Activation of peroxisome proliferator-activated receptor-?/? (PPAR-?/?) inhibits human breast cancer cell line tumorigenicity.

ABSTRACT: The effect of activation and overexpression of the nuclear receptor PPAR-?/? in human MDA-MB-231 (estrogen receptor-negative; ER(-)) and MCF7 (estrogen-receptor-positive; ER(+)) breast cancer cell lines was examined. Target gene induction by ligand activation of PPAR-?/? was increased by overexpression of PPAR-?/? compared with controls. Overexpression of PPAR-?/? caused a decrease in cell proliferation in MCF7 and MDA-MB-231 cells compared with controls, whereas ligand activation of PPAR-?/? further inhibited proliferation of MCF7 but not MDA-MB-231 cells. Overexpression and/or ligand activation of PPAR-?/? in MDA-MB-231 or MCF7 cells had no effect on experimental apoptosis. Decreased clonogenicity was observed in both MDA-MB-231 and MCF7 overexpressing PPAR-?/? in response to ligand activation of PPAR-?/? as compared with controls. Ectopic xenografts developed from MDA-MB-231 and MCF7 cells overexpressing PPAR-?/? were significantly smaller, and ligand activation of PPAR-?/? caused an even greater reduction in tumor volume as compared with controls. Interestingly, the decrease in MDA-MB-231 tumor size after overexpressing PPAR-?/? and ligand activation of PPAR-?/? correlated with increased necrosis. These data show that ligand activation and/or overexpression of PPAR-?/? in two human breast cancer cell lines inhibits relative breast cancer tumorigenicity and provide further support for the development of ligands for PPAR-?/? to specifically inhibit breast carcinogenesis. These new cell-based models will be invaluable tools for delineating the role of PPAR-?/? in breast cancer and evaluating the effects of PPAR-?/? agonists.

SUBMITTER: Yao PL 

PROVIDER: S-EPMC3981956 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature