RESUMEN
PURPOSE: We evaluated the safety and efficacy of exisulind for delaying disease progression in men with increasing prostate specific antigen (PSA) after radical prostatectomy. MATERIALS AND METHODS: A total of 96 men with increasing PSA after radical prostatectomy were randomized to receive placebo (49) or 250 mg. exisulind twice daily (47) for 12 months. The primary efficacy parameter was the difference in change from baseline PSA between the placebo and exisulind groups. The PSA doubling time was also evaluated before and during study. A subgroup analysis classified patients based on the risk of developing metastatic disease. RESULTS: Compared with placebo, exisulind significantly suppressed the increase in PSA in all patients (p = 0.017). The results were also statistically significant in men at high risk for metastasis (p = 0.0003) and those who could not be classified according to risk (p = 0.0009). In addition, median PSA doubling time was lengthened in high risk patients on exisulind (2.12 month increase) compared with those on placebo (3.37 month decrease, p = 0.048). Exisulind was well tolerated. CONCLUSIONS: Exisulind inhibited the increase in PSA overall and prolonged PSA doubling time in high risk patients compared with placebo. These results suggest that Exisulind has the potential to extend the time from biochemical recurrence to the need for androgen deprivation therapy. Exisulind was well tolerated in this patient population. Our results support further study of Exisulind in the treatment of patients with prostate cancer.
Asunto(s)
Antineoplásicos/uso terapéutico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Prostatectomía , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/cirugía , Sulindac/uso terapéutico , Anciano , Anciano de 80 o más Años , Terapia Combinada , Método Doble Ciego , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/sangre , Complicaciones Posoperatorias/epidemiología , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/sangre , Sulindac/análogos & derivadosRESUMEN
Nucleotide sequencing and phylogenetic analysis of 10 recognized prototype strains of the porcine enterovirus (PEV) cytopathic effect (CPE) group I reveals a close relationship of the viral genomes to the previously sequenced strain F65, supporting the concept of a reclassification of this virus group into a new picornavirus genus. Also, nucleotide sequences of the polyprotein-encoding genome region or the P1 region of 28 historic strains and recent field isolates were determined. The data suggest that several closely related but antigenically and molecular distinct serotypes constitute one species within the proposed genus Teschovirus. Based on sequence data and serological data, we propose a new serotype with strain Dresden as prototype. This hitherto unrecognized serotype is closely related to porcine teschovirus 1 (PTV-1, former PEV-1), but induces type-specific neutralizing antibodies. Sequencing of field isolates collected from animals presenting with neurological disorders prove that other serotypes than PTV-1 may also cause polioencephalomyelitis of swine.
Asunto(s)
Infecciones por Enterovirus/veterinaria , Enterovirus Porcinos/clasificación , Enterovirus Porcinos/genética , Genoma Viral , Filogenia , Enfermedades de los Porcinos/virología , Regiones no Traducidas 3' , Regiones no Traducidas 5' , Animales , Secuencia de Bases , Infecciones por Enterovirus/virología , Enterovirus Porcinos/inmunología , Evolución Molecular , Técnica del Anticuerpo Fluorescente Indirecta , Datos de Secuencia Molecular , Pruebas de Neutralización , Conformación de Ácido Nucleico , Fenotipo , ARN Ribosómico 18S/genética , ARN Viral/genética , Alineación de Secuencia , Serotipificación , PorcinosRESUMEN
Porcine enteroviruses (PEV) comprising at least 13 serotypes grouped into three species are described as causative agents of neurological disorders, fertility disorders, and dermal lesions of swine. Despite their well-documented acid stability, enteric infection route, and similarity of clinical symptoms, most of the porcine enterovirus (PEV) serotypes are set apart from the genus Enterovirus of the Picornaviridae. Hence, PCR procedures used commonly to detect enteroviruses are not applicable to epizootic relevant PEV serotypes. A nested RT-PCR protocol is described now suited to detect all known porcine enterovirus serotypes using three sets of primer pairs. These primer pairs were designed to amplify either highly conserved sequences of the 5'-nontranslated region (5'-NTR) or the polymerase gene region of the relevant virus species. All 13 acknowledged serotypes of three PEV species and several field isolates of clinical specimens were detectable. The specificity of the PCR procedure is supported by the observation that RT-PCR-positive field isolates coincide with serological PEV classification. PEV PCR is more rapid and less laborious than the time-consuming virus isolation by tissue culture techniques over several passages and serotyping. Because other viruses such as classical swine fever virus, pseudorabies virus, porcine parvovirus, swine vesicular disease virus, and foot-and-mouth disease virus may cause diseases with similar clinical symptoms, PCR detection of all PEVs closes a diagnostic gap and offers the opportunity to use comprehensive PCR procedures for the diagnosis of all relevant viruses causing such symptoms.
