HUMAN PAPILLOMAVIRUS DNA AND ABNORMAL P53 EXPRESSION IN CARCINOMA OF THE URINARY-BLADDER

In this study we analysed 47 bladder carcinomas for the presence of DN A-HPV subtypes 6, 11, 16, 18, 31 and 33 by nucleic acid in situ hybrid ization, and for the abnormal accumulation of p53 protein by immunohis tochemistry. HPV DNA was found in 27/47 (57%) bladder carcinomas, with multiple subtypes in 20 cases. In squamous cell carcinoma (SCC), HPV DNA was only detected in the superficial layer of the neoplastic epith elium and was found mainly in the nuclear compartment. In contrast, in transitional cell carcinoma (TCC), HPV DNA was also found in deeper p arts of the tumour. In about half the cases it was mainly found in the cytoplasmic compartment. In SCC, the HPV DNA labelling occurred in ko ilocytic cells, while no such association was found in TCC. Abnormal a ccumulation of p53 protein was found in 24/47 (51%) carcinomas. p53 po sitivity was found significantly more often in SCC than in TCC (p=0.05 ). Concurrent HPV positivity and abnormal p53 protein accumulation was found in 18 cases, 14 showing the presence of HPV subtypes 16 and/or 18 DNA. The results demonstrate that HPV DNA occurs widely in urinary tract tumours. Unlike in some other carcinomas, there was no inverse r elationship between HPV positivity and abnormal p53 protein accumulati on in bladder carcinomas. Thus HPV infection may play a role in the pa thogenesis of bladder carcinomas by some mechanism other than inactiva tion of the p53 protein.