P–578 Human pappiloma virus 16,18 genome methylation patterns in subfertile women

Abstract

Abstract Study question A comparison between L1 gene and LCR region methylation status of HPV16 and HPV18 viruses in subfertile women, investigating HPV methylation pattern in cervical cancer and asymptomatic HPV infection. Summary answer CpG methylation was more frequent in L1 gene compared to LCR in both HPV types. Methylation levels were associated with the grade of cervical dysplasia. What is known already HPV infection is a common sexually transmitted disease, related to genital warts and cancer. DNA methylation as a dynamic and strictly controlled process can be involved in numerous cellular processes, cell differentiation, gene expression regulation and genome reprogramming. Human pappiloma virus genome epigenetic alterations may play a key role in HPV life cycle as well as in the oncogenic process in general. However, whether the prevalence of high risk HPV is correlated with female infertility, has yet to be elucidated. Study design, size, duration From January 2015 to December 2019, about 2505 infertile couples were referred to the Human Reproduction Unit of Ioannina University Hospital. A total of 212 clinical and laboratory data from female partners were included in the study. Participants/materials, setting, methods Cervical smears were studied for HPV DNA methylation. CpG methylation was compared among L1 gene and LCR region in both HPV types. A bisulfite modification assay followed by DNA amplification and sequencing was performed to analyse HPV16 and HPV18 genome. Main results and the role of chance In HPV16 types, L1 gene and promoter region indicated high methylation levels in cervical cancer cases. LCR regions methylation levels ranged from 0,5% to 24,2% in asymptomatic HPV16 infection or cervical intraepithelial neoplasia and cervical cancer, respectively. As for L1 gene, the differences between asymptomatic HPV16 infection and cervical cancer cases were statistically significant (P = 0.003). In HPV18 types, L1 gene was methylated in cervical intraepithelial neoplasia and cervical cancer cases. Promoter region methylation levels were high in cervical cancer cases while LCR region methylation levels were low. Limitations, reasons for caution Main limitation is the relatively small size of the collected samples. Wider implications of the findings: HPV genome investigation, as for methylation status, may lead to better understanding and earlier diagnostics of cervical pathology in infertile population. These observations point out the importance of fertility preservation in women at high risk for cervical neoplasia. Trial registration number Not applicable