Asunto(s)
Infecciones por Enterovirus/veterinaria , Enterovirus Porcinos/aislamiento & purificación , ARN Viral/aislamiento & purificación , Enfermedades de los Porcinos/virología , Regiones no Traducidas 5' , Animales , Secuencia de Bases , Efecto Citopatogénico Viral , Cartilla de ADN , ARN Polimerasas Dirigidas por ADN/genética , Infecciones por Enterovirus/virología , Enterovirus Porcinos/clasificación , Enterovirus Porcinos/genética , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa/métodos , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Alineación de Secuencia , Serotipificación , PorcinosRESUMEN
BACKGROUND: The conviction that postoperative radiotherapy and chemotherapy represent an acceptable standard of care for patients with Dukes' B (stage II) and Dukes' C (stage III) carcinoma of the rectum evolved in the absence of data from clinical trials designed to determine whether the addition of radiotherapy results in improved disease-free survival and overall survival. This study was carried out to address this issue. An additional aim was to determine whether leucovorin (LV)-modulated 5-fluorouracil (5-FU) is superior to the combination of 5-FU, semustine, and vincristine (MOF) in men. PATIENTS AND METHODS: Eligible patients (n = 694) with Dukes' B or C carcinoma of the rectum were enrolled in National Surgical Adjuvant Breast and Bowel Project (NSABP) Protocol R-02 from September 1987 through December 1992 and were followed. They were randomly assigned to receive either postoperative adjuvant chemotherapy alone (n = 348) or chemotherapy with postoperative radiotherapy (n = 346). All female patients (n = 287) received 5-FU plus LV chemotherapy; male patients received either MOF (n = 207) or 5-FU plus LV (n = 200). Primary analyses were carried out by use of a stratified log-rank statistic; P values are two-sided. RESULTS: The average time on study for surviving patients is 93 months as of September 30, 1998. Postoperative radiotherapy resulted in no beneficial effect on disease-free survival (P =.90) or overall survival (P =.89), regardless of which chemotherapy was utilized, although it reduced the cumulative incidence of locoregional relapse from 13% to 8% at 5-year follow-up (P =.02). Male patients who received 5-FU plus LV demonstrated a statistically significant benefit in disease-free survival at 5 years compared with those who received MOF (55% versus 47%; P =.009) but not in 5-year overall survival (65% versus 62%; P =.17). CONCLUSIONS: The addition of postoperative radiation therapy to chemotherapy in Dukes' B and C rectal cancer did not alter the subsequent incidence of distant disease, although there was a reduction in locoregional relapse when compared with chemotherapy alone.
Asunto(s)
Antimetabolitos Antineoplásicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Fluorouracilo/uso terapéutico , Neoplasias del Recto/tratamiento farmacológico , Neoplasias del Recto/radioterapia , Antimetabolitos Antineoplásicos/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Quimioterapia Adyuvante , Terapia Combinada , Supervivencia sin Enfermedad , Esquema de Medicación , Femenino , Fluorouracilo/administración & dosificación , Fluorouracilo/efectos adversos , Humanos , Leucovorina/uso terapéutico , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias del Recto/patología , Neoplasias del Recto/cirugía , Semustina/administración & dosificación , Factores Sexuales , Análisis de Supervivencia , Factores de Tiempo , Vincristina/administración & dosificaciónRESUMEN
BACKGROUND: National Surgical Adjuvant Breast and Bowel Project (NSABP) protocol C-03 showed a benefit from leucovorin (LV)-modulated 5-fluorouracil (5-FU) adjuvant therapy (5-FU + LV) in patients with Dukes' stage B or C carcinoma of the colon. Preclinical and clinical phase I/II data suggested that interferon alfa-2a (IFN) enhanced the efficacy of 5-FU therapy. Accordingly, in NSABP protocol C-05, the addition of recombinant IFN to 5-FU + LV adjuvant therapy was evaluated. METHODS: Data are presented for 2176 patients with Dukes' stage B or C cancer entered onto protocol C-05 during the period from October 1991 through February 1994. Individuals with an Eastern Cooperative Oncology Group performance status of 0-2 (ranges from fully active to ambulatory and capable of self-care but unable to work), a life expectancy of at least 10 years, and curative resection were stratified by sex, disease stage, and number of involved lymph nodes and were randomly assigned to receive either 5-FU + LV or 5-FU + LV + IFN; the mean time on the study as of June 30, 1997, was 54 months. All statistical tests were two-sided. RESULTS: There was no statistically significant difference in either disease-free survival (5-FU + LV, 69%; 5-FU + LV + IFN, 70%) or overall survival (5-FU + LV, 80%; 5-FU + LV + IFN, 81%) at 4 years of follow-up. Toxic effects of grade 3 or higher were observed in 61.8% of subjects in the group treated with 5-FU + LV and in 72.1% of subjects in the group treated with 5-FU + LV + IFN; fewer patients in the latter group completed protocol-mandated 5-FU + LV therapy than in the former group (77.1% versus 88.5%). CONCLUSION: The addition of IFN to 5-FU + LV adjuvant therapy confers no statistically significant benefit, but it does increase toxicity.