Cell-type specific regulation of thrombospondin-1 expression and its promoter activity by regulatory agents.
- Author:
Soo A KIM
1
;
Jong Hoon KANG
;
In Ho CHO
;
Sung Won BAE
;
Kyong Ja HONG
Author Information
1. Department of Biochemistry, College of Medicine, the Catholic University of Korea, Seoul.
- Publication Type:Original Article
- Keywords:
All-trans retinoic acid;
IFN-g;
IL-6;
PMA;
TSP-1;
Hep3B;
PAE cell
- MeSH:
Animal;
Cell Line;
Endothelium, Vascular/cytology/drug effects/metabolism;
*Gene Expression Regulation/drug effects;
Genes, Reporter;
Genes, jun;
Human;
Immunoblotting;
Interferon Type II/pharmacology;
Interleukin-6/pharmacology;
*Promoter Regions (Genetics);
Proto-Oncogene Proteins c-jun/genetics/metabolism;
Receptors, Retinoic Acid/genetics/metabolism;
Recombinant Fusion Proteins/metabolism;
Tetradecanoylphorbol Acetate/pharmacology;
Thrombospondin 1/*genetics/metabolism;
Transcription, Genetic;
Tretinoin/pharmacology
- From:Experimental & Molecular Medicine
2001;33(3):117-123
- CountryRepublic of Korea
- Language:English
-
Abstract:
Thrombospondin-1 (TSP-1), a multifunctional protein that is able to function as a negative regulator of solid tumor progression and angiogenesis, is normally present at a very low level but rapidly elevated in pathological tissues. To understand the cellular regulation of TSP-1 expression, the mode of it's expression in Hep3B, SK-HEP-1, and porcine aortic endothelial (PAE) cells was examined in the presence of all-trans retinoic acid (ATRA), interleukin-6 (IL-6), interferon-gamma (IFN-gamma), or phorbol 12-myristate 13-acetate (PMA). ATRA or IL-6 induced a dose-dependent increase of TSP-1 protein and mRNA levels in PAE cells, while they negatively regulated TSP-1 expression in the Hep3B and SK-HEP-1 cells. In contrast, PMA showed just the opposite effects on the TSP-1 expression in the same cells. IFN-gamma had little effect on TSP-1 level in Hep3B and PAE cells. The TSP-1 expression in SK-HEP-1 cells by these agents showed a close resemblance to that of liver cells rather than that of the endothelial cell line. Possible TSP-1 promoter-mediated responses by ATRA, IL-6, IFN-gamma, or PMA in Hep3B and PAE cells examined with luciferase activity of TSP-LUC reporter plasmid showed that levels of TSP-1 promoter activity were lower than that of the expressed TSP-1 protein and mRNA levels. Transfection of c-Jun and/or RARalpha expression vectors into Hep3B and PAE cells resulted in the enhanced TSP-1 promoter activity as well as the increments of of its protein and mRNA level. These results suggest that regulatory agents-induced TSP-1 expression may be attributed to mRNA stability and/or translational activation in concert with transcriptional activation and TSP-1 expression may be independently controlled via each signal pathway stimulated by PMA or ATRA.
