RT Journal Article
SR Electronic
T1 Conjugated Linoleic Acid (CLA) Up-regulates the Estrogen-regulated Cancer Suppressor Gene, Protein Tyrosine Phosphatase γ (PTPγ), in Human Breast Cells
JF Anticancer Research
JO Anticancer Res
FD International Institute of Anticancer Research
SP 27
OP 34
VO 26
IS 1A
A1 WANG, LI-SHU
A1 HUANG, YI-WEN
A1 SUGIMOTO, YASURO
A1 LIU, SULING
A1 CHANG, HSIANG-LIN
A1 YE, WEIPING
A1 SHU, SHERRY
A1 LIN, YOUNG C.
YR 2006
UL http://ar.iiarjournals.org/content/26/1A/27.abstract
AB Background: Conjugated linoleic acid (CLA), a naturally occurring compound found in ruminants products, has been shown to possess anticancer properties in vivo and in vitro. There are several CLA isomers in ruminant-produced foods, among which t10,c12-CLA and c9,t11-CLA are the most potent. Protein tyrosine phosphatase γ (PTPγ) has been implicated as a tumor suppressor gene in kidney and lung cancers. Our previous results indicated that estradiol-17β (E2)-induced suppression of PTPγ may play a role in mammary tumorigenesis. Materials and Methods: The effects of t10,c12-CLA and c9,t11-CLA on PTPγ mRNA expression in human breast epithelial cells and stromal cells, isolated from surgical specimens of mammoplasty and breast cancer patients, were detected and quantified by RT-PCR. Results: The PTPγ mRNA expression was lower in cancer than in normal breast cells. Both t10,c12-CLA and c9,t11-CLA significantly (p<0.05) increased the PTPγ mRNA levels in primary cultured normal breast epithelial cells, normal breast stromal cells and breast cancer epithelial cells, but not in breast cancer stromal cells. t10,c12-CLA appeared to be the most active isomer in estrogen receptor α(ERα)-positive human breast cancer epithelial cells. Conclusion: The results indicate that dietary CLA might serve as a chemo-preventive and chemo-therapeutic agent in human breast cancers by up-regulating the estrogen-regulated tumor suppressor gene, PTPγ expression. Copyright© 2006 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved