Triptolide downregulates human GD3 synthase (hST8Sia I) gene expression in SK-MEL-2 human melanoma cells.
In this study, we have shown that gene expression of human GD3 synthase (hST8Sia I) is suppressed by triptolide (TPL) in human melanoma SK-MEL-2 cells. To elucidate the mechanism underlying the downregulation of hST8Sia I gene expression in TPL-treated SK-MEL-2 cells, we characterized the TPL-inducible promoter region within the hST8Sia I gene using luciferase constructs carrying 5'-deletions of the hST8Sia I promoter. Functional analysis of the 5'-flanking region of the hST8Sia I gene demonstrated that the -1146 to -646 region, which contains putative binding sites for transcription factors c-Ets-1, CREB, AP-1 and NF-κB, functions as the TPL-inducible promoter of hST8Sia I in SK-MEL-2 cells. Site-directed mutagenesis and ChIP analysis indicated that the NF-κB binding site at -731 to -722 is crucial for TPL-induced suppression of hST8Sia I in SK-MEL-2 cells. This suggests that TPL induces down-regulation of hST8Sia I gene expression through NF-κB activation in human melanoma cells.
Department of Biotechnology, Brain Korea 21 Center for Silver-Bio Industrialization, Dong-A University, Busan 604-714, Korea.
Haw-Young
HY
Kwon
Seok-Jo
SJ
Kim
Cheorl-Ho
CH
Kim
Sung-Wook
SW
Son
Kyoung-Sook
KS
Kim
Jai-Heon
JH
Lee
Su-Il
SI
Do
Young-Choon
YC
Lee
D049109:Cell Proliferation / Q000187:drug effects; D004224:Diterpenes / Q000494:pharmacology*; D015536:Down-Regulation; D004852:Epoxy Compounds / Q000494:pharmacology; D017930:Genes, Reporter; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism; D010616:Phenanthrenes / Q000494:pharmacology*; D011401:Promoter Regions, Genetic; D012799:Sialyltransferases / Q000096:biosynthesis* / Q000235:genetics; D014407:Tumor Cells, Cultured
D004224:Diterpenes; D004852:Epoxy Compounds; D016328:NF-kappa B; D010616:Phenanthrenes; C001899:triptolide; D012799:Sialyltransferases; C043662:alpha-N-acetylneuraminate alpha-2,8-sialyltransferase