c-jun oncogene expression in transitional cell carcinoma of the urinary bladder.

OBJECTIVE: To investigate c-jun oncoprotein expression in transitional cell carcinomas (TCCs) of the urinary bladder and to determine its relationship to tumour grade and stage, and to the expression of epidermal growth factor receptor (EGFR), c-erbB-2 and p53 oncoproteins. MATERIALS AND METHODS: The expression of c-jun was studied using immunohistochemistry in a series of 48 TCCs of known EGFR, c-erbB-2 and p53 status. RESULTS: Forty-four of 48 (92%) tumours showed c-jun specific nuclear immunoreactivity of variable intensity. The intensity of c-jun immunostaining was significantly related to tumour stage (P = 0.009) and EGFR status (P = 0.01). There was no correlation between c-jun oncoprotein expression and c-erbB-2 or p53 immunoreactivity. c-jun expression was not related to clinical outcome in terms of patient survival or rate of tumour recurrence. CONCLUSION: The c-jun oncoprotein is expressed in the majority of TCCs of the urinary bladder. There is a positive association between intense c-jun immunoreactivity and muscle invasive growth, and EGFR positivity in TCCs.