Transcriptional regulation of the human Sia-alpha2,3-Gal-beta1,4-GlcNAc-R:alpha2,8-sialyltransferase (hST8Sia III) by retinoic acid in human glioblastoma tumor cell line.
In this study, we have shown the transcriptional regulation of the human Sia-alpha2,3-Gal-beta1,4-GlcNAc-R:alpha2,8-sialyltransferase (hST8Sia III) induced by retinoic acid (RA), a potent neuronal cell regulator in glioblastoma cell line (U-87MG). The induction of hST8Sia III by RA is regulated at the transcriptional level in a dose- and time-dependent manner, as evidenced by reverse transcription-polymerase chain reaction (RT-PCR). To elucidate the mechanism underlying the regulation of hST8Sia III gene expression in RA-stimulated U-87MG cells, we characterized the promoter region of the hST8Sia III gene. Functional analysis of the 5'-flanking region of the hST8Sia III gene by the transient expression method showed that the -1194 to -816 region, which contains a retinoic acid nucleic receptor (RAR) at -1000 to -982, functions as the RA-inducible promoter in U-87MG cells. Site-directed mutagenesis indicated that the RA binding site at -996 to -991 is crucial for the RA-induced expression of the hST8Sia III in U-87MG cells. In addition, the transcriptional activity of hST8Sia III induced by RA in U-87MG cells was strongly inhibited by SP600125, c-Jun N-terminal Kinase (JNK) inhibitor, as determined by RT-PCR and luciferase assay of hST8Sia III promoter containing the -1194 to -816 regions. These results suggest that RA markedly modulates transcriptional regulation of hST8Sia III gene expression through JNK signal pathway in U-87MG cells.
Kim
Seok-Jo
SJ
Department of Biotechnology, Dong-A University, Busan 604-714, Korea.
Choi
Hee-Jung
HJ
Jin
Un-Ho
UH
Lee
Young-Choon
YC
Kim
Cheorl-Ho
CH
D001483:Base Sequence; D001932:Brain Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D004247:DNA; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D005909:Glioblastoma / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012799:Sialyltransferases / Q000235:genetics*; D015533:Transcriptional Activation / Q000187:drug effects*; D014212:Tretinoin / Q000494:pharmacology*
D014212:Tretinoin; D004247:DNA; C094133:Sia(alpha2,3)Gal(beta1,4)GlcNAc alpha-2,8-sialyltransferase; D012799:Sialyltransferases