TY - JOUR
T1 - The gene regulating activity of thyroid hormone nuclear receptors is modulated by cell-type specific factors
AU - Lin, Kwang huei
AU - Chen, Shen liang
AU - Zhu, Xu Guang
AU - Shieh, Hsing ying
AU - McPhie, Peter
AU - Cheng, Sheue yann
PY - 1997/9/18
Y1 - 1997/9/18
N2 - To understand whether the transcriptional activity of thyroid hormone nuclear receptors (TRs) is modulated by cell-type specific factors, full length TR subtype α1 (TRα1) and β1 (TRβ1) cDNAs were cloned from human hepatoma cell lines: HA22T, SK-Hep-1 and HepG2. The cloned receptor bound to the thyroid hormone 3,3',5-triiodo-L-thyronine (T3) and the thyroid hormone response elements (TREs) similarly to those cloned from other tissues. They exhibited T3- and TRE-dependent transactivation activities, indicating these TRs were transcriptionally active. The lipogenic malic enzyme (ME), a T3-target gene in liver, was stimulated ~ 3- and 1.5-fold by T3 in HA22T and SK-Hep-1, respectively. The T3-stimulated ME gene expression was inhibited in HA22T, but stimulated in SK-Hep-1 cells by insulin. These results suggest that the gene regulating activity of TRs was modulated by cell-type specific factors. Furthermore, these cell-type specific factors could modulate the cross talk between TR- and insulin receptor-mediated pathways.
AB - To understand whether the transcriptional activity of thyroid hormone nuclear receptors (TRs) is modulated by cell-type specific factors, full length TR subtype α1 (TRα1) and β1 (TRβ1) cDNAs were cloned from human hepatoma cell lines: HA22T, SK-Hep-1 and HepG2. The cloned receptor bound to the thyroid hormone 3,3',5-triiodo-L-thyronine (T3) and the thyroid hormone response elements (TREs) similarly to those cloned from other tissues. They exhibited T3- and TRE-dependent transactivation activities, indicating these TRs were transcriptionally active. The lipogenic malic enzyme (ME), a T3-target gene in liver, was stimulated ~ 3- and 1.5-fold by T3 in HA22T and SK-Hep-1, respectively. The T3-stimulated ME gene expression was inhibited in HA22T, but stimulated in SK-Hep-1 cells by insulin. These results suggest that the gene regulating activity of TRs was modulated by cell-type specific factors. Furthermore, these cell-type specific factors could modulate the cross talk between TR- and insulin receptor-mediated pathways.
UR - http://www.scopus.com/inward/record.url?scp=0031577529&partnerID=8YFLogxK
U2 - 10.1006/bbrc.1997.7285
DO - 10.1006/bbrc.1997.7285
M3 - 期刊論文
C2 - 9299494
AN - SCOPUS:0031577529
SN - 0006-291X
VL - 238
SP - 280
EP - 284
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 2
ER -