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias del Colon/tratamiento farmacológico , Antimetabolitos Antineoplásicos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Quimioterapia Adyuvante , Neoplasias del Colon/patología , Supervivencia sin Enfermedad , Esquema de Medicación , Femenino , Fluorouracilo/administración & dosificación , Humanos , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Leucovorina/administración & dosificación , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Proteínas Recombinantes , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
Numerous studies have shown spontaneous IL-10 gene expression and synthesis in a variety of peripheral blood or bone marrow-derived leukemic cells. These include B-cells derived from various lymphoproliferative disorders. Since little is known regarding IL-10 expression in leukemic T-cells, we examined clinical specimens of patients with adult T-cell leukemia (ATL) for IL-10 expression. Sera from ATL patients show increased levels of IL-10 when compared with sera from healthy donors. IL-10 is constitutively produced by ATL cells and also by human T-cell leukemia virus type I (HTLV-I)-infected cell lines. It is thought that HTLV-I infection induces gene expression for IL-10. In this review, a transcriptional regulation of IL-10 gene expression by HTLV-I Tax and the possible role of the NF-kappaB pathway are described.
Asunto(s)
Productos del Gen tax/fisiología , Interleucina-10/metabolismo , Leucemia de Células T/metabolismo , Proteínas de Neoplasias/metabolismo , Humanos , Interleucina-10/genética , FN-kappa B/antagonistas & inhibidores , FN-kappa B/fisiología , Proteínas de Neoplasias/genética , Oligonucleótidos Antisentido/farmacología , Factor de Transcripción ReIA , Células Tumorales Cultivadas/efectos de los fármacos , Células Tumorales Cultivadas/metabolismoRESUMEN
Irinotecan is a DNA topoisomerase I inhibitor that has a wide spectrum of activity against human tumors in both preclinical and clinical studies. To evaluate the efficacy of irinotecan in hormone-refractory prostate cancer, we conducted a phase II study in 15 men with metastatic, PSA-progressive disease after primary androgen deprivation. Irinotecan was administered at a dose of 125 mg/m2 weekly for four weeks followed by a two-week rest period; cycles were repeated every six weeks. Response was assessed by evaluation of serial changes in the serum PSA. None of fifteen patients had a decline in PSA of greater than 50%; eight patients had stable disease as a best response. None of three patients with measurable disease had a partial or complete response. Toxicity was primarily hematologic and gastrointestinal, with 40% of patients requiring dose modification due to granulocytopenia and 20% requiring intravenous fluid supplementation after development of diarrhea. There were no treatment-related deaths. We conclude that irinotecan in the dose and schedule used in this trial does not have significant activity against hormone-refractory prostate cancer.
Asunto(s)
Antineoplásicos Fitogénicos/uso terapéutico , Camptotecina/análogos & derivados , Neoplasias de la Próstata/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Antineoplásicos Fitogénicos/efectos adversos , Camptotecina/efectos adversos , Camptotecina/uso terapéutico , Humanos , Irinotecán , Masculino , Persona de Mediana Edad , Antígeno Prostático Específico/sangreRESUMEN
Interleukin-10 (IL-10) is a pleiotropic cytokine which has potent inhibitory effects on macrophages and T cells, and contributes to the regulation of proliferation and differentiation of B cells. Resting HuT 78, a T-cell line derived from a Sezary lymphoma, produced significant amounts of IL-10 compared with another T-cell line, Jurkat. To elucidate the mechanisms by which the IL-10 is expressed, we have analyzed their activity in human T-cell lines. We report here evidence that members of the family of transcription factors nuclear factor-kappa B (NF-kappa B)/Rel can specifically recognize 3 identical sequences located in the 5'-regulatory region of IL-10 gene in resting HuT 78 cells, whereas Jurkat cells expressed high levels of NF-kappa B consisting of p65 and p50 only upon activation with tumor necrosis factor-alpha (TNF-alpha). In HuT 78 cells, p50 was the major component in the NF-kappa B complexes. Exogenous TNF-alpha and the monoclonal antibody to TNF-alpha did not affect IL-10 production and constitutive NF-kappa B binding levels in HuT 78 cells. This study is the first demonstration of a role for NF-kappa B in the IL-10 gene expression, and suggests that its expression does not require TNF-alpha. These novel findings may account for the specific IL-10 gene expression in T cells.
Asunto(s)
Regulación Neoplásica de la Expresión Génica , Interleucina-10/genética , Linfoma de Células T/genética , FN-kappa B/metabolismo , Secuencias Reguladoras de Ácidos Nucleicos , Anticuerpos Monoclonales/farmacología , Secuencia de Bases , ADN/metabolismo , Ensayo de Inmunoadsorción Enzimática , Humanos , Interleucina-10/metabolismo , Células Jurkat , Linfoma de Células T/metabolismo , FN-kappa B/genética , ARN Mensajero/análisis , Síndrome de Sézary/metabolismo , Células Tumorales Cultivadas , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
The expression of interleukin-1 alpha (IL-1 alpha) appears to be tightly regulated, as the levels of constitutive expression in normal cells is extremely low. In contrast to normal hematopoietic cells, human T-cell leukemia virus type I (HTLV-I)-infected T-cell lines constitutively produce high levels of IL-1 alpha mRNA and secret this cytokine into the culture medium. IL-1-alpha mRNA is also expressed in fresh leukemic cells of adult T-cell leukemia/lymphoma (ATLL) patients. HTLV-I-induced IL-1 alpha might explain some symptoms observed in ATLL. In this regard, molecular dissection of the IL-1 alpha gene transcriptional regulation is of primary importance. In this review, the transcriptional regulation of IL-1 alpha gene expression and the possible role of the NF-kappaB pathway are discussed in the light of our current understanding of IL-1 alpha gene regulation by HTLV-I and HTLV-II Tax proteins, which are viral transcriptional transactivators.
Asunto(s)
Productos del Gen tax/fisiología , Virus Linfotrópico T Tipo 1 Humano/genética , Interleucina-1/genética , Regiones Promotoras Genéticas/fisiología , Activación Transcripcional/fisiología , Animales , Humanos , Interleucina-1/biosíntesisRESUMEN
Multiple myeloma cell lines express functional receptors for insulin-like growth factors (IGFs) and several cell types that make up the bone marrow microenvironment produce these cytokines. This suggests that IGFs may play a role in survival and/or expansion of the malignant clone within the marrow in patients with multiple myeloma. We tested the effects of these growth factors on myeloma cells challenged with dexamethasone. Dye exclusion and MTT assays demonstrated that both IGF-I and IGF-II protected the 8226 and dox-40 myeloma cell lines and three primary myeloma cultures from dexamethasone-induced cytotoxicity in a dose-dependent fashion. Morphologic studies of target cells and their nuclei as well as DNA electrophoresis confirmed the IGFs afforded protection against dexamethasone-induced apoptosis. Insulin also protected but was less impressive and required much higher concentrations. IGFs also protected against cycloheximide-induced apoptosis but were ineffective against serum starvation, topoisomerase II inhibitors, or anti-fas antibodies. IGF-induced protection against dexamethasone was not associated with any alteration in quantitative or qualitative expression of BCL-2, BAX or BCL-X proteins. These data indicate that insulin-like growth factors may play a role in maintenance of the malignant clone in patients with myeloma by protecting tumour cells from apoptotic death.
