RESUMEN
Vestibular schwannoma may present as a sporadic or genetically-based multi-localized benign neoplasm of the internal auditory canal and/or cerebello-pontine angle region. Multiple localization is generally regarded as genetic in origin and often affects the stato-acoustic bundle on both sides. A case of double vestibular schwannoma localized on the same stato-acoustic bundle is presented. After removal, slight histological differences were found between the two separate masses. From these findings, the possibility of a unilateral multiple localization of a vestibular schwannoma is considered plausible within the range of clinical presentation, with negative genetic features. Whether these individual masses might have an autonomous origin or a different growth pattern remains to be fully elucidated.
Asunto(s)
Neuroma Acústico/patología , Humanos , Masculino , Persona de Mediana EdadRESUMEN
CONCLUSION: Distribution of the receptor for epidermal growth factor (EGF-R) and of the receptor for the keratinocyte growth factor (KGF-R) in cholesteatoma was found to differ in analogy with other epithelial tissues and accordingly to epidermal differentiation and intensity of paracrine stimulation. Moreover, both EGF-R and KGF-R expression was increased, suggesting a fair correlation with aggressiveness and recurrence rate of this pathology. OBJECTIVES: To obtain information on the biological behaviour of cholesteatoma by assessing the expression and localization of EGF-R and KGF-R and correlating their tissue distribution with that of cytokeratins as a marker of differentiation. MATERIALS AND METHODS: Cholesteatoma tissue was taken during tympanoplasty surgery and processed for indirect immunofluorescence. Murine monoclonal antibodies were tested for the different growth factor receptors and pancytokeratins analysed. Fluorescence intensity signal was measured on randomly captured digital images, using FISH 2000/HI software, with a pseudocolours generation module. RESULTS: EGF-R was mostly expressed at the level of keratinocytes of the basal layer, while KGF-R signal was mainly distributed on the spinous and granular suprabasal layers that were also highly positive for cytokeratins. Significant correlation between the immunofluorescence signals was found for KGF-R and cytokeratins only, demonstrating that KGF-R expression is increased in more differentiated areas of the cholesteatoma tissue, while EGF-R is associated with proliferative and migratory portions of the lesion.
Asunto(s)
Colesteatoma del Oído Medio/metabolismo , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/biosíntesis , Anticuerpos Monoclonales , Biomarcadores/metabolismo , Colesteatoma del Oído Medio/patología , Receptores ErbB/biosíntesis , Receptores ErbB/inmunología , Técnica del Anticuerpo Fluorescente Indirecta , Humanos , Queratinocitos/metabolismo , Microscopía Fluorescente , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/inmunologíaRESUMEN
Human HaCaT cells, exposed for 24 h to a 1 mT (rms) 50 Hz sinusoidal magnetic field in a temperature-regulated solenoid, suffer detectable changes in their biochemical properties and shapes. By using infrared wavelength-selective scanning near-field optical microscopy, we observed changes in the distribution of the inner chemical functional groups and in the cell morphology with a resolution of 80-100 nm.
Asunto(s)
Campos Electromagnéticos , Queratinocitos , Piel/citología , Línea Celular , Humanos , Rayos Infrarrojos , Queratinocitos/metabolismo , Queratinocitos/efectos de la radiación , Queratinocitos/ultraestructura , Microscopía de Sonda de BarridoRESUMEN
In this study, we show the effect of a 1-mT magnetic field AC at 50 Hz on Xenopus laevis tadpole populations. In the course of a 65-day exposure to the field, tadpole survival showed a small, but significant, decrease (p < 0.0004), together with a striking parallel 6-day shift in tadpole maturation frequency and a significant impairment of their metamorphosis. Particularly, metamorphosis was successful for 85% of individuals in the unirradiated tadpole population and for 45% of individuals in the irradiated tadpole population, respectively.
