , Feminino , Citometria de Fluxo , Humanos , Immunoblotting , Leucemia/enzimologia , Leucemia/patologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Serina-Treonina Quinases/metabolismo , Timidina/metabolismo , Transplante Heterólogo , Vincristina/farmacologia
8.
Lung Cancer ; 57(3): 399-403, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17397962

RESUMO

Cancer-associated retinopathy (CAR) is a rare paraneoplastic disorder that is frequently found in patients with small cell lung cancer (SCLC); it is caused by autoantibody to the 23-kDa photoreceptor protein, recoverin. We report a 9-year survivor of SCLC after concurrent chemoradiotherapy. His anti-recoverin antibody remains positive. Long-term survival without SCLC recurrence might be related to an autoimmunity mechanism that causes CAR due to the presence of anti-recoverin antibody cross-reacting with retinal cells and tumor cells. The current literature review was conducted to evaluate the impact on overall survival according to anti-recoverin antibody status.


Assuntos
Doenças Autoimunes/mortalidade , Carcinoma de Células Pequenas/mortalidade , Neoplasias Pulmonares/mortalidade , Doenças Retinianas/mortalidade , Idoso , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Carcinoma de Células Pequenas/complicações , Carcinoma de Células Pequenas/patologia , Feminino , Humanos , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Doenças Retinianas/imunologia , Doenças Retinianas/patologia , Análise de Sobrevida
11.
Oncol Rep ; 17(4): 955-61, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17342342

RESUMO

We examined the effects of granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) on the lung cancer cell lines PC-9, LA-1 and A549. In addition, we examined if the effects of the cytokines on the cell lines are mediated by activation of cyclooxygenase (COX)-2. The three cell lines did not constitutively produce either G-CSF or GM-CSF. G-CSF did not influence cell growth in the three cell lines, while GM-CSF increased cell growth in the A549 and LA-1 lines. G-CSF and GM-CSF dose-dependently decreased cell death in the three cell lines. RT-PCR demonstrated GM-CSF receptor expression in the three lung cancer cell lines, whereas the G-CSF receptor exists only in the PC-9 line. We suggest that G-CSF might rescue the tumor cells from cytotoxicity due to serum deprivation through cellular pathways independent of the G-CSF receptor. G-CSF and GM-CSF increased cyclooxygenase-2 (COX-2) expression in PC-9 and LA-1 cells whereas they decreased COX-2 expression in A549 cells. The COX-2 inhibitor NS-398 increased cell death in PC-9 and LA-1 cells, whereas it decreased cell death in A549 cells. PC-9 and LA-1 clones transfected with sense G-CSF- or GM-CSF showed an increase in COX-2 expression, while COX-2 expression was decreased in transfected A549 clones. COX-2 expression was increased in anti-sense G-CSF- and GM-CSF-transfected A549 clones. Thus, although COX-2 activation seems to induce different biological behavior depending on the cell type, we propose that G-CSF and GM-CSF might accelerate tumor progression by directly regulating COX-2 expression, independently of an autocrine mechanism.


Assuntos
Ciclo-Oxigenase 2/fisiologia , Fator Estimulador de Colônias de Granulócitos/metabolismo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Neoplasias Pulmonares/imunologia , Anticorpos/farmacologia , Apoptose , Linhagem Celular Tumoral , Ciclo-Oxigenase 2/efeitos dos fármacos , Ciclo-Oxigenase 2/genética , Inibidores de Ciclo-Oxigenase/farmacologia , Fator Estimulador de Colônias de Granulócitos/antagonistas & inibidores , Fator Estimulador de Colônias de Granulócitos/farmacologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/antagonistas & inibidores , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Humanos , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/patologia , Nitrobenzenos/farmacologia , Receptores de Fator Estimulador de Colônias de Granulócitos/metabolismo , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/metabolismo , Sulfonamidas/farmacologia
12.
Clin Cancer Res ; 13(5): 1399-404, 2007 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-17332281

RESUMO

PURPOSE: Epigenetic events are a critical factor contributing to cancer development. The purpose of this study was to identify tumor suppressor genes silenced by DNA methylation and histone deacetylation in non-small cell lung cancer (NSCLC). EXPERIMENTAL DESIGN: We used microarray analysis to screen for tumor suppressor genes. RESULTS: We identified Per1, a core circadian gene, as a candidate tumor suppressor in lung cancer. Although Per1 levels were high in normal lung, its expression was low in a large panel of NSCLC patient samples and cell lines. Forced expression of Per1 in NSCLC cell lines led to significant growth reduction and loss of clonogenic survival. Recent studies showed that epigenetic regulation, particularly histone H3 acetylation, is essential for circadian function. Using bisulfite sequencing and chromatin immunoprecipitation, we found that DNA hypermethylation and histone H3 acetylation are potential mechanisms for silencing Per1 expression NSCLC. CONCLUSIONS: These results support the hypothesis that disruption of circadian rhythms plays an important role in lung tumorigenesis. Moreover, our findings suggest a novel link between circadian epigenetic regulation and cancer development.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Proteínas de Ciclo Celular/genética , Ritmo Circadiano/fisiologia , Inativação Gênica , Genes Supressores de Tumor/fisiologia , Neoplasias Pulmonares/genética , Humanos , Imunoprecipitação , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Circadianas Period , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
Lung Cancer ; 56(3): 319-26, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17374419

RESUMO

We analysed the biologic properties of a small cell lung carcinoma cell line (designated KK0206) established from a patient with SCLC who had cancer-associated retinopathy (CAR). Morphological and immunohistochemical studies showed that KK0206 cells have features of the classic type of SCLC. KK0206 cells grew in suspension, forming relatively small clumps of cells with a doubling time of 72 h. On light microscopy, the cells were relatively small with little cytoplasm. On immunohistochemistry using anti-bovine recoverin rabbit antibody, the cells were intensely positive for recoverin. In addition, they were positive for NSE, Ki-67, and TP53. They also expressed human recoverin, a photoreceptor protein, whose presence was confirmed by RT-PCR analysis with cDNA sequencing and Western blot analysis. The point mutation of their TP53 gene (exon 156) was detected as well. The present study demonstrates that human recoverin is expressed in SCLC cells cultured from an anti-recoverin antibody-negative patient with CAR. KK0206 might be important for further research on SCLC related retinopathy.


