Klin Onkol 2000; 13(4): 126-130.
Summary: lntroduction: Human papillomaviruses (HPV) are involved in carcinogenesis of uterine cervical epitheliurn. Functional inactivation of p53 protein, which is mediated by the HPV protein E6, is thought to be an important feature of trus process. We tested the immunohistochemical approach to demonstrate the HPV 16 and 18 E6 protein expression in cervical dysplasias and carcinomas with HPV presence detected by in situ hybridisation. Material and methods: The study was performed in paraffin embedded biopsy samples from 36 patients consisting of 17 cervical carcinomas and 19 dysplastic lesions ranging from CIN I to CIN III. The in situ hybridisation of HPV DNA was done using a commercial kit (Biohit), containing a screening (pan HPV) probe and single type specific probes. The monoclonal antibody against E6 of HPV types 16 and 18 was used for immunohistochemistry. The antibody detectection was amplified using biotinylated tyramide. Results: The in situ hybridisation of pan-HPV probe was positive in 35 cases. The further evaluation of the HPV type was successful in 21 cases, 19 of them containing HPV 16 or 18. The E6 protein immunostaining was successfully detected in 11 cases, all of them being positive for the HPV 16 or 18 specific DNA sequences. Conclusion: The immunostaining of HPV 16 and 18 E6 protein is possible and can be highly specific. The sensitivity of trus method is not completely satisfactory, despite of highly sensitive biotynylated tyramide detection used. The E6 immunohistochemistry might possibly replace in situ hybridisation methods in some instances. The level of E6 expression could be of interest as a marker estimating degree of derangement of p53-mediated cell response to radiotherapy and chemosenstivity of these carcinomas.
