RESUMO
Lymphomas are classified according to the World Health Organisation (WHO) classification which defines subtypes on the basis of clinical, morphological, immunophenotypic, molecular and cytogenetic criteria. Differential diagnosis of the subtypes is sometimes difficult, especially for small B-cell lymphoma (SBCL). Standardisation of molecular genetic assays using multiple gene expression analysis by microarrays could be a useful complement to the current diagnosis. The aim of the present study was to develop a low density DNA microarray for the analysis of 107 genes associated with B-cell non-Hodgkin lymphoma and to evaluate its performance in the diagnosis of SBCL. A predictive tool based on Fisher discriminant analysis using a training set of 40 patients including four different subtypes (follicular lymphoma n = 15, mantle cell lymphoma n = 7, B-cell chronic lymphocytic leukemia n = 6 and splenic marginal zone lymphoma n = 12) was designed. A short additional preliminary analysis to gauge the accuracy of this signature was then performed on an external set of nine patients. Using this model, eight of nine of those samples were classified successfully. This pilot study demonstrates that such a microarray tool may be a promising diagnostic approach for small B-cell non-Hodgkin lymphoma.
Assuntos
Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Linfoma de Células B/diagnóstico , Análise de Sequência com Séries de Oligonucleotídeos , Inteligência Artificial , Diagnóstico Diferencial , Humanos , Leucemia Linfocítica Crônica de Células B/diagnóstico , Leucemia Linfocítica Crônica de Células B/genética , Linfoma de Células B/classificação , Linfoma de Células B/genética , Linfoma de Zona Marginal Tipo Células B/diagnóstico , Linfoma de Zona Marginal Tipo Células B/genética , Linfoma Folicular/diagnóstico , Linfoma Folicular/genética , Linfoma de Célula do Manto/diagnóstico , Linfoma de Célula do Manto/genética , Projetos Piloto , RNA Neoplásico/análise , RNA Neoplásico/isolamento & purificaçãoRESUMO
Different mechanisms of drug resistance, including ATP-binding cassette (ABC) transporters, are responsible for treatment failure of tumors. We developed a low-density DNA microarray which contains 38 genes of the ABC transporter gene family. This tool has been validated with three different multidrug-resistant sublines (CEM/ADR5000, HL60/AR, and MCF7/CH1000) known to overexpress either the ABCB1 (MDR1), ABCC1 (MRP1), or ABCG2 (MXR and BCRP) genes. When compared with their drug-sensitive parental lines, we observed not only the overexpression of these genes in the multidrug-resistant cell lines but also of other ABC transporter genes pointing to their possible role in multidrug resistance. These results were corroborated by quantitative real-time reverse transcription-PCR. As the microarray allows the determination of the expression profile of many ABC transporters in a single hybridization experiment, it may be useful as a diagnostic tool to detect drug resistance in clinical samples.
