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1.
Clin Radiol ; 72(3): 265.e7-265.e23, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27889090

RESUMEN

AIM: To report the authors' experience of focal nodular haematopoietic marrow hyperplasia (FNHMH) and diffuse haematopoietic marrow hyperplasia (DHMH) clinically masquerading as skip, distant, or disseminated metastasis in seven patients with underlying malignant neoplasms. MATERIALS AND METHODS: Five patients with FNHMH and two with DHMH mistaken radiologically as skip and disseminated metastasis, respectively, were compared and contrasted with four patients with osteosarcomas and two with chondrosarcomas harbouring skip metastasis, noting the temporal relationship with their haematological profile. RESULTS: FNHMH and DHMH were undetectable by plain radiography and computed tomography (CT) except one showing subtle sclerosis on CT. They showed either isointense or hyperintense, but not hypointense, attenuation at T1-weighted imaging, and all showed hyperintense attenuation at T2-weighted MRI relative to skeletal muscle. Of the five patients who underwent bone scintigraphy, one showed mildly increased uptake, and one out of two showed markedly increased 2-[18F]-fluoro-2-deoxy-d-glucose (FDG)-positron-emission tomography (PET) uptake. The rates for sarcoma skip metastasis by plain radiography, CT, MRI, and bone scintigraphy were 40%, 66.7%, 100%, and 66.7%, respectively. At MRI, 60% showed hypointense and 40% isointense attenuation at T1-weighted, 80% hyperintense and 20% hypointense attenuation at T2-weighted imaging. Combined FDG-PET and CT, which was performed in only one patient, failed to show the skip metastasis. Not every patient with FNHMH or DHMH received granulocyte colony-stimulating factor (GCSF), but all had low or falling haemoglobin levels, which may thus be the prime cause for HMH. CONCLUSIONS: Due to overlapping radiological features, FNHMH and DHMH are great radiological mimics of malignancy. In some cases, needle biopsy is required for their definitive differentiation.


Asunto(s)
Neoplasias de la Médula Ósea/sangre , Neoplasias de la Médula Ósea/diagnóstico por imagen , Diagnóstico por Imagen/métodos , Neoplasias Hematológicas/sangre , Neoplasias Hematológicas/diagnóstico por imagen , Hemoglobinas/análisis , Adolescente , Adulto , Niño , Diagnóstico Diferencial , Errores Diagnósticos/prevención & control , Reacciones Falso Negativas , Neoplasias Hematológicas/complicaciones , Humanos , Masculino , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
2.
Oncogene ; 36(9): 1245-1255, 2017 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-27546620

RESUMEN

Liver kinase B1 (LKB1) is mutationally inactivated in Peutz-Jeghers syndrome and in a variety of cancers including human papillomavirus (HPV)-caused cervical cancer. However, the significance of LKB1 mutations in cervical cancer initiation and progress has not been examined. Herein, we demonstrated that, in mouse embryonic fibroblasts, loss of LKB1 and transduction of HPV16 E6/E7 had an additive effect on constraining cell senescence while promoting cell proliferation and increasing glucose consumption, lactate production and ATP generation. Knockdown of LKB1 increased and ectopic expression of LKB1 decreased glycolysis, anchorage-independent cell growth, and cell migration and invasion in HPV-transformed cells. In the tumorigenesis and lung metastasis model in syngeneic mice, depletion of LKB1 markedly increased tumor metastatic colonies in lungs without affecting subcutaneous tumor growth. We showed that HPV16 E6/E7 enhanced the expression of hexokinase-ll (HK-II) in the glycolytic pathway through elevated c-MYC. Ectopic LKB1 reduced HK-II along with glycolysis. The inverse relationship between HK-II and LKB1 was also observed in normal and HPV-associated cervical lesions. We propose that LKB1 acts as a safeguard against HPV-stimulated aerobic glycolysis and tumor progression. These findings may eventually aid in the development of therapeutic strategy for HPV-associated malignancies by targeting cell metabolism.


