The role of peroxisome proliferator-activated receptor gamma in bladder cancer in relation to angiogenesis and progression.

Peroxisome proliferator-activated receptor gamma (PPAR gamma) immunohistochemical expression was analyzed in 75 human bladder tumor specimens, where the expression of some angiogenic factors, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived endothelial cell growth factor (PDECGF), and tumor progression markers, such as epidermal growth factor receptor (EGFr), p16, mutated p53, and normal pRB, were also analyzed. The results were then compared to the clinical and pathological characteristics of the disease. PPAR gamma was expressed more significantly in papillary tumors than in solid cancers, and its presence was associated with statistical significance to low incidence of tumor recurrence or progression. This significant association was observed also when PPAR gamma was expressed in the presence of PDECGF, which resulted, when considered alone, to an angiogenic factor typical of solid cancers and appeared related to poor prognosis. In the presence of bFGF, on the contrary, PPAR gamma expression no longer resulted to a significant association with low incidence of tumor recurrence or progression, suggesting a possible worsening role of this angiogenic factor, typical of papillary cancers, in its interaction with PPAR gamma.