Primary chemoprevention of endometrial hyperplasia with the peroxisome proliferator-activated receptor gamma agonist rosiglitazone in the PTEN heterozygote murine model

Abstract

PTEN mutations have been implicated in the development of endometrial hyperplasia and subsequent cancer. Peroxisome proliferator-activated receptor gamma (PPAR-gamma) agonists have demonstrated antineoplastic and chemopreventive effects. The purpose of this study was to evaluate the effects of the PPAR-gamma agonist rosiglitazone on both PTEN wild type and PTEN null cell lines and in the PTEN heterozygote((+/-)) murine model. Hec-1-A (PTEN wild type) and Ishikawa (PTEN null) cells were treated with rosiglitazone. Thirty-five female PTEN(+/-) mice were genotyped and placed into one of four groups for treatment for 18 weeks: A) PTEN wild type with 4 mg/kg rosiglitazone, B) PTEN(+/-) mice with vehicle, C) PTEN(+/-) mice with 4 mg/kg rosiglitazone, and D) PTEN(+/-) mice with 8 mg/kg rosiglitazone. Proliferation and apoptosis were measured by bromodeoxyuridine (BrdU) and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling of DNA fragmentation sites assay. Rosiglitazone caused cell growth inhibition in both Hec-1-A and Ishikawa in a dose-dependent manner (P < 0.02 and P < 0.03, respectively). Rosiglitazone also induced apoptosis in both Hec-1-A (P < .001) and Ishikawa (P < .001) cells in a dose-dependent manner. In the murine model, rosiglitazone decreased proliferation of the endometrial hyperplastic lesions (B vs C; 39.7% vs 9.3% and B vs D; 39.7% vs 4.2%; P < 0.0001) and increased apoptosis of glandular endometrial epithelial cells (B vs C; 2.8% vs 22.4%; P < 0.0001 and B vs D; 2.8% vs 30.2%; P = 0.003). PPAR-gamma agonist rosiglitazone inhibits proliferation and induces apoptosis in both PTEN intact and PTEN null cancer cell lines and in hyperplastic endometrial lesions in the PTEN(+/)(-)murine model.