Induction of major histocompatibility complex class I molecules on human neuroblastoma line cells by a flavoid antioxidant

Human major histocompatibility complex (MHC) class I expression is usually suppressed in neuronal cells and neuroblastoma cells. in the present study, we analyzed the effect of a flavonoid antioxidant silymarin, on the induct ion of MHC class I molecules in human neuroblastoma line cells. Treatment o f neuroblastoma cells with silymarin resulted in the expression of MHC clas s I molecules. Silymarin treatment enhanced the transcriptional activity of the reporter construct containing MHC class I promoter truncated within -4 28 bp of transcription initiation, but not the construct containing the p r emoter truncated with in -284 bp, Because an E-box element is located betwe en -428 a nd -285 bp of the transcription initiation, results suggest that silymarin acts on the enhancer activity of the E-box in the MHC class I pro moter. Our findings indicate that silymarin induces the transcriptional fac tors to enhance the MHC class I promoter through the class I E-box element. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.