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1.
Respirology ; 14(2): 302-4, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19192229

RESUMEN

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.


Asunto(s)
Tos/tratamiento farmacológico , Tos/etiología , Síndrome Hipereosinofílico/complicaciones , Síndrome Hipereosinofílico/tratamiento farmacológico , Piperazinas/uso terapéutico , Inhibidores de Proteínas Quinasas/uso terapéutico , Pirimidinas/uso terapéutico , Adulto , Benzamidas , Enfermedad Crónica , Humanos , Síndrome Hipereosinofílico/genética , Mesilato de Imatinib , Masculino , Proteínas de Fusión Oncogénica/genética , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/genética , Resultado del Tratamiento , Factores de Escisión y Poliadenilación de ARNm/genética
2.
Leuk Res ; 32(2): 287-96, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17644177

RESUMEN

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.


Asunto(s)
Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Leucemia-Linfoma de Células T del Adulto/tratamiento farmacológico , FN-kappa B/efectos de los fármacos , Antineoplásicos/farmacología , Benzamidas/farmacología , Western Blotting , Línea Celular , Infecciones por Deltaretrovirus/tratamiento farmacológico , Ensayo de Cambio de Movilidad Electroforética , Citometría de Flujo , Inhibidores de Histona Desacetilasas , Virus Linfotrópico T Tipo 1 Humano , Humanos , Ácidos Hidroxámicos/farmacología , Inmunohistoquímica , Indoles , Panobinostat , Piridinas/farmacología , Transducción de Señal/efectos de los fármacos , Vorinostat
3.
Int J Oncol ; 31(3): 593-600, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17671686

RESUMEN

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.


Asunto(s)
Antagonistas de Andrógenos/farmacología , Apoptosis , Regulación Neoplásica de la Expresión Génica , Extractos Vegetales/farmacología , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Receptores Androgénicos/metabolismo , Factor de Transcripción STAT3/metabolismo , Animales , Línea Celular Tumoral , Proliferación Celular , Humanos , Interleucina-6/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Antígeno Prostático Específico/biosíntesis , Serenoa , Transducción de Señal
4.
Clin Cancer Res ; 13(12): 3528-35, 2007 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-17575215

RESUMEN

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.


Asunto(s)
Proteínas Morfogenéticas Óseas/genética , Metilación de ADN , Linfoma/genética , Regiones Promotoras Genéticas/genética , Biomarcadores de Tumor/genética , Western Blotting , Proteína Morfogenética Ósea 6 , Línea Celular Tumoral , Femenino , Expresión Génica , Humanos , Estimación de Kaplan-Meier , Linfoma/mortalidad , Linfoma/patología , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Riesgo
5.
Mol Cancer Ther ; 6(6): 1851-7, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17541033

RESUMEN

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.


Asunto(s)
Benzamidas/farmacología , Inhibidores Enzimáticos/farmacología , Leucemia Mieloide Aguda/enzimología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Quinazolinas/farmacología , Apoptosis/efectos de los fármacos , Aurora Quinasa A , Aurora Quinasas , Secuencia de Bases , División Celular/efectos de los fármacos , Cartilla de ADN , Humanos , Leucemia Mieloide Aguda/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales Cultivadas
6.
Intern Med ; 46(10): 675-8, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17527042

RESUMEN

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.


Asunto(s)
Abdomen Agudo/etiología , Síndrome Hipereosinofílico/complicaciones , Arterias Mesentéricas/patología , Trombosis/etiología , Abdomen Agudo/cirugía , Adulto , Glucocorticoides/uso terapéutico , Humanos , Síndrome Hipereosinofílico/tratamiento farmacológico , Masculino , Metilprednisolona/uso terapéutico
7.
Blood ; 110(6): 2034-40, 2007 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-17495131

RESUMEN

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.


Asunto(s)
Antibióticos Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Leucemia/tratamiento farmacológico , Organofosfatos/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Quinazolinas/farmacología , Moduladores de Tubulina/farmacología , Animales , Aurora Quinasa A , Aurora Quinasa B , Aurora Quinasas , Estudios de Casos y Controles , Ciclo Celular/efectos de los fármacos , Ensayo de Unidades Formadoras de Colonias , Daunorrubicina/farmacología , Sinergismo Farmacológico , Quimioterapia Combinada , Tolerancia a Medicamentos , Inhibidores Enzimáticos/farmacología , Femenino , Citometría de Flujo , Humanos , Immunoblotting , Leucemia/enzimología , Leucemia/patología , Ratones , Ratones Endogámicos BALB C , Proteínas Serina-Treonina Quinasas/metabolismo , Timidina/metabolismo , Trasplante Heterólogo , Vincristina/farmacología
8.
Lung Cancer ; 57(3): 399-403, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17397962

RESUMEN

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.