Asunto(s)
Dexametasona/efectos adversos , Factor II del Crecimiento Similar a la Insulina/farmacología , Factor I del Crecimiento Similar a la Insulina/farmacología , Mieloma Múltiple/patología , Animales , Apoptosis/efectos de los fármacos , División Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Insulina/farmacología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Células Tumorales CultivadasRESUMEN
Human T-cell leukemia virus type-I (HTLV-I), the etiologic agent of adult T-cell leukemia (ATL) transforms human T cells both in vivo and in vitro. However, the long latency period between infection and development of ATL, as well as the small fraction of the infected population that actually develops this disease, suggest that factors in addition to the virus are involved in its pathogenesis. Mutation of tumor suppressor gene p53 has been found in both HTLV-I-transformed T-cell lines and ATL cases at relatively low frequency. However, increasing evidence supports p53 functional impairment in HTLV-I-transformed T cells. Tax, the major transactivator of HTLV-I, is critical for the initial events involved in transformation. We have considered the possibility that p53 may regulate transcription of viral and cellular genes important for viral replication and transformation. Inactivation of p53 function might then permit constitutive expression of these viral and cellular genes. We have investigated the effects of wild-type and mutant p53 on Tax-mediated activation of the HTLV-I long terminal repeat (LTR) and the promoters of several cellular genes including the interleukin (IL)-1alpha, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF ), and IL-2 receptor alpha chain gene. Jurkat, HuT78, and U937 cells were cotransfected with plasmids containing a chloramphenicol acetyltransferase (CAT ) reporter gene under viral or cellular promoter control and the Tax expression vector, in addition to vectors for a wild-type or mutant p53. Wild-type p53 is a potent repressor of viral and cellular activation by Tax. Mutations within p53 severely inhibit this downregulation. We also show that wild-type p53 suppresses transcription from the HTLV-I LTR in Jurkat-Tax, a T-cell line stably expressing Tax, and MT-2, a HTLV-I-transformed T-cell line. Wild-type, but not mutant, p53 interfered with the binding of TATA-binding protein (TBP) to the TATA motif of the HTLV-I LTR. These results suggest that p53 inactivation may lead to upregulation of viral and cellular genes and may also be important for establishment of productive viral infection and development of ATL.
Asunto(s)
Virus Linfotrópico T Tipo 1 Humano/genética , Regiones Promotoras Genéticas , Secuencias Repetitivas de Ácidos Nucleicos , Proteínas Represoras/fisiología , Proteína p53 Supresora de Tumor/fisiología , Regulación de la Expresión Génica , Productos del Gen tax/fisiología , Humanos , TATA Box , Activación Transcripcional , Células Tumorales CultivadasRESUMEN
We studied the serum levels of interleukin-10 (IL-10), in patients with adult T-cell leukemia (ATL) caused by human T-cell leukemia virus type I (HTLV-I) infection. Elevated IL-10 levels were observed in 33 of 45 patients with ATL. Fresh leukemic cells from ATL patients as well as HTLV-I-infected T-cell lines MT-2, SLB-1, and C10/MJ expressed IL-10 mRNA by reverse transcription-polymerase chain reaction analysis, whereas IL-10 mRNA was not detected in normal peripheral mononuclear cells and an uninfected T-cell line Jurkat. IL-10 protein was also detected in the culture medium of leukemic cells from ATL patients as well as these HTLV-I-infected cell lines, and in the extracellular fluids of ATL patients. Interestingly, MT-4 cells, which did not express Tax although transformed by HTLV-I, did not express IL-10 at either the mRNA or protein level. To elucidate the role of the HTLV-I encoded transactivator Tax in IL-10 gene expression, Jurkat cells were transfected with a Tax expression plasmid. In transiently transfected Jurkat cells, endogenous IL-10 mRNA expression was induced by Tax. Stably transfected Jurkat cell lines expressed IL-10 mRNA and secreted IL-10 protein into the culture medium. The nuclear factor (NF)-kappa B pathway is a target for Tax transactivation. We treated MT-2 cells with phosphorothioate antisense oligonucleotides to the p65 subunit of NF-kappa B. A reduction in the expression of p65 was accompanied by a reduction in IL-10 gene expression and IL-10 production. We showed that the IL-10 kappa B-like sites ( kappa B1,-2,034 to -2,025; kappa B2, -1,961 to -1,952; kappa B3, -452 to -443) specifically formed a complex with NF-kappa B-containing nuclear extract from MT-2 cells and that NF-kappa B bound with the highest affinity to the kappa B2 element (kappa B2 > kappa B3 > kappa B1). These data suggest a general role for NF-kappa B activation in the induction of IL-10 gene transcription. Activation of IL-10 in HTLV-I-infected cells may contribute to the pathology associated with HTLV-I infection.
