TY - JOUR
T1 - The specific anti-cancer activity of green tea (-)-epigallocatechin-3-gallate (EGCG)
AU - Wang, Y. C.
AU - Bachrach, U.
PY - 2002
Y1 - 2002
N2 - The effect of the green tea polyphenol-(-)epigallocatechin-3-gallate (EGCG) was tested in cultures of normal and transformed NIH-pATMras fibroblasts. In this system transformation can be induced at will by the addition of dexamethasone, which induces the expression of H-ras by activating the mammary tumor virus long terminal repeat (MMTV-LTR) promoter. This facilitates a reliable comparison of the susceptibility of normal and transformed cells to EGCG. It has been shown that EGCG inhibited the growth of transformed but not of the normal fibroblasts. In an attempt to elucidate the mode of the preferential inhibitory activity of EGCG, its effect on growth promoting factors has been examined. The level of ornithine decarboxylase (ODC, EC 4.1.1.17), which is a signal for cellular proliferation, was reduced by EGCG in the transformed but not in the normal cells. EGCG also showed strong inhibition of tyrosine kinase and mitogen-activated protein kinase (MAPK) activities, without affecting the kinases in the normal cells. Similarly, EGCG also preferentially decreased the levels of the oncogenes Ras and Jun in transformed cell. EGCG preferentially induced apoptosis in the transformed fibroblasts. In vitro chemosen-sitivity tests demonstrated that EGCG inhibited the proliferation of leukemic cells. These findings suggest that EGCG has a therapeutic potential in the combat against cancer.
AB - The effect of the green tea polyphenol-(-)epigallocatechin-3-gallate (EGCG) was tested in cultures of normal and transformed NIH-pATMras fibroblasts. In this system transformation can be induced at will by the addition of dexamethasone, which induces the expression of H-ras by activating the mammary tumor virus long terminal repeat (MMTV-LTR) promoter. This facilitates a reliable comparison of the susceptibility of normal and transformed cells to EGCG. It has been shown that EGCG inhibited the growth of transformed but not of the normal fibroblasts. In an attempt to elucidate the mode of the preferential inhibitory activity of EGCG, its effect on growth promoting factors has been examined. The level of ornithine decarboxylase (ODC, EC 4.1.1.17), which is a signal for cellular proliferation, was reduced by EGCG in the transformed but not in the normal cells. EGCG also showed strong inhibition of tyrosine kinase and mitogen-activated protein kinase (MAPK) activities, without affecting the kinases in the normal cells. Similarly, EGCG also preferentially decreased the levels of the oncogenes Ras and Jun in transformed cell. EGCG preferentially induced apoptosis in the transformed fibroblasts. In vitro chemosen-sitivity tests demonstrated that EGCG inhibited the proliferation of leukemic cells. These findings suggest that EGCG has a therapeutic potential in the combat against cancer.
KW - (-)-Epigallocatechin-3-gallate (EGCG)
KW - Amino acids
KW - Apoptosis
KW - Mitogen-activated protein kinase (MAPK)
KW - Oncogene
KW - Ornithine decarboxylase (ODC)
KW - Tyrosine kinase
UR - http://www.scopus.com/inward/record.url?scp=0036205282&partnerID=8YFLogxK
U2 - 10.1007/s007260200002
DO - 10.1007/s007260200002
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C2 - 12395181
AN - SCOPUS:0036205282
SN - 0939-4451
VL - 22
SP - 131
EP - 143
JO - Amino Acids
JF - Amino Acids
IS - 2
ER -