Association between PEG3 DNA methylation and high-grade cervical intraepithelial neoplasia

Background Epigenetic mechanisms are hypothesized to contribute substantially to the progression of cervical intraepithelial neoplasia (CIN) to cervical cancer, although empirical data are limited. Methods Women (n = 419) were enrolled at colposcopic evaluation at Duke Medical Center in Durham, North Carolina. Human papillomavirus (HPV) was genotyped by HPV linear array and CIN grade was ascertained by biopsy pathologic review. DNA methylation was measured at differentially methylated regions (DMRs) regulating genomic imprinting of the IGF2/H19, IGF2AS, MESTIT1/MEST, MEG3, PLAGL1/HYMAI, KvDMR and PEG10, PEG3 imprinted domains, using Sequenom-EpiTYPER assays. Logistic regression models were used to evaluate the associations between HPV infection, DMR methylation and CIN risk overall and by race. Results Of the 419 participants, 20 had CIN3+, 52 had CIN2, and 347 had <= CIN1 (CIN1 and negative histology). The median participant age was 28.6 (IQR:11.6) and 40% were African American. Overall, we found no statistically significant association between altered methylation in selected DMRs and CIN2+ compared to <= CIN1. Similarly, there was no significant association between DMR methylation and CIN3+ compared to <= CIN2. Restricting the outcome to CIN2+ cases that were HR-HPV positive and p16 staining positive, we found a significant association with PEG3 DMR methylation (OR: 1.56 95% CI: 1.03-2.36). Conclusions While the small number of high-grade CIN cases limit inferences, our findings suggest an association between altered DNA methylation at regulatory regions of PEG3 and high grade CIN in high-risk HPV positive cases.

Automated summary

There was a significant association found between altered DNA methylation at regulatory regions of the PEG3 and high-grade CIN in high-risk HPV positive cases, while no significant association was found between other DMRs and CIN risk. The number of high-grade CIN cases in the study was limited, which may affect the generalizability of the findings.