engleski

Detection of Integrated Forms of HPV16 DNA Regarding Different Grade of Cervical Intraepithelial Neoplasia (CIN)

OBJECTIVE: Integration of HPV DNA in the genome of the host cell is one of the key events in the development of cervical cancer. Most cervical carcinoma cell lines and samples of cervical cancer tissues contain integrated forms of HPV DNA. During integration in the majority of cases viral genome breaks within E1 and/or E2 regions. Herein, in order to determine if the viral integration is a relevant marker of progression of the precancerous lesions of cervical epithelia we investigated the frequency of viral integration by analysis of the break within E1 and/or E2 region in DNA samples of cervical scrapes from women with different grade of cervical intraepithelial neoplasia (CIN). METHODS: DNA isolated from cervical scrapes of 189 women with CIN I-III (cytological classification), each positive for HPV 16 DNA, by means of polymerase chain reaction (PCR) of the E6/7 region, were selected for further analysis. To determine the frequency of the integrated forms of HPV 16 DNA we investigated the break of the E1 and/or E2 region by means of multiplex PCR with primers specific for these regions of the viral genome. RESULTS: In average, integrated forms of HPV16 DNA were detected in 23 of 189 (12.2 %) cervical samples. The integration was observed in 17.3% CIN III samples, while the CIN I and CIN II samples had the integration rate of 9.1% and 10.9%, respectively. Furthermore, in the group of samples with undetermined cytology we detected 10.3% of integrated HPV 16 DNA, as well. DISCUSSION: The highest percentage of integration of HPV 16 DNA was found in the CIN III samples, as expected. However, there is no statistically significant difference between different CIN grades and HPV 16 DNA integration. Thus, the integration as such could not be considered as a consistent marker of CIN progression.

Human papillomaviruses (HPV); integration

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