Asunto(s)
Campos Electromagnéticos/efectos adversos , Larva/efectos de la radiación , Metamorfosis Biológica/efectos de la radiación , Xenopus laevis/fisiología , Animales , Cruzamiento/métodos , Embrión no Mamífero/fisiología , Embrión no Mamífero/efectos de la radiación , Femenino , Masculino , Metamorfosis Biológica/fisiología , Dosis de Radiación , Radiación no Ionizante/efectos adversos , Tasa de SupervivenciaRESUMEN
In this study we have employed atomic force microscopy (AFM) and scanning near-field optical microscopy (SNOM) techniques to study the effect of the interaction between human keratinocytes (HaCaT) and electromagnetic fields at low frequency. HaCaT cells were exposed to a sinusoidal magnetic field at a density of 50 Hz, 1 mT. AFM analysis revealed modification in shape and morphology in exposed cells with an increase in the areas of adhesion between cells. This latter finding was confirmed by SNOM indirect immunofluorescence analysis performed with a fluorescent antibody against the adhesion marker beta4 integrin, which revealed an increase of beta4 integrin segregation in the cell membrane of 50-Hz exposed cells, suggesting that a higher percentage of these cells shows a modified pattern of this adhesion marker.
Asunto(s)
Campos Electromagnéticos/efectos adversos , Queratinocitos/efectos de la radiación , Microscopía de Fuerza Atómica/métodos , Adhesión Celular/efectos de la radiación , Línea Celular Transformada , Membrana Celular/metabolismo , Membrana Celular/efectos de la radiación , Humanos , Integrina beta4/metabolismo , Integrina beta4/efectos de la radiación , Queratinocitos/metabolismo , Queratinocitos/ultraestructura , Microscopía Electrónica de Rastreo/métodosRESUMEN
Human papillomaviruses (HPV) are associated with cervical cancer and interact with growth factors that may enhance malignant transformation of cervical carcinoma cells. Endothelin-1 (ET-1) is released from HPV transfected keratinocytes and induces increased growth response in these cell lines in comparison with normal cells. In the present study several cervical carcinoma cell lines have been analyzed to investigate the expression of ET-1 and its receptors as well as their involvement in tumor growth. All HPV-positive cancer cells secreted ET-1 and expressed mRNA for ET-1 and its receptors, whereas a HPV-negative carcinoma cell line expressed only the ETBR mRNA and didn't secrete ET-1. Binding studies showed that HPV-associated cells expressed an increased number of functional ETAR. ET-1 stimulated a marked dose-dependent increase in [3H]-thymidine incorporation with respect to the normal cells whereas ET-3 and ETBR agonists had no effect. In HPV-positive cancer cells, a specific antagonist of ETAR inhibited the proliferation induced by ET-1 and substantially reduced the basal growth rate of unstimulated cervical tumor cells, whereas the ETBR antagonist had no effect. These results demonstrate that ET-1 participates in the progression of neoplastic growth in HPV-associated carcinoma, in which ETAR are increased and could be targeted for antitumor therapy.
