RESUMO
Epstein-Barr virus (EBV) genome-chips are employed to determine the EBV infection rate and to reveal the gene expression patterns of EBV in tumor biopsies. These chips are produced with 71 consecutive PCR-amplified EBV DNA fragments of 1-3 kbp covering the entire EBV genome. The specificity of the EBV-chips is determined by hybridizing the DNA on the chips with biotin-labeled cDNA probes reverse transcribed from the mRNA of P3HR1 cells, which were B-cell infected latently by EBV. Hybridization results revealed only the expression of EBNA1, EBNA2, EBER1 and EBER2 in these cells. On the other hand, EBV lytic genes are expressed after the cells are treated with 12-O-tetradecanoylphorbol-13-acetate and sodium butyrate to induce the EBV lytic cycle. Fourty-four tumor biopsies from different organs are assayed with these chips, which showed many defined and interesting EBV gene expression patterns. This study demonstrates that the EBV-chip is useful for screening infection with EBV in tumors, which may lead to insights into tumorigenesis associated with this virus.
Assuntos
Infecções por Vírus Epstein-Barr/virologia , Regulação Neoplásica da Expressão Gênica , Regulação Viral da Expressão Gênica , Herpesvirus Humano 4/genética , Análise em Microsséries/métodos , Neoplasias/virologia , Linfócitos B/citologia , Linfócitos B/efeitos dos fármacos , Linfócitos B/virologia , Linfoma de Burkitt/patologia , Butiratos/farmacologia , Linhagem Celular Tumoral , DNA Viral/genética , Estudos de Avaliação como Assunto , Perfilação da Expressão Gênica , Genes Virais , Genoma Viral , Humanos , RNA Mensageiro/metabolismo , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
(-)-Epigallocatechin gallate (EGCG), abundant in green tea, is a potent anti-microbial and anti-tumor compound. This investigation used immunoblot, flow cytometry, microarray, and indirect immunofluorescence analyses to show that at concentrations exceeding 50 microM, EGCG inhibits the expression of Epstein-Barr virus (EBV) lytic proteins, including Rta, Zta, and EA-D, but does not affect the expression of EBNA-1. Moreover, DNA microarray and transient transfection analyses demonstrated that EGCG blocks EBV lytic cycle by inhibiting the transcription of immediate-early genes, thus inhibiting the initiation of EBV lytic cascade.
