Assuntos
Povo Asiático/genética , Códon sem Sentido/genética , Síndromes Neoplásicas Hereditárias/diagnóstico , Síndromes Neoplásicas Hereditárias/genética , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/genética , Proteínas Supressoras de Tumor/genética , Enzima Desubiquitinante CYLD , Feminino , HumanosAssuntos
Mutação de Sentido Incorreto/genética , Esclerose Tuberosa/genética , Proteínas Supressoras de Tumor/genética , Adolescente , Povo Asiático , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Esclerose Tuberosa/patologia , Proteína 1 do Complexo Esclerose Tuberosa , Proteína 2 do Complexo Esclerose Tuberosa , Adulto JovemRESUMO
Expression of the PMLRARalpha fusion dominant-negative oncogene in the epidermis of transgenic mice resulted in spontaneous skin tumors attributed to changes in both the PML and RAR pathways [Hansen et al., Cancer Res 2003; 63:5257-5265]. To determine the contribution of PML to skin tumor susceptibility, transgenic mice were generated on an FVB/N background, that overexpressed the human PML protein in epidermis and hair follicles under the control of the bovine keratin 5 promoter. PML was highly expressed in the epidermis and hair follicles of these mice and was also increased in cultured keratinocytes where it was confined to nuclear bodies. While an overt skin phenotype was not detected in young transgenic mice, expression of keratin 10 (K10) was increased in epidermis and hair follicles and cultured keratinocytes. As mice aged, they exhibited extensive alopecia that was accentuated on the C57BL/6J background. Following skin tumor induction with 7, 12-dimethylbenz[a]anthracene (DMBA) as initiator and 12-O-tetradecanoylphorbol-13-acetate (TPA) as promoter, papilloma multiplicity and size were decreased in the transgenic mice by 35%, and the conversion of papillomas to carcinomas was delayed. Cultured transgenic keratinocytes underwent premature senescence and upregulated transcripts for p16 and Rb but not p19 and p53. Together, these changes suggest that PML participates in regulating the growth and differentiation of keratinocytes that likely influence its activity as a suppressor for tumor development.
Assuntos
Genes Supressores de Tumor , Proteínas Nucleares/fisiologia , Neoplasias Cutâneas/genética , Fatores de Transcrição/fisiologia , Proteínas Supressoras de Tumor/fisiologia , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Animais , Sequência de Bases , Carcinógenos/toxicidade , Primers do DNA , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Nucleares/genética , Reação em Cadeia da Polimerase , Proteína da Leucemia Promielocítica , Neoplasias Cutâneas/induzido quimicamente , Acetato de Tetradecanoilforbol/toxicidade , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genéticaRESUMO
The region of conserved synteny on mouse chromosome 11/human 17q11-q21 is known to carry a susceptibility gene(s) for intramacrophage pathogens. The region is rich in candidates including NOS2A, CCL2/MCP-1, CCL3/MIP-1alpha, CCL4/MIP-1beta, CCL5/RANTES, CCR7, STAT3 and STAT5A/5B. To examine the region in man, we studied 92 multicase tuberculosis (627 individuals) and 72 multicase leprosy (372 individuals) families from Brazil. Multipoint nonparametric analysis (ALLEGRO) using 16 microsatellites shows two peaks of linkage for leprosy at D17S250 (Z(lr) score 2.34; P=0.01) and D17S1795 (Z(lr) 2.67; P=0.004) and a single peak for tuberculosis at D17S250 (Z(lr) 2.04; P=0.02). Combined analysis shows significant linkage (peak Z(lr) 3.38) at D17S250, equivalent to an allele sharing LOD score 2.48 (P=0.0004). To determine whether one or multiple genes contribute, 49 informative single nucleotide polymorphisms were typed in candidate genes. Family-based allelic association testing that was robust to family clustering demonstrated significant associations with tuberculosis susceptibility at four loci separated by intervals (NOS2A-8.4 Mb-CCL18-32.3 kb-CCL4-6.04 Mb-STAT5B) up to several Mb. Stepwise conditional logistic regression analysis using a case/pseudo-control data set showed that the four genes contributed separate main effects, consistent with a cluster of susceptibility genes across 17q11.2.
Assuntos
Cromossomos Humanos Par 17/genética , Predisposição Genética para Doença , Hanseníase/genética , Proteínas do Leite , Tuberculose/genética , Animais , Brasil , Estudos de Casos e Controles , Quimiocina CCL3 , Quimiocina CCL4 , Quimiocinas CC/genética , Proteínas de Ligação a DNA/genética , Feminino , Frequência do Gene , Marcadores Genéticos , Testes Genéticos/estatística & dados numéricos , Genótipo , Humanos , Hanseníase/etiologia , Proteínas Inflamatórias de Macrófagos , Masculino , Camundongos , Família Multigênica , Mutação Puntual , Proteínas/genética , Fator de Transcrição STAT5 , Transativadores/genética , Tuberculose/etiologia , Proteínas Supressoras de TumorRESUMO
EBNA-5 is one of the Epstein-Barr virus (EBV)-encoded nuclear proteins required for immortalization of human B lymphocytes. In the nuclei of EBV-transformed lymphoblastoid cell lines EBNA-5 is preferentially targetted to distinct nuclear foci. Previously we have shown (W.Q. Jiang, L. Szekely, V. Wendel-Hansen, N. Ringertz, G. Klein, and A. Rosen, Exp. Cell Res. 197:314-318, 1991) that the same foci also contained the retinoblastoma (Rb) protein. Using a similar double immunofluorescence technique, we now show that these foci colocalize with nuclear bodies positive for PML, the promyelocytic leukemia-associated protein. Artificial spreading of the chromatin by exposure to the forces of fluid surface tension disrupts this colocalization gradually, suggesting that the bodies consist of at least two subcomponents. Heat shock or metabolic stress induced by high cell density leads to the release of EBNA-5 from the PML-positive nuclear bodies and induces it to translocate to the nucleoli. In addition to their presence in nuclear bodies, both proteins are occasionally present in nuclear aggregates and doughnut-like structures in which PML is concentrated in an outer shell. Nuclear bodies with prominent PML staining are seen in resting B lymphocytes. This staining pattern does not change upon EBV infection. In freshly infected cells EBNA-5 antigens are first distributed throughout the nucleoplasm. After a few days intensely staining foci develop. These foci coincide with PML-positive nuclear bodies. At a later stage and in established lymphoblastoid cell lines EBNA-5 is almost exclusively present in the PML-positive nuclear foci. The colocalization is restricted to EBV-infected human lymphoblasts. The data presented indicate that the distinct EBNA-5 foci are not newly formed structures but the result of translocation of the viral protein to a specialized domain present already in the nuclei of uninfected cells.