Asunto(s)
Regulación Leucémica de la Expresión Génica , Interleucina-10/biosíntesis , Leucemia-Linfoma de Células T del Adulto/genética , Proteínas de Neoplasias/biosíntesis , Adulto , Secuencia de Bases , Líquidos Corporales/química , Productos del Gen tax/metabolismo , Humanos , Interleucina-10/sangre , Interleucina-10/genética , Interleucina-10/metabolismo , Leucemia-Linfoma de Células T del Adulto/sangre , Sustancias Macromoleculares , Datos de Secuencia Molecular , FN-kappa B/metabolismo , Proteínas de Neoplasias/sangre , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Reacción en Cadena de la Polimerasa , ARN Mensajero/biosíntesis , ARN Neoplásico/biosíntesis , Secuencias Reguladoras de Ácidos Nucleicos , Activación Transcripcional , Células Tumorales CultivadasRESUMEN
Human T-cell leukemia virus type I (HTLV-I)-infected T-cell lines constitutively produce high levels of interleukin-1alpha (IL-1alpha). To analyze the mechanisms that lead to the expression of IL-1alpha in HTLV-I-infected cell lines, we studied regulatory regions of the human IL-1alpha promoter involved in activation of the IL-1alpha gene. IL-1alpha promoter constructs drive transcription of the chloramphenicol acetyltransferase (CAT) reporter gene in HTLV-I-positive MT-2 cells, which constitutively produce IL-1alpha. In a cotransfection assay, the Tax protein of both HTLV-I and HTLV-II specifically activated transcription from the IL-1alpha promoter in an uninfected Jurkat cell line. A mutant Tax protein deficient in transactivation of genes by the nuclear factor (NF)-kappaB pathway was unable to induce transcriptional activity of IL-1alpha promoter-CAT constructs, but was rescued by exogenous provision of p65/p50 NF-kappaB. We found that two IL-1alpha kappaB-like sites (positions -1,065 to -1,056 and +646 to +655) specifically formed a complex with NF-kappaB-containing nuclear extract from MT-2 cells and that NF-kappaB bound with higher affinity to the 3' NF-kappaB binding site than to the 5' NF-kappaB site. Moreover, deletion of either 5' or 3' NF-kappaB sites reduced IL-1alpha promoter activity in MT-2 cells and transactivation of the IL-1alpha promoter by exogenous NF-kappaB and Tax in Jurkat cells. These data suggest a general role for Tax induction of IL-1alpha gene transcription by the NF-kappaB pathway. Expression of IL-1alpha by HTLV-I productively infected cells may be important in the hypercalcemia, osteolytic bone lesions, neutrophilia, elevation of C-reactive protein, and fever frequently seen in patients with HTLV-I-induced adult T-cell leukemia/lymphoma.
Asunto(s)
Regulación Viral de la Expresión Génica , Productos del Gen tax/fisiología , Virus Linfotrópico T Tipo 1 Humano/genética , Virus Linfotrópico T Tipo 2 Humano/genética , Interleucina-1/genética , Leucemia-Linfoma de Células T del Adulto/metabolismo , Proteínas de Neoplasias/genética , Células Madre Neoplásicas/metabolismo , Linfocitos T/metabolismo , Activación Transcripcional , Adulto , Secuencia de Bases , Resorción Ósea/etiología , Fiebre/etiología , Regulación Leucémica de la Expresión Génica , Genes Reporteros , Genes pX , Humanos , Hipercalcemia/etiología , Interleucina-1/biosíntesis , Leucemia-Linfoma de Células T del Adulto/complicaciones , Leucemia-Linfoma de Células T del Adulto/genética , Leucemia-Linfoma de Células T del Adulto/patología , Leucemia-Linfoma de Células T del Adulto/virología , Datos de Secuencia Molecular , FN-kappa B/metabolismo , Proteínas de Neoplasias/biosíntesis , Regiones Promotoras Genéticas , Transfección , Células Tumorales CultivadasRESUMEN
Human T-cell leukemia virus type I (HTLV-I) is the etiological agent for adult T-cell leukemia and tropical spastic paraparesis/HTLV-I-associated myelopathy. Recently, the transcription factor AP-2 has been demonstrated to be capable of activating gene expression from HTLV-I long terminal repeat. To determine whether changes occur in the levels of AP-2-binding activity in HTLV-I-infected cell lines, we compared the levels of AP-2 binding of nuclear extracts obtained from HTLV-I-infected T-cell lines with those of nuclear extracts obtained from uninfected T-cell lines. High levels of AP-2-binding activity were observed in HTLV-I-infected cell lines (MT-2, HUT-102, and SLB-1) using the mobility shift assay. In contrast, in the uninfected cell lines (Jurkat, HUT-78, and MLA 144), AP-2-binding activity was obviously low compared with that in the HTLV-I-infected cell lines. HTLV-I transactivator protein tax activates expression of both viral and cellular genes. We have demonstrated further that introduction of the tax gene into Jurkat cells stimulated AP-2-binding activity. These results indicate that HTLV-I-infected T cells exhibit constitutive AP-2-binding activity, and that tax may increase the DNA binding activity of AP-2.
