RESUMO
Gene expression profiling studies have reported up-regulated mRNA expression of the FOXP1 forkhead transcription factor in response to normal B-cell activation and high expression in a poor prognosis subtype of diffuse large B-cell lymphoma (DLBCL). The purpose of this study was to investigate the prognostic importance of FOXP1 protein expression in an independent series of DLBCL.First, the specificity of our FOXP1 monoclonal antibody was verified by confirming that it did not recognize the closely related FOXP2, FOXP3, or FOXP4 proteins. FOXP1 protein expression was then analyzed by immunohistochemistry using a DLBCL tissue microarray constructed from 101 previously untreated de novo cases from the British Columbia Cancer Agency. FOXP1 expression was scored as either positive (>30% positive nuclei) or negative (<30% positive nuclei). The overall survival curves clearly showed that patients grouped as FOXP1-positive (40%) had a significantly decreased overall survival (P = 0.0001). FOXP1-positive patients had a median overall survival of 1.6 years compared with 12.2 years in FOXP1-negative cases. In addition, FOXP1-positive patients showed a clear trend to earlier progression in comparison to the FOXP1-negative patients. The analysis of FOXP1 expression within low, medium, and high International Prognostic Index groupings found that FOXP1-negative patients had better overall survival within each group indicating that FOXP1 expression has predictive value independent of the International Prognostic Index subgrouping, a finding that was confirmed in multivariate analysis. These initial results suggest that FOXP1 expression may be important in DLBCL pathogenesis.
Assuntos
Linfoma de Células B/patologia , Linfoma Difuso de Grandes Células B/patologia , Proteínas Repressoras/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Especificidade de Anticorpos , Células COS , Chlorocebus aethiops , DNA Complementar/genética , Feminino , Fatores de Transcrição Forkhead , Humanos , Imuno-Histoquímica , Linfoma de Células B/genética , Linfoma de Células B/metabolismo , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Masculino , Pessoa de Meia-Idade , Plasmídeos/genética , Prognóstico , Proteínas Repressoras/genética , Proteínas Repressoras/imunologia , Análise de Sobrevida , Análise Serial de Tecidos , TransfecçãoRESUMO
Antibodies are widely exploited as research/diagnostic tools and therapeutics. Despite providing exciting research opportunities, the multitude of available antibodies also offers a bewildering array of choice. Importantly, not all companies comply with the highest standards, and thus many reagents fail basic validation tests. The responsibility for antibodies being fit for purpose rests, surprisingly, with their user. This paper condenses the extensive experience of the European Monoclonal Antibody Network to help researchers identify antibodies specific for their target antigen. A stepwise strategy is provided for prioritising antibodies and making informed decisions regarding further essential validation requirements. Web-based antibody validation guides provide practical approaches for testing antibody activity and specificity. We aim to enable researchers with little or no prior experience of antibody characterization to understand how to determine the suitability of their antibody for its intended purpose, enabling both time and cost effective generation of high quality antibody-based data fit for publication.