Deoxycholic Acid-Induced Signal Transduction in HT-29 Cells: Role of NF-kappa B and Interleukin-8.
- Author:
Dong Ki LEE
1
;
Sun Young PARK
;
Soon Koo BAIK
;
Sang Ok KWON
;
Jun Mo CHUNG
;
Eok Soo OH
;
Hyun Soo KIM
Author Information
1. Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea. hskim@wonju.yonsei.ac.kr
- Publication Type:Original Article ; English Abstract
- Keywords:
Deoxycholic acid;
HT-29 cells;
NF-kappa B;
Interleukin-8
- MeSH:
Blotting, Western;
Colonic Neoplasms;
Deoxycholic Acid/*pharmacology;
Dose-Response Relationship, Drug;
Electrophoretic Mobility Shift Assay;
English Abstract;
HT29 Cells;
Humans;
Interleukin-8/*metabolism;
NF-kappa B/*metabolism;
Oligonucleotides, Antisense/pharmacology;
Signal Transduction/*drug effects;
Taurochenodeoxycholic Acid/*pharmacology;
Trans-Activation (Genetics)/drug effects
- From:The Korean Journal of Gastroenterology
2004;43(3):176-185
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND/AIMS: Deoxycholic acid (DCA) has been appeared to be an endogenous colon tumor promoter. In this study, we investigated whether DCA induces nuclear factor-kappa B (NF-kappa B) activation and IL-8 expression, and tauroursodeoxycholic acid (TUDC) inhibits this signaling in HT-29 cells. METHODS: After DCA treatments, time courses of NF-kappa B binding activity were determined by electrophoretic mobility shift assay (EMSA). Also, we performed Western blotting of I kappa B alpha to confirm NF-kappa B activation. Time and concentration courses of DCA-induced secretion of IL-8 were measured with ELISA in supernatants of cultured media from the cells. To evaluate the role of NF-kappa B, IL-8 levels were assessed after pretreatment with using phosphorothioate-modified anti-sense oligonucleotides (ODN). Moreover, DCA-induced secretions of IL-8 were measured after pretreatment with TUDC. RESULTS: DCA dose-dependently induced prominent NF-kappa B binding complexes from 30 min to 8 hr and degradation of I kappa B alpha. The secretions of IL-8 were increased with DCA (50~200 micro M) treatment in a time and dose-dependent manner. Pre-incubation of the cells with TUDC (0.1~10 micro M) for 2 hours caused significant decreases in DCA induced IL-8 secretion. However, transient transfection using p50 or p65 AS-ODN showed no effect on IL-8 secretion. CONCLUSIONS: DCA may play as a colonic tumor promoter through anti-apoptotic effect of NF-kappa B activation and IL-8 expression, and DCA-induced NF-kappa B independent IL-8 expression is inhibited by TUDC.