Asunto(s)
Transformación Celular Neoplásica/metabolismo , Glucosa/metabolismo , Glucólisis/fisiología , Infecciones por Papillomavirus/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Neoplasias del Cuello Uterino/metabolismo , Neoplasias del Cuello Uterino/patología , Quinasas de la Proteína-Quinasa Activada por el AMP , Animales , Apoptosis , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Estudios de Casos y Controles , Proliferación Celular , Transformación Celular Neoplásica/patología , Femenino , Estudios de Seguimiento , Hexoquinasa/genética , Hexoquinasa/metabolismo , Papillomavirus Humano 16/fisiología , Humanos , Ratones , Ratones Endogámicos C57BL , Estadificación de Neoplasias , Proteínas Oncogénicas Virales/genética , Proteínas Oncogénicas Virales/metabolismo , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Infecciones por Papillomavirus/patología , Infecciones por Papillomavirus/virología , Pronóstico , Proteínas Serina-Treonina Quinasas/genética , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Células Tumorales Cultivadas , Neoplasias del Cuello Uterino/virología
3.
Insights Imaging ; 1(3): 149-153, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22347912

RESUMEN

PURPOSE: The objective of this study was to describe the sonographic features of deep-seated lipomas. METHODS: A retrospective review of the sonographic features of 64 deep seated lipomas in 64 patients (43 females, 21 males, mean age 46.5, range 16-77 years) seen over an 8-year period (1998-2006) was undertaken. RESULTS: Features evaluated were location, size, shape, marginal definition, internal echogenicity, including the presence of intermingled muscle fibres and linear internal echoes, acoustic transmission and vascularity. Confirmation was histological in 37 (58%) cases and by typical magnetic resonance imaging (MRI) appearance in 27 (42%) cases. CONCLUSION: The results show that although the features of deep-seated lipoma are more variable than those reported for subcutaneous lipomas, the presence of thin internal echoes in conjunction with other less specific features should enable a correct diagnosis.

5.
Clin Radiol ; 59(4): 369-75, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15041458

RESUMEN

AIM: To investigate whether analysing vascularity of soft-tissue tumours on ultrasound assists differentiating benign from malignant tumours. MATERIALS AND METHODS: One hundred and forty-eight vascular soft-tissue tumours in 148 patients (88 males, mean age 45.6 years) were studied. Final diagnosis was established histologically in 95 (64%) of cases. For each tumour, three-colour Doppler imaging features (vascularity, vascular density, vascular organization) and 13 pulsed Doppler (spectral analysis) parameters were assessed. Data analysis was performed to isolate optimal discriminatory criteria for differentiating benign from malignant tumours. RESULTS: Significantly more benign soft-tissue tumours had an organized vascular pattern on colour Doppler imaging. If the vascular pattern is organized, this is a good indicator of tumour benignity. However, this pattern was apparent in less then one-third of the soft-tissue tumours. Benign tumours also had significantly higher minimum end diastolic velocity (EDVmin) and lower mean ratio of resistive index (RImean) than malignant soft-tissue tumours, though considerable overlap existed between the two groups. CONCLUSION: Colour Doppler imaging analysis of soft-tissue tumours is of limited value when differentiating benign from malignant tumours. If an organized vascular pattern is present, the tumour is more likely to be benign. Flow characteristics were not specific enough to be applicable in clinical practice.


Asunto(s)
Neoplasias de los Tejidos Blandos/irrigación sanguínea , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Neoplasias de los Tejidos Blandos/diagnóstico por imagen , Neoplasias de los Tejidos Blandos/patología , Ultrasonografía Doppler en Color
6.
J Clin Pathol ; 57(3): 256-9, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-14990595

RESUMEN

BACKGROUND: Severe acute respiratory syndrome (SARS) is a newly described form of atypical pneumonia linked to a novel coronavirus. AIMS: To review the sputum cytology of 15 patients who fulfilled the World Health Organisation clinical criteria for SARS in an attempt to evaluate whether early diagnosis is feasible with routine sputum examination. METHODS: All sputum samples from patients with SARS from the four major hospitals in Hong Kong were reviewed; abnormalities were sought in the cellular component, including abnormal numbers and morphology of the component cells compared with those from age matched controls taken over the same period one year ago. RESULTS: Fifteen sputum samples from patients were compared with 25 control samples. In the patients with SARS, loose aggregates of macrophages were seen more frequently in the sputum. These macrophages frequently showed morphological changes, such as cytoplasmic foaminess, vacuole formation, and nuclear changes (including multinucleation and a ground glass appearance) when compared with the control samples. CONCLUSIONS: The cytological features of SARS are non-specific, but the observation of any of the described features should prompt further investigations, especially in patients with suspicious clinical features.