Asunto(s)
Enfermedades Autoinmunes/mortalidad , Carcinoma de Células Pequeñas/mortalidad , Neoplasias Pulmonares/mortalidad , Enfermedades de la Retina/mortalidad , Anciano , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/patología , Carcinoma de Células Pequeñas/complicaciones , Carcinoma de Células Pequeñas/patología , Femenino , Humanos , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Enfermedades de la Retina/inmunología , Enfermedades de la Retina/patología , Análisis de Supervivencia
11.
Oncol Rep ; 17(4): 955-61, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17342342

RESUMEN

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.


Asunto(s)
Ciclooxigenasa 2/fisiología , Factor Estimulante de Colonias de Granulocitos/metabolismo , Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Neoplasias Pulmonares/inmunología , Anticuerpos/farmacología , Apoptosis , Línea Celular Tumoral , Ciclooxigenasa 2/efectos de los fármacos , Ciclooxigenasa 2/genética , Inhibidores de la Ciclooxigenasa/farmacología , Factor Estimulante de Colonias de Granulocitos/antagonistas & inhibidores , Factor Estimulante de Colonias de Granulocitos/farmacología , Factor Estimulante de Colonias de Granulocitos y Macrófagos/antagonistas & inhibidores , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Humanos , Neoplasias Pulmonares/enzimología , Neoplasias Pulmonares/patología , Nitrobencenos/farmacología , Receptores de Factor Estimulante de Colonias de Granulocito/metabolismo , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Sulfonamidas/farmacología
12.
Clin Cancer Res ; 13(5): 1399-404, 2007 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-17332281

RESUMEN

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.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/genética , Proteínas de Ciclo Celular/genética , Ritmo Circadiano/fisiología , Silenciador del Gen , Genes Supresores de Tumor/fisiología , Neoplasias Pulmonares/genética , Humanos , Inmunoprecipitación , Análisis de Secuencia por Matrices de Oligonucleótidos , Proteínas Circadianas Period , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
13.
Lung Cancer ; 56(3): 319-26, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17374419

RESUMEN

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.


Asunto(s)
Carcinoma de Células Pequeñas/complicaciones , Regulación Neoplásica de la Expresión Génica , Neoplasias Pulmonares/complicaciones , Síndromes Paraneoplásicos/genética , Recoverina/genética , Enfermedades de la Retina/genética , Adulto , Biomarcadores de Tumor , Northern Blotting , Carcinoma de Células Pequeñas/diagnóstico , Línea Celular Tumoral , Progresión de la Enfermedad , Electrorretinografía , Resultado Fatal , Estudios de Seguimiento , Genes p53/genética , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/diagnóstico , Masculino , Síndromes Paraneoplásicos/diagnóstico , Síndromes Paraneoplásicos/etiología , Mutación Puntual , Recoverina/biosíntesis , Enfermedades de la Retina/diagnóstico , Enfermedades de la Retina/etiología , Estudios Retrospectivos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tomografía Computarizada por Rayos X
14.
Nihon Kokyuki Gakkai Zasshi ; 45(1): 65-70, 2007 Jan.
Artículo en Japonés | MEDLINE | ID: mdl-17313030

RESUMEN

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.


Asunto(s)
Neoplasias Pulmonares/cirugía , Neumonectomía , Arteria Pulmonar , Sarcoma/cirugía , Neoplasias Vasculares/cirugía , Adulto , Humanos , Neoplasias Pulmonares/diagnóstico por imagen , Masculino , Derrame Pleural Maligno/etiología , Pronóstico , Arteria Pulmonar/cirugía , Radiografía Torácica , Sobrevivientes , Tomografía Computarizada por Rayos X , Neoplasias Vasculares/diagnóstico por imagen
18.
Leuk Res ; 31(5): 673-82, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17007924

RESUMEN

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.


Asunto(s)
Cromonas/farmacología , Leucemia-Linfoma de Células T del Adulto/patología , Morfolinas/farmacología , Inhibidores de las Quinasa Fosfoinosítidos-3 , Proteínas Quinasas , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Sirolimus/farmacología , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Ciclo Celular/efectos de los fármacos , Proteínas de Ciclo Celular , Ciclina D , Ciclinas/metabolismo , Inhibidores Enzimáticos/farmacología , Virus Linfotrópico T Tipo 1 Humano , Humanos , Inmunosupresores/farmacología , Leucemia-Linfoma de Células T del Adulto/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfoproteínas/metabolismo , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo , Proteínas Quinasas S6 Ribosómicas 70-kDa/antagonistas & inhibidores , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Transducción de Señal/efectos de los fármacos , Linfocitos T/metabolismo , Linfocitos T/virología , Serina-Treonina Quinasas TOR , Células Tumorales Cultivadas
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