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Titolo:
Mechanisms of inhibition of the Ras-MAP kinase signaling pathway in 30.7b Ras 12 cells by tea polyphenols (-)-epigallocatechin-3-gallate and theaflavin-3,3 '-digallate
Autore:
Chung, JY; Park, JO; Phyu, H; Dong, ZG; Yang, CS;
Indirizzi:
Rutgers State Univ, Coll Pharm, Canc Res Lab, Piscataway, NJ 08854 USA Rutgers State Univ Piscataway NJ USA 08854 Lab, Piscataway, NJ 08854 USA Univ Minnesota, Hormel Inst, Austin, MN 55912 USA Univ Minnesota Austin MN USA 55912 ota, Hormel Inst, Austin, MN 55912 USA
Titolo Testata:
FASEB JOURNAL
fascicolo: 9, volume: 15, anno: 2001,
pagine: NIL_191 - NIL_208
SICI:
0892-6638(200107)15:9<NIL_191:MOIOTR>2.0.ZU;2-2
Fonte:
ISI
Lingua:
ENG
Soggetto:
ACTIVATOR PROTEIN-1 ACTIVITY; NITRIC-OXIDE SYNTHASE; PROLINE-RICH PROTEINS; INDUCED AP-1 ACTIVITY; STOMACH-CANCER CELLS; FACTOR-KAPPA-B; BLACK TEA; GREEN TEA; LUNG TUMORIGENESIS; A/J MICE;
Keywords:
tea polyphenols; MAP kinases; Erk1/2 activity; MEK1/2; Raf-1;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
56
Recensione:
Indirizzi per estratti:
Indirizzo: Yang, CS Rutgers State Univ, Coll Pharm, Canc Res Lab, 164 Frelinghuysen Rd, Piscataway, NJ 08854 USA Rutgers State Univ 164 Frelinghuysen Rd Piscataway NJ USA 08854 A
Citazione:
J.Y. Chung et al., "Mechanisms of inhibition of the Ras-MAP kinase signaling pathway in 30.7b Ras 12 cells by tea polyphenols (-)-epigallocatechin-3-gallate and theaflavin-3,3 '-digallate", FASEB J, 15(9), 2001, pp. NIL_191-NIL_208

Abstract

Our previous study showed that tea polyphenols inhibited MAP kinase and AP-1 activities in mouse epidermal JB6 cells and the corresponding H-ras-transformed cell line 30.7b Ras 12. The present study investigated the mechanisms of this inhibition. The cells were incubated with (-)-epigallocatechin-3-gallate (EGCG) or theaflavin-3,3'-digallate (TFdiG) (20 muM) for differenttimes, and the cell lysate was analyzed by immunoblotting. EGCG treatment decreased the levels of phospho-Erk1/2 and -MEK1/2 time-dependently (by 60%at 60 min). TFdiG lowered their levels by 38%-50% at 15 min. TFdiG effectively decreased total Raf-1 protein levels, most likely through lysosomal degradation. EGCG did not affect protein levels or the activity of Raf-1 significantly but decreased its association with MEK1 as determined by co-immunoprecipitation. In addition, EGCG and TFdiG (10 muM) inhibited the phosphorylation of Elk-1 by isolated phospho-Erk1/2 in vitro. This inhibition of Erk1/2 activity is Elk-1 concentration-dependent and ATP concentration-independent, which suggests that EGCG and TFdiG interfere with the binding of theprotein substrate to the kinase. The presently demonstrated specific mechanisms of inhibition of MAP kinases by EGCG and TFdiG may help us to understand the effects of tea consumption on cancer, inflammatory diseases, and cardiovascular diseases.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 19/01/20 alle ore 14:31:46