Asunto(s)
Síndrome Respiratorio Agudo Grave/patología , Esputo/citología , Adulto , Anciano , Núcleo Celular/patología , Citoplasma/patología , Femenino , Humanos , Pulmón/patología , Macrófagos/patología , Masculino , Persona de Mediana Edad , Vacuolas/patología
8.
J Clin Pathol ; 57(1): 90-4, 2004 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-14693846

RESUMEN

Sclerosing epithelioid fibrosarcoma is a rare tumour characterised histologically by a predominant population of epithelioid cells arranged in strands and nests, embedded in a fibrotic and hyalinised stroma. It is a low grade tumour with an indolent course. A 48 year old woman presented with a painful swelling over her back for six months. Investigation and biopsy revealed features of sclerosing epithelioid fibrosarcoma involving the left half of the sacrum, left sacro-iliac joint, and posterior part of the left ilium. Preoperative radiotherapy and wide location excision of the tumour were followed by metastatic recurrence of the tumour in the lung and scalp six years after initial presentation. The tumour showed typical histology of sclerosing epithelioid fibrosarcoma. The radiological features confirmed its primary location in the sacrum. The patient declined chemotherapy and died of disseminated disease eight years after initial presentation. Review of the literature confirms the fact that sclerosing epithelioid fibrosarcoma, despite its low grade, is a clinicopathologically distinct tumour with full malignant potential, the recurrence, metastasis, and mortality rate being 48%, 60%, and 35%, respectively. Sclerosing epithelioid fibrosarcoma can occur as a primary bone tumour, the clinical behaviour of which is probably similar to its soft tissue counterpart.


Asunto(s)
Fibrosarcoma/patología , Sacro , Neoplasias de la Columna Vertebral/patología , Resultado Fatal , Femenino , Fibrosarcoma/diagnóstico por imagen , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Radiografía , Neoplasias de la Columna Vertebral/diagnóstico por imagen
9.
Scand J Rheumatol ; 32(5): 306-8, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14690145

RESUMEN

We describe a Chinese woman who developed severe heart failure 3 years from the onset of systemic lupus erythematosus (SLE). Endomyocardial biopsy confirmed lupus myocarditis, with focal infiltrates of small lymphocytes and some polymorphic neutrophils. The conventional treatment for cardiac failure plus oral prednisolone failed to bring clinical and echocardiographical improvement until the addition of intravenous (i.v.) 'pulse' cyclophosphamide. Three weeks after i.v. cyclophosphamide treatment, there was significant improvement of her heart failure symptoms with improvement in the ejection fraction from 19% to 63%.


Asunto(s)
Ciclofosfamida/uso terapéutico , Inmunosupresores/uso terapéutico , Lupus Eritematoso Sistémico/tratamiento farmacológico , Miocarditis/tratamiento farmacológico , Adulto , Ciclofosfamida/administración & dosificación , Femenino , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/patología , Humanos , Inmunosupresores/administración & dosificación , Inyecciones Intravenosas , Lupus Eritematoso Sistémico/etiología , Lupus Eritematoso Sistémico/patología , Miocarditis/etiología , Miocarditis/patología , Miocardio/patología , Resultado del Tratamiento
10.
Life Sci ; 73(11): 1427-36, 2003 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-12850503