Assuntos
Carcinoma de Células Pequenas/complicações , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/complicações , Síndromes Paraneoplásicas/genética , Recoverina/genética , Doenças Retinianas/genética , Adulto , Biomarcadores Tumorais , Northern Blotting , Carcinoma de Células Pequenas/diagnóstico , Linhagem Celular Tumoral , Progressão da Doença , Eletrorretinografia , Evolução Fatal , Seguimentos , Genes p53/genética , Humanos , Imuno-Histoquímica , Neoplasias Pulmonares/diagnóstico , Masculino , Síndromes Paraneoplásicas/diagnóstico , Síndromes Paraneoplásicas/etiologia , Mutação Puntual , Recoverina/biossíntese , Doenças Retinianas/diagnóstico , Doenças Retinianas/etiologia , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tomografia Computadorizada por Raios X
14.
Nihon Kokyuki Gakkai Zasshi ; 45(1): 65-70, 2007 Jan.
Artigo em Japonês | MEDLINE | ID: mdl-17313030

RESUMO

A 39 year-old Japanese man who had been treated for pleuritis developed a tumor in the left lung and was admitted to our hospital. Although evidence of tuberculous pleurisy was not proved medically, he had been treated successfully with antituberculous drugs for 9 months. Two months after completion of antituberculous therapy, his X-ray showed a tumor shadow close to his left hilum. A computed tomography (CT) scan showed a left lung tumor with a diameter of 3.3cm, atelectasis in an ajacent field, and no effusion. Tumor markers targeted for lung cancer remained within normal range. Bronchofiberscopy demonstrated a polypoid tumor from left upper lobe bronchus. The pathological examination of CT guided percutaneous biopsy (CTGB) specimen revealed undifferentiated malignant tumor. A pulmonary angiogram disclosed almost complete obstruction of left pulmonary artery. He underwent total pneumonectomy of the left lung, and the final pathological diagnosis of pulmonary artery sarcoma was made. He received neither chemotherapy nor radiotherapy. He is well and disease free 3 years after resection. Surgical resection may improve the prognosis of this malignancy.


Assuntos
Neoplasias Pulmonares/cirurgia , Pneumonectomia , Artéria Pulmonar , Sarcoma/cirurgia , Neoplasias Vasculares/cirurgia , Adulto , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Masculino , Derrame Pleural Maligno/etiologia , Prognóstico , Artéria Pulmonar/cirurgia , Radiografia Torácica , Sobreviventes , Tomografia Computadorizada por Raios X , Neoplasias Vasculares/diagnóstico por imagem
18.
Leuk Res ; 31(5): 673-82, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17007924

RESUMO

This study found that phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling was activated in human T-cell lymphotropic virus type I (HTLV-1)-infected leukemia cells. Rapamycin (1-100 nM, 48h), the inhibitor of mTOR and its analog RAD001 (1-100 nM, 48 h)-induced growth inhibition and G0/G1 cell cycle arrest of these cells in association with de-phosphorylation of p70S6K and 4E-BP-1, although IC50 was not achieved. Paradoxically, rapamycin-stimulated phosphorylation of Akt at Ser473. Blockade of Akt signaling by the PI3K inhibitor LY294002 (1-20 microM, 48 h) also resulted in the growth inhibition and G0/G1 cell cycle arrest of HTLV-1-infected cells, with IC50 ranging from 5 to 20muM, and it caused de-phosphorylation of p70S6K and 4E-BP-1. Of note, when rapamycin was combined with LY294002, rapamycin-induced phosphorylation of Akt was blocked, and the ability of rapamycin to induce growth arrest of HTLV-1-infected T-cells and suppress the p-p70S6K and p-4E-BP-1 proteins was potentiated. Moreover, both LY294002 and rapamycin down-regulated the levels of c-Myc and cyclin D1 proteins in these cells, and their combination further decreased levels of these cell cycle-regulating proteins. Taken together, longitudinal inhibition of PI3K/Akt/mTOR signaling represents a promising treatment strategy for individuals with adult T-cell leukemia.


Assuntos
Cromonas/farmacologia , Leucemia-Linfoma de Células T do Adulto/patologia , Morfolinas/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase , Proteínas Quinases , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Sirolimo/farmacologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Ciclo Celular/efeitos dos fármacos , Proteínas de Ciclo Celular , Ciclina D , Ciclinas/metabolismo , Inibidores Enzimáticos/farmacologia , Vírus Linfotrópico T Tipo 1 Humano , Humanos , Imunossupressores/farmacologia , Leucemia-Linfoma de Células T do Adulto/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosfoproteínas/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/antagonistas & inibidores , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais/efeitos dos fármacos , Linfócitos T/metabolismo , Linfócitos T/virologia , Serina-Treonina Quinases TOR , Células Tumorais Cultivadas
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