Asunto(s)
Endotelina-1/genética , Papillomaviridae , Receptores de Endotelina/genética , Neoplasias del Cuello Uterino/genética , Antineoplásicos/uso terapéutico , Unión Competitiva/efectos de los fármacos , División Celular/efectos de los fármacos , Línea Celular , Relación Dosis-Respuesta a Droga , Antagonistas de los Receptores de Endotelina , Endotelina-1/metabolismo , Endotelina-1/farmacología , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Oligopéptidos/farmacología , Infecciones por Papillomavirus/genética , Infecciones por Papillomavirus/patología , Infecciones por Papillomavirus/prevención & control , Péptidos Cíclicos/farmacología , Piperidinas/farmacología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Radioinmunoensayo , Receptor de Endotelina A , Receptores de Endotelina/metabolismo , Células Tumorales Cultivadas , Infecciones Tumorales por Virus/genética , Infecciones Tumorales por Virus/patología , Infecciones Tumorales por Virus/prevención & control , Neoplasias del Cuello Uterino/tratamiento farmacológico , Neoplasias del Cuello Uterino/virología , Venenos de Víboras/farmacologíaRESUMEN
Epidemiologic and biomolecular evidence suggests that human papillomavirus (HPV) infection may be associated with the development of head and neck cancers. To clarify the role of HPV in larynx carcinoma, 25 patients were studied for the presence of viral DNA, possible virus integration into the cellular genome, and viral expression both in neoplastic tissues and in neighbouring normal mucosa. Twelve of 25 patients with neoplasia (48%) showed negative results for HPV sequences, and 13 (52%) showed positive results. Among the latter group of patients, seven were HPV-16 positive, five were HPV-6, and one was HPV-45. No multiple infections were detected. The physical status of the HPV genome was analysed by three methods: polymerase chain reaction (PCR), bidimensional agarose gel electrophoresis, and in situ hybridisation. Viral integration into the host genome occurred in 43% of cases of HPV-16 and in 20% of cases of HPV-6. Viral RNA expression was detected by reverse transcription-PCR only in HPV-16-positive tumours. The pattern of expression was consistent with an active role of HPV in cellular transformation. In conclusion, the present work suggests that HPV infection may be involved in some cases of laryngeal carcinoma. However, the transformation mechanisms might be different from those currently accepted for anogenital cancers.
Asunto(s)
Carcinoma de Células Escamosas/virología , Carcinoma Verrugoso/virología , Proteínas de Unión al ADN , Mucosa Laríngea/virología , Neoplasias Laríngeas/virología , Proteínas Oncogénicas Virales/genética , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/virología , Infecciones Tumorales por Virus/virología , Adulto , Anciano , Carcinoma de Células Escamosas/patología , Carcinoma Verrugoso/patología , ADN Viral/análisis , Femenino , Expresión Génica , Humanos , Mucosa Laríngea/patología , Neoplasias Laríngeas/patología , Masculino , Persona de Mediana Edad , Papillomaviridae/clasificación , Papillomaviridae/genética , Infecciones por Papillomavirus/patología , ARN Mensajero , ARN Viral/análisis , Infecciones Tumorales por Virus/patología , Integración ViralRESUMEN
This paper shows that cocaine amplifies Epstein-Barr virus (EBV) reactivation in Raji cells. Its effect on early viral protein synthesis was maximal when it was added with 12-O-tetradecanoyl phorbol-13-acetate (TPA) plus n-butyrate, but nil when added alone. The enhancing effect of cocaine on early replicative stages of latent EBV was associated with an increase of Ca(2+) mobilization induced by the drug and with an induction of cellular protein phosphorylation in chemicals and cocaine-treated Raji cells. Cocaine also acted synergistically with TPA and n-butyrate to induce Z Epstein-Barr replication activator (ZEBRA), a nuclear phosphoprotein responsible for the activation of early viral gene expression. These findings provide the first evidence that cocaine may represent an important co-factor in the reactivation of early stages of latent EBV infection.
Asunto(s)
Cocaína/farmacología , Herpesvirus Humano 4/efectos de los fármacos , Proteínas Virales , Latencia del Virus/efectos de los fármacos , Replicación Viral/efectos de los fármacos , Transporte Biológico/efectos de los fármacos , Butiratos/farmacología , Calcio/metabolismo , Carcinógenos/farmacología , Proteínas de Unión al ADN/biosíntesis , Sinergismo Farmacológico , Herpesvirus Humano 4/fisiología , Humanos , Fosforilación/efectos de los fármacos , Acetato de Tetradecanoilforbol/farmacología , Transactivadores/biosíntesis , Células Tumorales CultivadasRESUMEN
Apoptosis, or 'programmed cell death' is a process of general biological relevance with implications in several physiological and pathological conditions of the skin. However, little is known about its induction in keratinocytes by regulator agents. In this work we demonstrate that IFNbeta, but not IFNalpha, selectively induces programmed cell death in HPK-Ia cells, a line derived from human keratinocytes transformed with HPV-16 DNA. This IFNbeta-triggered apoptosis is strictly dependent on a serum-induced partially differentiated phenotype; it occurs through the activation of a check point in the early 'S' phase, where the cells are arrested and eventually driven to apoptosis. These data indicate that apoptosis may be induced in keratinocytes by a regulator agent combined with a differentiating stimulus.
