INHIBITION OF ANTIPROLIFERATIVE FACTOR (APF) ACTIVITY IN BLADDER EPITHELIAL CELLS BY TWO SYNTHETIC APF DERIVATIVES

enzyme-linked immunosorbent assay (ELISA). HB-EGF levels in the urine of 30 patients with interstitial cystitis and 20 control samples from patients with incontinence were also studied using ELISA. RESULTS: Tissue cultured normal human urothelial cells showed a strong response (up to 9-fold) to ATRA treatment as shown in Figure 1. Treatment of ureteral segments in organ culture also increased the HB-EGF levels in the medium from a basal level of 120 picograms/ml HB-EGF to 225 picogramss/ml of HB-EGF. Urinary levels of HB-EGF were not significantly different in samples from patients with interstitial cystitis compared to incontinent patient controls, although a subset of the IC patients (8/30) had less than 450 pg/ml/mg creatinine while only 2/20 controls showed such low levels. CONCLUSIONS: Treatment with ATRA increased expression of HB-EGF produced by urothelial cells. HB-EGF levels in urine from IC patients are not consistently low. However, a subset of IC patients appear to have much lower HB-EGF levels. These results suggest that ATRA should be explored for possible therapeutic value in interstitial cystitis.