title: Immunohistochemistry of apoptosis-related proteins in retinoblastoma.
abstract: Retinoblastoma is the most common intraocular malignant neoplasia during childhood and results from the partial or total inactivity of the retinoblastoma protein (pRb). In the absence of pRb, the E2F transcription factors increase the levels of cell cycle proteins as well as some pro-apoptotic proteins. We intended to study the immunohistochemistry profile of apoptotic-related proteins in retinoblastoma. We also evaluated the association between the expression of apoptotic protein and stage of tumor or survivor after a 5year follow up. Apoptosis-related proteins (Apaf-1, Bak, Bax, Bcl-2, Bcl-xL, Bim-long, MDM2, p53, pro-caspase-3, PUMA, Smac/DIABLO and cleaved caspase-3) were evaluated using immunohistochemistry on tissue microarrays which contained samples of retinoblastoma tumors taken from ninety-three patients without any treatment previous to surgery. The immunohistochemistry reactions were evaluated using an optical microscope as well as the ACIS III®platform. The pro-apoptotic proteins (APAF-1, Bax, p53, PUMA, Smac/DIABLO) were more frequently expressed than the anti-apoptotic proteins (Bcl-2, Bcl-xL and MDM2). The protein Bcl-xL had a negative correlation with cleaved caspase-3, a marker of cell apoptosis. Bcl-xL may be implicated in an apoptosis block.
authors.affiliation: Department of Pathology, A.C. Camargo Cancer Center, Sao Paulo, Brazil. Electronic address: renato.natalino@hc.fm.usp.br.
authors.forename: Renato José Mendonça
authors.initials: RJ
authors.lastname: Natalino
authors.affiliation: Department of Oncology, Universidade Santo Amaro, Sao Paulo, Brazil.
authors.forename: Célia Beatriz Gianotti
authors.initials: CB
authors.lastname: Antoneli
authors.affiliation: Department of Social Medicine, Faculdade de Ciências Médicas da Santa Casa de São Paulo, Sao Paulo, Brazil.
authors.forename: Karina de Cássia Braga
authors.initials: KC
authors.lastname: Ribeiro
authors.affiliation: Department of Pathology, A.C. Camargo Cancer Center, Sao Paulo, Brazil.
authors.forename: Antônio Hugo José Fróes Marques
authors.initials: AH
authors.lastname: Campos
authors.affiliation: Department of Pathology, A.C. Camargo Cancer Center, Sao Paulo, Brazil.
authors.forename: Fernando Augusto
authors.initials: FA
authors.lastname: Soares
mesh_terms: D017209:Apoptosis / Q000502:physiology; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D008297:Male; D019572:Retinal Neoplasms / Q000378:metabolism* / Q000473:pathology; D012175:Retinoblastoma / Q000378:metabolism* / Q000473:pathology
chemical_list: D051017:Apoptosis Regulatory Proteins
keywords: Apoptosis; Retinoblastoma; bcl-X protein