Studies on PPAR gamma Signal Pathway of Conjugated Linoleic Acid Isomers Induce Apoptosis of Human Breast Cancer Cell Line SKBr3

Cis9, trans 11 and trans 10, cis 12-CLA are two major isomers of conjugated linoleic acid, which have stronger activities of anti-tumor. Based the previous studies, it was explored the pathway and mechanism of inducing apoptosis in human breast cancer cell line SKBR3 by c9, t11-CLA and t10, c 12-CLA. It was confirmed that CLA could increase obviously the transcription and protein expression levels of PPAR gamma by RT-PCR and Western blot. The synchronism and correlation between PPAR gamma and apoptotic proteins Bax, Bcl-2, caspase3 changes were found with a dose- and time-dependent manner. PPAR gamma inhibitor GW9662 experimental result showed that there is cooperative relation between them. This is the first report that CLA induces apoptosis in SKBr3 cell by the signal pathway of PPAR gamma-Bcl-2-Caspase3. These observations indicated that CLA will be useful for clinic therapy of anti-tumor as a new regulator of PPAR gamma in the future.