Imunoexpressão das tetraspaninas (CD9 E UPIII) no carcinoma urotelial de bexiga / Immunoexpression of tetraspanin (CD9 e UPIII) in bladder urothelial carcinoma

Introdução: O carcinoma urotelial da bexiga é uma doença de alta incidência e letalidade. Recentemente, tem sido caracterizado em subtipos moleculares, com diferenças prognósticas e de resposta terapêutica. As tetraspaninas estão implicadas na adesão celular e sinalização intercelular, interferindo diretamente em fenômenos como a morfogênese dos tecidos e migração. Uma vez que os subtipos moleculares luminal e basal correspondem, respectivamente, a fenótipos celulares urotelial bem diferenciado e de reserva basal, é possível que a expressão das tetraspaninas acompanhe esse racional, o que traria possibilidade de integração no cenário clínico. Metodologia: Amostras de 88 pacientes operados (cistectomia radical) por carcinoma urotelial, preservadas em parafina, foram organizadas em TMA ou cortes inteiros, submetidos a imuno-histoquímica. As reações foram analisadas por microscopia ótica convencional e acessadas quanto à intensidade de expressão - negativo, fraco e forte (escore subjetivo) e extensão de expressão ­ negativo, focal e difuso (baseado na porcentagem das células positivas, em cortes de 1-50%; >50%). Os tumores foram classificados em Luminal, Basal e Sem tipo definido, a partir da expressão imuno-histoquímica de GATA3, CK5/6 e CK14. A expressão citoplasmática das tetraspaninas (CD9 e UPIII) foi avaliada em tecidos tumoral e urotelial não neoplásico pareado, e correlacionadas com parâmetros patológicos e clínicos. Resultados: A idade média foi de 66.9 anos, com relação H:M de 2:1 e 72% de tabagistas ou ex-tabagistas. A maior parte (62%) das cirúrgicas foram indicadas por doença músculo-invasiva já ao diagnóstico e o restante por doença não músculo-invasiva extensa/recorrente ou progredida para carcinoma músculo invasor, sendo o estadiamento final na cistectomia 14%

Introduction: Urothelial carcinoma of the bladder is a disease with high incidences and letality. It has recently been carachterized in molecular subtypes, with differences regarding prognosis and response to treatment. Tetraspanins are implicated in cell adhesion and intercellular signaling, directly interfering in phenomena such as tissue morphogenesis and migration. Considering that luminal and basal molecular subtypes correspond, repectively, to well differentiated urotelial and basal reserve cell phenotypes, it is possible that tetraspanin expression may follow this rationale, which could bare potential to integration into the clinical scenario. Methodology: Paraffin-preserved samples from 88 patients submitted to radical cystectomy for urothelial carcinoma were organized into TMAs or whole sections, labeled with immunohistochemistry. Reactions were analyzed by conventional optical microscopy and accessed as to expression intensity ­ negative, weak or strong (subjective scoring) and extent ­ negative, focal or diffuse (based on percentage of positive cells in cut-offs of 1-50%; >50%). Tumors were classified into Luminal, Basal and Non-type based on immunoexpression of GATA3, CK14 and CK5/6. Cytoplasmic expression of tetraspanins was evaluated in neoplastic and non-neoplastic urotelial tissue and correlated with clinical and morphological parameters. Results: Mean age was 66.9 years, with M:F ratio of 2:1 and 72% smokers or ex-smokers. The majority (62%) of surgeries was indicated because of muscle-invasive disease at presentation and the rest for extensive/recurrent non muscle-invasive disease or progression to invasive carcinoma (final pathological stage at cystectomy: 14%

Exosomes: mediators of communication in eukaryotes

In addition to the established mechanisms of intercellular signaling, a new way of communication has gained much attention in the last decade: communication mediated by exosomes. Exosomes are nanovesicles (with a diameter of 40-120 nm) secreted into the extracellular space by the multivesicular endosome after its outer membrane fuses with the plasma membrane. Once released, exosomes modulate the response of the recipient cells that recognize them. This indicates that exosomes operate in a specific manner and participate in the regulation of the target cell. Remarkably, exosomes occur from unicellular organisms to mammals, suggesting an evolutionarily conserved mechanism of communication. In this review we describe the cascade of exosome formation, intracellular traffic, secretion, and internalization by recipient cells, and review their most relevant effects. We also highlight important steps that are still poorly understood.