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 induction of MHC class I molecules in human neuroblastoma line cells. Treatment of neuroblastoma cells with silymarin resulted in the expression of MHC class I molecules. Silymarin treatment enhanced the transcriptional activity of the reporter construct containing MHC class I promoter truncated within -428 bp of transcription initiation, but not the construct containing the promoter truncated within -284 bp. Because an E-box element is located between -428 and -285 bp of the transcription initiation, results suggest that silymarin acts on the enhancer activity of the E-box in the MHC class I promoter. Our findings indicate that silymarin induces the transcriptional factors to enhance the MHC class I promoter through the class I E-box element.
Sakai
K
K
Department of Neurology, Kanazawa Medical University, 1-1 Daigaku, Uchinada-machi, Kahoku-gun, 920-0293 Ishikawa, Japan. ksakai@kanazawa-med.ac.jp
Li
Y
Y
Shirakawa
T
T
Kitagawa
Y
Y
Hirose
G
G
D000975:Antioxidants / Q000494:pharmacology*; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects / Q000276:immunology; D017930:Genes, Reporter; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D009447:Neuroblastoma; D009474:Neurons / Q000166:cytology / Q000502:physiology; D012838:Silymarin / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects / Q000276:immunology; D014407:Tumor Cells, Cultured
D000975:Antioxidants; D015395:Histocompatibility Antigens Class I; D012838:Silymarin