Asunto(s)
Antivirales/farmacología , Apoptosis/efectos de los fármacos , Transformación Celular Viral , Interferón beta/farmacología , Queratinocitos/efectos de los fármacos , Recuento de Células/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Línea Celular , Línea Celular Transformada , ADN/efectos de los fármacos , ADN/metabolismo , Fragmentación del ADN/efectos de los fármacos , Humanos , Interferón-alfa/farmacología , Interferón gamma/farmacología , Queratinocitos/citología , Queratinocitos/virología , PapillomaviridaeRESUMEN
Human keratinocytes express ETA receptors and produce endothelin-1 (ET-1), which stimulates growth response. Previously, we reported that a twofold increase in ETA receptors is present in human papillomavirus type 16 (HPV16) immortalized keratinocytes and that ET-1 induces enhanced proliferative response in these cell lines compared to normal cells. The present studies examine whether the E5 gene of HPV16 is responsible for the enhanced activity of ET-1 in HPV-transfected keratinocytes. The presence of the E5 gene in growth factor-starved keratinocytes induced the DNA synthesis and enhanced the mitogenic activity of ET-1 or epidermal growth factor. The selection of primary keratinocytes in growth factor-free medium with the addition of ET-1 as a growth factor showed that E5-transfected keratinocytes were able to grow and to form a higher number of larger colonies with respect to untransfected cells. This effect seems to be related to the interaction of E5 with the mitogenic signaling pathway of ET-1 rather than to an increase in the expression of the receptors for ET-1. In conclusion, our data demonstrate that E5 enhances ligand signaling in keratinocytes outside the EGF pathway by the amplification of the proliferative effect of ET-1/ETA receptor signaling.
Asunto(s)
Endotelina-1/farmacología , Queratinocitos/citología , Queratinocitos/virología , Proteínas Oncogénicas Virales/fisiología , Papillomaviridae/fisiología , Receptores de Endotelina/fisiología , División Celular/efectos de los fármacos , Línea Celular , Antagonistas de los Receptores de Endotelina , Factor de Crecimiento Epidérmico/farmacología , Humanos , Queratinocitos/efectos de los fármacos , Proteínas Oncogénicas Virales/biosíntesis , Péptidos Cíclicos/farmacología , Reacción en Cadena de la Polimerasa , Receptor de Endotelina A , Receptores de Endotelina/biosíntesis , Proteínas Recombinantes/biosíntesis , TransfecciónRESUMEN
Papillomatous lesions were isolated from the mammary skin of goats and examined for evidence of papillomavirus (PV) infection by various criteria, including gross morphology, histology and DNA hybridization. Although some lesions showed gross papillomatous morphological and histological features similar to those caused by papillomavirus in other species, no viral particles were detected. Reverse slot hybridization revealed cross-hybridization between DNA extracted from goat mammary papillomas and human papillomaviruses (HPV). Southern blot, using ovine papillomavirus (OPV) and bovine papillomavirus type 5 (BPV 5) DNA probes under conditions of reduced stringency (Tm -40 degrees C), detected homologous sequences in 40% of the biopsies. DNA fragments corresponding probably to a monomeric form (7000-8000 bp) of an unknown papillomavirus genome were detected. This study provides evidence for the existence of papillomavirus-like sequences in caprine mammary papillomas and suggests that a papillomavirus is likely to be involved in the development of precancerous lesions of goat mammary skin.