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.