RESUMEN

This study aims to investigate the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) in giant cell tumor of bone (GCT) and other osteolytic lesions in bone. By using semi-quantitative RT-PCR, we showed that three major isoforms of VEGF (121, 165 and 189) were expressed in GCTs, with isoform 121 being the most abundant. The expression levels of VEGF and MMP-9 mRNA were significantly higher in advanced GCTs (stage II/III) than in stage I GCTs. We further elucidated the cellular localization of VEGF and MMP-9 gene transcripts in GCT and other osteolytic lesions using an in situ hybridization assay. The results showed that stromal tumor cells and osteoclast-like giant cells of GCT, fibrous stromal cells in anuerysmal bone cysts and fibrous dysplasia, and Langerhans-type giant cells as well as histocytes in eosinophillic granuloma, were all strongly positive for VEGF and MMP-9 mRNA expression. In a prospective study, we performed VEGF and MMP-9 immuno-staining on paraffin sections of pathological tissues harvested from 48 patients (14 GCT, 10 anuerysmal bone cysts, 10 eosinophillic granuloma, 4 fibrous dysplasia, 2 simple bone cyst, 2 osteomyelitis and 6 patients with fractured femoral head as control). The results showed that the differences in VEGF and MMP-9 expression between Stage I and other advanced Stages (II, III and recurrent) were highly significant (p<0.001), with advanced stages showing a higher mean expression. The difference between recurrent and Stage II and III lesions, was also statistically significant (p=0.03 for VEGF, and p=0.01 for MMP-9 expression), with recurrent lesions showing a higher mean expression of both VEGF and MMP-9. In conclusion, VEGF and MMP-9 expression in osteolytic lesions of bone co-relates well with the extent of bone destruction and local recurrence. Their expression may therefore provide some prognostic indication of the possible aggressive behavior of the underlying pathology.


Asunto(s)
Neoplasias Óseas/química , Factores de Crecimiento Endotelial/genética , Tumor Óseo de Células Gigantes/química , Péptidos y Proteínas de Señalización Intercelular/genética , Linfocinas/genética , Metaloproteinasa 9 de la Matriz/genética , Osteólisis/metabolismo , Quistes Óseos/metabolismo , Quistes Óseos Aneurismáticos/metabolismo , Neoplasias Óseas/patología , Factores de Crecimiento Endotelial/análisis , Displasia Fibrosa Ósea/metabolismo , Expresión Génica , Tumor Óseo de Células Gigantes/patología , Granuloma/metabolismo , Histiocitos/química , Humanos , Inmunohistoquímica , Hibridación in Situ , Péptidos y Proteínas de Señalización Intercelular/análisis , Linfocinas/análisis , Metaloproteinasa 9 de la Matriz/análisis , Recurrencia Local de Neoplasia , Estadificación de Neoplasias , Osteoclastos/química , Osteomielitis/metabolismo , Estudios Prospectivos , Isoformas de Proteínas/genética , ARN Mensajero/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células del Estroma/química , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial Vascular
11.
Mol Pathol ; 56(2): 116-20, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12665629

RESUMEN

AIMS: Chondroblastoma is a rare, locally aggressive bone tumour that causes osteolytic destruction at the epiphyseal end of the affected bone. It is possible that tumour cells may stimulate osteoclastogenesis and osteolytic destruction through the production of receptor activator of NF-kappaB ligand (RANKL), which is a key molecule essential for regulating osteoclast formation and activity. Therefore, the expression of RANKL at both the mRNA and the protein level was investigated in chondroblastoma tumour tissue obtained from patients. METHODS: The expression of RANKL gene transcripts was analysed by the reverse transcription-polymerase chain reaction (RT-PCR), and the cellular localisation of RANKL mRNA and protein was demonstrated by means of in situ hybridisation and immunohistochemistry. RESULTS: RT-PCR analysis indicated that RANKL mRNA was present in all chondroblastoma specimens and normal cancellous bone samples, but not in normal articular cartilage and chondrosarcoma tissues. In contrast, gene transcripts of osteoprotegerin (OPG), the decoy receptor of RANKL, were detected in all types of tissues. The chondroid origin of neoplastic mononuclear cells in chondroblastoma was confirmed by positive S-100 immunohistochemical staining. Both RANKL mRNA and protein were exclusively expressed in these neoplastic mononuclear cells. CONCLUSIONS: These findings suggest that RANKL may be involved in the tumour cell induced recruitment of osteoclast-like cells and consequent osteolytic bone destruction in chondroblastoma.


