Expression of peroxisome proliferator-activated receptor-γ in colon cancer: Correlation with histopathological parameters, cell cycle-related molecules, and patients' survival

Peroxisome proliferator-activated receptor gamma (PPAR-gamma), a ligand-activated transcription factor, is a key regulator of adipogenic differentiation and glucose homeostasis. PPAR-gamma ligands have recently been demonstrated to affect proliferation and differentiation in cancer cells lines. The aim of the present work was to examine PPAR-gamma expression in colon cancer cases. PPAR-gamma expression was examined immunohistochemically in 86 colon cancer cases and was correlated with clinicopathological parameters, tumor proliferative capacity, cell cycle-related molecule expression, and patient survival. Positive PPAR-gamma immunostaining was prominent in 48 of 86 cases (56%). PPAR-gamma positivity was not correlated with Dukes' stage, histological grade of differentiation, lymph node and liver metastasis, venous invasion, tumor proliferative capacity, or patient survival. A statistically significant correlation was found between PPAR-gamma and the expression of cell cycle-related molecules pRb (P < 0.016), cyclin D1 (P