Asunto(s)
Proteínas de Unión al ADN/metabolismo , Genes pX , Virus Linfotrópico T Tipo 1 Humano/genética , Factores de Transcripción/metabolismo , Adulto , Secuencia de Bases , Sitios de Unión , Línea Celular , Núcleo Celular/metabolismo , Virus Linfotrópico T Tipo 1 Humano/metabolismo , Humanos , Leucemia-Linfoma de Células T del Adulto/virología , Datos de Secuencia Molecular , Sondas de Oligonucleótidos , Paraparesia Espástica Tropical/virología , Unión Proteica , Factor de Transcripción AP-2 , Células Tumorales CultivadasRESUMEN
Insulin-like growth factor 1 (IGF-I) is a major feedback regulator of pituitary GH secretion, with defined actions occurring at both the hypothalamus and pituitary. The IGF-I gene is expressed in the anterior pituitary in a GH-dependent manner thus providing for both endocrine-as well as autocrine-mediated GH regulation. In turn, IGF-I selectively and specifically inhibits GH gene transcription and secretion, its attenuating effects on nascent GH mRNA synthesis being demonstrable within 1 h. Binding of IGF-I to its pituitary cell surface receptor is followed by rapid activation of the intrinsic tyrosine kinase activity of the receptor beta-subunit and phosphorylation of insulin receptor substrate 1 (IRS-1). Structure-function studies of the human IGF-I receptor were performed in stable, GH-secreting transfectants expressing either the cDNA encoding the wild-type (WT) human IGF receptor and exhibiting enhanced IGF-I responsiveness, or cDNAs encoding IGF-I receptor mutants and a truncated, kinase-deficient receptor (952STOP). 950Tyr situated on the submembrane receptor domain was found to be critical for transducing the IGF-I signal to the GH gene. IGF-I failed to suppress GH secretion by signalling endogenous rat IGF-I receptors when hybrid receptors were formed with kinase-deficient human receptors and rat hemi-receptors. This dominant negative effect on hormone secretion was also evidenced when mitogenic IGF-I signals were blocked in vitro and in vivo by these hybrid receptors. Using similar doses of IGF-I, the IGF-I receptor cell transfectants also demonstrated ligand-dependent activation of ERKs in pituitary cells. In conclusion, the pituitary IGF-I receptor mediates the negative feedback regulation of GH. Thus, IGF-I receptor mass may determine GH responses to malnutrition, pregnancy, and refeeding. IGF-I receptor mutations may also prove useful to abrogate the growth of IGF-I-dependent tumors. These structure-function studies of the human IGF-I receptor provide mechanistic insights into both metabolic control of the GH axis, as well as target tissue proliferative characteristics.
Asunto(s)
Hormona del Crecimiento/metabolismo , Hipófisis/metabolismo , Receptor IGF Tipo 1/fisiología , Transducción de Señal , Animales , Femenino , Expresión Génica , Hormona del Crecimiento/genética , Humanos , Factor I del Crecimiento Similar a la Insulina/farmacología , Mutación , Embarazo , Receptor IGF Tipo 1/genética , TransfecciónAsunto(s)
Regulación Viral de la Expresión Génica , Productos del Gen tax/metabolismo , Virus Linfotrópico T Tipo 1 Humano/genética , Biosíntesis de Proteínas , Activación Transcripcional , Línea Celular , Citomegalovirus , Cartilla de ADN , Genes pX , Vectores Genéticos , Virus Linfotrópico T Tipo 1 Humano/metabolismo , Humanos , Datos de Secuencia Molecular , Proteína Relacionada con la Hormona Paratiroidea , Reacción en Cadena de la Polimerasa , Proteínas/genética , Linfocitos T , Células Tumorales CultivadasRESUMEN
Interleukin 8 (IL-8) mRNA was detected in peripheral leukemic cells obtained from adult T-cell leukemia patients, as well as in cultured human T-cell leukemia virus type I (HTLV-I)-infected T-cell lines (HUT-102, MT-1, SALT-3, and SKT-1B). With the use of ELISA, IL-8 protein was also detected in the culture medium of these cells and in the extracellular fluids of patients. Furthermore, we demonstrated that the HTLV-I-derived transactivator protein, tax, could stimulate endogenous IL-8 gene expression in an uninfected T-cell line (Jurkat) and in a rheumatoid synovial cell line (E-11). Induction of IL-8 by tax at protein level was also demonstrated in transfected cells. We found that the IL-8 NF-kappa B-binding site specifically formed a complex with NF-kappa B-containing nuclear extracts from HTLV-I-infected T-cell lines and freshly isolated leukemic cells from adult T-cell leukemia patients. Finally, transfection of HTLV-I tax into Jurkat cells resulted in induction of specific binding of nuclear extracts to the NF-kappa B sequence. These results suggest that the HTLV-I tax gene may transactivate the IL-8 gene through the kappa B site in HTLV-I-infected cells and that constitutive expression of the IL-8 gene may play a role in HTLV-I-associated pathogenesis.
Asunto(s)
Genes pX , Virus Linfotrópico T Tipo 1 Humano/genética , Interleucina-8/biosíntesis , Leucemia de Células T/metabolismo , Enfermedad Aguda , Secuencia de Bases , Cartilla de ADN/química , Regulación Neoplásica de la Expresión Génica , Humanos , Técnicas In Vitro , Interleucina-8/genética , Datos de Secuencia Molecular , FN-kappa B/metabolismo , Proteínas Nucleares/metabolismo , ARN Mensajero/genética , ARN Neoplásico/genética , Células Tumorales CultivadasAsunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Mama/cirugía , Carcinoma Ductal de Mama/cirugía , Diagnóstico por Imagen/economía , Mastectomía Segmentaria , Adulto , Neoplasias de la Mama/prevención & control , Carcinoma Ductal de Mama/prevención & control , Quimioterapia Adyuvante , Análisis Costo-Beneficio , Ciclofosfamida/administración & dosificación , Femenino , Fluorouracilo/administración & dosificación , Estudios de Seguimiento , Humanos , Escisión del Ganglio Linfático , Metotrexato/administración & dosificación , Recurrencia Local de Neoplasia/prevención & control , Resultado del TratamientoRESUMEN
Mice bearing retinoblastoma susceptibility gene (RB) germ-line mutations almost invariably develop pituitary neoplasms. We therefore tested 17 patients with pituitary tumors for loss of heterozygosity (LOH) using an RB sequence polymorphism and 5 polymorphic microsatellite markers surrounding the RB gene on the long arm of chromosome 13. In all of the 13 malignant or highly invasive pituitary tumor cases, and in 4 of their respective metastases, a RB allele was lost. In contrast, no LOH at the RB locus was detected in 4 benign pituitary adenoma cases. Three invasive tumors also lost a portion of 13q, which included D13s137, D13s133, and D13s118 telomeric and centromeric to RB, respectively. Immunohistochemical analysis, however, revealed the presence of RB protein in tumors with LOH and the RB locus. Therefore, although inactivation of RB may play a role in the development of invasive pituitary adenomas and carcinomas in mice, another tumor suppressor gene on 13q is likely involved in human pituitary tumor progression. LOH of 13q markers may also be of predictive value in determining the biological behavior of pituitary macroadenomas and their progression to invasiveness and frank malignancy.
Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 13 , Genes de Retinoblastoma , Genes Supresores de Tumor , Neoplasias Hipofisarias/genética , Alelos , Secuencia de Bases , Mapeo Cromosómico , Cartilla de ADN , ADN Satélite/genética , Exones , Marcadores Genéticos , Humanos , Inmunohistoquímica , Datos de Secuencia Molecular , Neoplasias Hipofisarias/patología , Reacción en Cadena de la Polimerasa , Polimorfismo Genético , Proteína de Retinoblastoma/análisisRESUMEN
A number of morphologic and physiologic changes accompany pregnancy such as an increase in lactotrophs and prolactin production, and a decrease in gonadotropins and GH. The hormonal milieu can affect patients with prolactinomas, especially macroadenomas, to cause an increase in size in a minority of patients. Complications are treated with bromocryptine. Enlargement of GH-secreting tumors with acromegaly may respond to bromocryptine and possibly to octreotide. Pituitary tumors causing Cushing's syndrome may need removal if major complications develop. Hypopituitarism during pregnancy may be the result of lymphocytic hypophysitis or antepartum pituitary necrosis, and in the postpartum period may be because of postpartum hemorrhage and pituitary necrosis. These abnormalities need prompt recognition and hormonal replacement therapy with neurosurgical decompression to avoid serious morbidity and mortality. Posterior pituitary problems in pregnancy usually manifest by diabetes insipidus, with a pregnancy-specific variety resulting from excessive degradation of AVP by placental vasopressinase. The condition is treated with an analogue dDAVP, which is resistant to vasopressinase.