Asunto(s)
Neoplasias Óseas/metabolismo , Proteínas Portadoras/metabolismo , Condroblastoma/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas de Neoplasias/metabolismo , Adolescente , Adulto , Neoplasias Óseas/patología , Proteínas Portadoras/genética , Proteínas Portadoras/fisiología , Niño , Condroblastoma/patología , Femenino , Expresión Génica , Humanos , Técnicas para Inmunoenzimas , Ligandos , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/fisiología , FN-kappa B/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/fisiología , Osteoclastos/fisiología , Ligando RANK , ARN Mensajero/genética , ARN Neoplásico/genética , Receptor Activador del Factor Nuclear kappa-B , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
12.
Br J Radiol ; 76(904): 264-7, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12711647

RESUMEN

Paraffinoma of breast is a recognized complication of paraffin injection for breast augmentation. Liquid paraffin can extend along fascial planes to involve adjacent tissues. A rare case of paraffinoma in anterior abdominal wall, which was misdiagnosed as a soft tissue liposarcoma before surgical excision, is reported. It was heterogeneous with marked posterior acoustic shadowing and small peripheral cysts on ultrasound. On MRI, it had ill-defined margins and was heterogeneous in signal intensity. Small round components which were hypointense on all sequences were demonstrated. There is significant overlapping of imaging features between paraffinoma and soft tissue liposarcoma. Histological differentiation from well-differentiated liposarcoma may also be difficult. A detailed clinical history of previous paraffin injection for breast augmentation is very important for correct interpretation of imaging and histopathological findings.


Asunto(s)
Pared Abdominal , Granuloma de Cuerpo Extraño/diagnóstico , Liposarcoma/diagnóstico , Parafina/efectos adversos , Neoplasias de los Tejidos Blandos/diagnóstico , Adulto , Diagnóstico Diferencial , Extravasación de Materiales Terapéuticos y Diagnósticos/complicaciones , Femenino , Granuloma de Cuerpo Extraño/etiología , Humanos , Imagen por Resonancia Magnética , Mamoplastia/efectos adversos
15.
Anat Rec ; 264(2): 169-82, 2001 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-11590594

RESUMEN

In order to study the changes in the pattern of autonomic innervation of the human cardiac conduction system in relation to age, the innervation of the conduction system of 24 human hearts (the age of the individuals ranged from newborn to 80 years), freshly obtained at autopsy, was evaluated by a combination of immunofluorescence and histochemical techniques. The pattern of distribution and density of nerves exhibiting immunoreactivity against protein gene product 9.5 (PGP), a general neural marker, dopamine beta-hydroxylase (DBH) and tyrosine hydroxylase (TH), indicators for presumptive sympathetic neural tissue, and those demonstrating positive acetylcholinesterase (AChE) activity, were studied. All these nerves showed a similar pattern of distribution and developmental changes. The density of innervation, assessed semiquantitatively, was highest in the sinus node, and exhibited a decreasing gradient through the atrioventricular node, penetrating and branching bundle, to the bundle branches. Other than a paucity of those showing AChE activity, nerves were present in substantial quantities in infancy. They then increased in density to a maximum in childhood, at which time the adult pattern was achieved and then gradually decreased in density in the elders to a level similar to or slightly less than that in infancy. In contrast, only scattered AChE-positive nerves were found in the sinus and atrioventricular nodes, but were absent from the bundle branches of the infant heart, whereas these conduction tissues themselves possessing a substantial amount of pseudocholinesterase. During maturation into adulthood, however, the conduction tissues gradually lost their content of pseudocholinesterase but acquired a rich supply of AChE-positive nerves, comparable in density to those of DBH and TH nerves. The decline in density of AChE-positive nerves in the conduction tissues in the elders was also similar to those of DBH and TH nerves. Our findings of initial sympathetic dominance in the neural supply to the human cardiac conduction system in infancy, and its gradual transition into a sympathetic and parasympathetic codominance in adulthood, correlate well with the physiologic alterations known to occur in cardiac rate during postnatal development. The finding of reduction in density of innervation of the conduction tissue with ageing is also in agreement with clinical and electrophysiological findings such as age-associated reduction in cardiac response to parasympathetic stimulation. Finally, our findings also support the hypothesis that, in addition to the para-arterial route, the parafascicular route of extension along the conduction tissue constitutes another pathway for the innervation of the conduction system of the human heart during development.


