Integration of human papilloma virus as a monoclonal event in cervical cancer

Introducion:

Integration of human papilloma viruses into the host genome is a common event during carcinogenesis in cervical cancer.

Little is known about the background of this event. There are several facts which emphasize that viral integration may play a central role in the multistep process of carcinogenesis. Particularly the observation that precursors of cervical cancer frequently carry viral DNA sequences integrated in the host genome and that the frequency of viral integration is associated with the degree of dysplasia of precursor lesions indicate an early event in the development of malignancy. The common loss of the E2 gene which is frequently/regularly found in case of viral integration and the resultant overexpression of the E6 and E7 oncogenes highlight the importance of this event for the resulting inactivation of pRB and p53.

In this study the integration pattern of HPV in tumor cells of a patient suffering from cervical cancer was explored via DIPS PCR Detection of Integrated (Papillomavirus Sequencees).

Performing an in situ PCR procedure we were able demonstrate an identical integration site in all tumor cells. These data strongly support the hypothesis that HPV induced carcinogenesis is a clonal event within the process of tumorigenesis. Due to that we postulate that viral integration is an early event is the cascade of carcinogenesis of cervical cancer.