title: Induction of apoptosis by c9, t11-CLA in human endometrial cancer RL 95-2 cells via ERα-mediated pathway.
abstract: Numerous studies have shown that conjugated linoleic acid (CLA) can inhibit cancer cells growth and induce apoptosis in vitro and in vivo. The aim of the present study was to investigate the effects of CLA, including cis9, trans11-conjugated linoleic acid (c9, t11-CLA) and trans10, cis12-conjugated linoleic acid (t10, c12-CLA), on apoptosis of human endometrial cancer RL 95-2 cells and its related mechanisms. The MTT analysis was used to evaluate the effect of CLA isomers on the viability of endometrial cancer RL 95-2 cells. We then estimated the apoptosis by Morphological observation and Annexin V-FITC/PI staining and flow cytometry. We also used Western blot analysis to assess the expression of caspase-3, Bax, Bcl-2 proteins and the activation of Akt/p-Akt and ERα/p-ERα. Propylpyrazole-triol (PPT), a selective ERα agonist was used to confirm the induction of apoptosis by c9, t11 CLA may relate to ERα-mediated pathway. In CLA-treated RL 95-2 cells, we found that c9, t11-CLA inhibited viability and trigged apoptosis, as judged from nuclear morphology and flow cytometric analysis. The expression of caspase-3 and the ratio of Bax/Bcl-2 were significant increased, but no obvious change was observed about Akt and p-Akt in c9, t11-CLA-treated cells. However, the expression of total ERα level in RL 95-2 cells-treated with c9, t11-CLA was unchanged, while in the concentration of 80 mM, c9, t11-CLA down-regulated the protein expression level of p-ERα. Then PPT has the antagonistic action on growth inhibitory effect in RL 95-2 cells incubated with c9, t11-CLA. This study demonstrated that c9, t11- CLA could induce apoptosis in RL 95-2 cells, and may involve in ERα-mediated pathway. These results indicated that c9, t11- CLA could induce apoptosis of endometrial cancer cells and may be potential agents for the treatment of endometrial cancer.
authors: Liaoning Key Laboratory of Food Biological Technology, School of Food Science and Technology, Dalian Polytechnic University, 116034 Dalian, China.
authors: Jihui
authors: J
authors: Wang
authors: Xiao
authors: X
authors: Liu
authors: Xiaojuan
authors: X
authors: Zhang
authors: Jing
authors: J
authors: Liu
authors: Shuhong
authors: S
authors: Ye
authors: Shan
authors: S
authors: Xiao
authors: Hongzhou
authors: H
authors: Chen
authors: Han
authors: H
authors: Wang
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D016889:Endometrial Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D004717:Endometrium / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D005260:Female; D006801:Humans; D044243:Linoleic Acids, Conjugated / Q000737:chemistry / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D044243:Linoleic Acids, Conjugated
keywords: Apoptosis; Conjugated linoleic acid; Endometrial cancer; Estrogen receptor