Expression of Pigment Epithelium-derived Factor in Bladder Tumour Is Correlated with Interleukin-8 yet Not with Interleukin-1α

Pigment epithelium-derived factor (PEDF) is an antiangiogenic factor which is effective in tumour inhibition in a variety of tumours and has not yet been studied in bladder tumour before. In this study the expression of PEDF, interleukin-1α (IL-1α) and -8 (IL-8) in bladder tumours was investigated. Immunohistochemistry was performed on 64 bladder tumour and 23 normal uroepithelium samples. Expression change of the factors was compared with clinicopathological parameters. Correlations between PEDF, IL-1α and IL-8 were analyzed. None of the factors was in relation to gender, tumour occurrence, and size or onset pattern. PEDF (P=0.014) and IL-1α (P=0.049) expression was down-regulated with grade progression. PEDF expression was lower in normal uroepithelium than in papillary urothelial neoplasm of low malignant potential (PUNLMP) (P=0.000) and carcinoma (P=0.009) whilst IL-1α (P=0.000 and P=0.000 respectively) and IL-8 (P=0.000 and P=0.023 respectively) expression was higher in the same grouping. PEDF expression had a negative correlation with IL-8 in PUNLMP (P=0.049, r=-0.578) as well as in tumour grouping (P=0.033, r=-0.276). Deranged expressional change of PEDF, IL-1α and IL-8 could be in relation to loss of differentiation from normal uroepithelium to papillary lesion and eventually to carcinoma.