Correlated expression of peroxisome proliferator-activated receptor γ with high histologic grade and basal type in invasive ductal carcinoma of the breast

Abstract

Backgroud and aim: Peroxisome proliferator-activated receptor γ (PPARγ) is one of the ligand-activated transcription factors belonging to the nuclear hormone receptor family. The protein is expressed in various kinds of tumor and has been implicated as a tumor suppressor in most cancers. We aimed to understand the role of PPARγ in breast cancer. Methods: The expression of PPARγ in 288 cases of invasive ductal carcinoma was examined using tissue microarray and immunohistochemistry. Results: PPARγ immunoreactivity was detected in 21.5% of cases and significantly associated with expression of EGFR and ki-67 (P = 0.008; P = 0.046). PPARγ expression was correlated with high histological grade and basal type (P ≤ 0.001; P =0.009).Conclusions: PPARγ expressionis related to poor prognostic factors of breast cancer. It is considered that PPARγ has evident tumor promoting properties in vivo, but receptor-independent effects of PPARγ ligands may compound its biologic effects in cancer. A better understanding of action mechanisms of the activated PPARγ is required. © 2009 The Korean Society for Cytopathology, The Korean Society for Legal Medicine, The Korean Society of Oral and Maxillofacial Pathology, The Korean Society of Pathologists, The Korean Society of Toxicological Pathology, The Korean Society of Veterinary Pathology and Blackwell Publishing Asia Pty Ltd.