Asunto(s)
Envejecimiento/fisiología , Vías Autónomas/anatomía & histología , Vías Autónomas/crecimiento & desarrollo , Sistema de Conducción Cardíaco/anatomía & histología , Sistema de Conducción Cardíaco/crecimiento & desarrollo , Acetilcolinesterasa/análisis , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Vías Autónomas/química , Niño , Preescolar , Dopamina beta-Hidroxilasa/análisis , Femenino , Técnica del Anticuerpo Fluorescente , Corazón , Sistema de Conducción Cardíaco/química , Humanos , Inmunohistoquímica , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Fibras Nerviosas/química , Tioléster Hidrolasas/análisis , Tirosina 3-Monooxigenasa/análisis , Ubiquitina Tiolesterasa
16.
J Virol ; 75(16): 7602-11, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11462032

RESUMEN

Replication-competent adenoviruses are being investigated as potential anticancer agents. Exclusive virus replication in cancer cells has been proposed as a safety trait to be considered in the design of oncolytic adenoviruses. From this perspective, we have investigated several adenovirus mutants for their potential to conditionally replicate and promote the killing of cells expressing human papillomavirus (HPV) E6 and E7 oncoproteins, which are present in a high percentage of anogenital cancers. For this purpose, we have employed an organotypic model of human stratified squamous epithelium derived from primary keratinocytes that have been engineered to express HPV-18 oncoproteins stably. We show that, whereas wild-type adenovirus promotes a widespread cytopathic effect in all infected cells, E1A- and E1A/E1B-deleted adenoviruses cause no deleterious effect regardless of the coexpression of HPV18 E6E7. An adenovirus deleted in the CR2 domain of E1A, necessary for binding to the pRB family of pocket proteins, shows no selectivity of replication as it efficiently kills all normal and E6E7-expressing keratinocytes. Finally, an adenovirus mutant deleted in the CR1 and CR2 domains of E1A exhibits preferential replication and cell killing in HPV E6E7-expressing cultures. We conclude that the organotypic keratinocyte culture represents a distinct model to evaluate adenovirus selectivity and that, based on this model, further modifications of the adenovirus genome are required to restrict adenovirus replication to tumor cells.


Asunto(s)
Adenoviridae/fisiología , Queratinocitos/virología , Papillomaviridae/fisiología , Células Cultivadas , Regulación Viral de la Expresión Génica , Humanos , Mutación , Replicación Viral
17.
Cancer Res ; 61(12): 4858-63, 2001 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-11406563

RESUMEN

We have demonstrated previously that oncogenic human papillomaviruses (HPVs) induce basal cell tetrasomy in low-grade squamous intraepithelial lesions of the cervix. To identify HPV genes and growth conditions involved in this process, we analyzed: (a) organotypic raft cultures of primary human keratinocytes transfected with whole HPV-18 genomes; and (b) organotypic raft cultures acutely infected with recombinant retroviruses expressing the HPV-18 E6, E7, or E6/E7 genes from the differentiation-dependent HPV-18 enhancer-promoter. Cultures were examined for HPV DNA by in situ hybridization and for karyotype by interphase cytogenetics. Tetrasomy occurred in the suprabasal strata of raft cultures expressing E7 and E6/E7 but not in those expressing E6 alone or in a control culture. These data indicate that suprabasal tetrasomy occurs in association with expression of the E7 gene alone. Basal cell tetrasomy was additionally observed in the raft culture transfected with whole HPV-18 genomes, consistent with observations in low-grade squamous intraepithelial lesions. The distribution of tetrasomic cells in these raft cultures may reflect the involvement of additional viral genes or possibly differences in the pattern of viral oncogene and host gene expression.


Asunto(s)
Aberraciones Cromosómicas , Proteínas de Unión al ADN , Queratinocitos/virología , Proteínas Oncogénicas Virales/genética , Papillomaviridae/genética , Células del Tejido Conectivo , Replicación del ADN , ADN Viral/biosíntesis , ADN Viral/genética , Expresión Génica , Humanos , Hibridación in Situ , Queratinocitos/fisiología , Queratinocitos/ultraestructura , Proteínas Oncogénicas Virales/biosíntesis , Transfección
18.
J Virol ; 75(13): 6121-34, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11390614

RESUMEN

The human papillomavirus (HPV) E7 protein promotes S-phase reentry in a fraction of postmitotic, differentiated keratinocytes. Here we report that these cells contain an inherent mechanism that opposes E7-induced DNA replication. In organotypic raft cultures of primary human keratinocytes, neither cyclin E nor p21cip1 is detectable in situ. However, E7-transduced differentiated cells not in S phase accumulate abundant cyclin E and p21cip1. We show that normally p21cip1 protein is rapidly degraded by proteasomes. In the presence of E7 or E6/E7, p21cip1, cyclin E, and cyclin E2 proteins were all up-regulated. The accumulation of p21cip1 protein is a posttranscriptional event, and ectopic cyclin E expression was sufficient to trigger it. In constract, cdk2 and p27kip1 were abundant in normal differentiated cells and were not significantly affected by E7. Cyclin E, cdk2, and p21cip1 or p27kip1 formed complexes, and relatively little kinase activity was found associated with cyclin E or cdk2. In patient papillomas and E7 raft cultures, all p27kip1-positive cells were negative for bromodeoxyuridine (BrdU) incorporation, but only some also contained cyclin E and p21cip1. In contrast, all cyclin E-positive cells also contained p27kip1. When the expression of p21cip1 was reduced by rottlerin, a PKC delta inhibitor, p27kip1- and BrdU-positive cells remained unchanged. These observations show that high levels of endogenous p27kip1 can prevent E7-induced S-phase reentry. This inhibition then leads to the stabilization of cyclin E and p21cip1. Since efficient initiation of viral DNA replication requires cyclin E and cdk2, its inhibition accounts for heterogeneous viral activities in productively infected lesions.


Asunto(s)
Acetilcisteína/análogos & derivados , Ciclina E/fisiología , Ciclinas/metabolismo , Proteínas de Unión al ADN , Queratinocitos/metabolismo , Proteínas Oncogénicas Virales/fisiología , Acetofenonas/farmacología , Acetilcisteína/farmacología , Animales , Benzopiranos/farmacología , Ciclina E/análisis , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Ciclinas/análisis , Ciclinas/química , Cisteína Endopeptidasas/fisiología , Humanos , Recién Nacido , Complejos Multienzimáticos/fisiología , Complejo de la Endopetidasa Proteasomal , Proteína Quinasa C/fisiología , Conejos
19.
Dev Biol (Basel) ; 106: 367-73, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11761250

RESUMEN

Papillomaviruses are ubiquitous pathogens of humans and other vertebrates. Productive infections lead to hyperproliferative lesions in squamous epithelia from diverse anatomic sites, both cutaneous and mucosal. The 7,900 bp double-stranded, circular DNA genome replicates as extrachromosomal plasmids in the nuclei of infected cells. The productive phase of the HPV infection takes place in differentiated, post-mitotic squamous keratinocytes. However, viral DNA replication requires the host cells to supply much of the replication machinery and substrates. Consequently, these viruses usurp the cellular control mechanisms via protein interactions and provide an excellent model system to investigate cellular processes. This paper summarize our investigations and insight into the virus-host interactions observed in productively infected patient lesions, in a model organotypic culture system of primary human keratinocytes transduced with viral genes, and in a cell-free viral DNA replication system with purified viral and host protein.


Asunto(s)
Replicación del ADN/fisiología , ADN Viral/biosíntesis , Papillomaviridae/fisiología , Humanos , Papillomaviridae/crecimiento & desarrollo
20.
Dev Biol (Basel) ; 106: 381-5, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11761253

RESUMEN

Infection by the oncogenic human papillomavirus (HPV) types 16 and type 18 can progress to cancers. Two well studied cervical carcinoma cell lines, SiHa and CaSki, contain two to four copies, or several hundred copies of integrated HPV-16, respectively. To define the chromosomal loci from which HPV mRNAs are transcribed in these cells, we have simultaneously visualized chromosomal DNA territories, HPV DNA or nascent HPV RNA sequences by using a highly sensitive in situ hybridization (T-FISH) technique employing deposition of fluorescent tyramides. We found that, in SiHa cells, nascent HPV RNAs co-localized with both integrated HPV copies on chromosome 13. Surprisingly, in CaSki cells, nascent HPV RNA only co-localized with one minor HPV DNA-positive locus on chromosome 14. The DNA signal intensity of this locus was consistent with a single to a few HPV intergrants. The tyramide methodologies described here provide an in-depth molecular cytological analyses applicable to research and diagnosis.


Asunto(s)
Amidas/química , ADN Viral/genética , Hibridación Fluorescente in Situ/métodos , Papillomaviridae/genética , Transcripción Genética , ARN Viral/genética
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