Associations between Methylation of Paternally Expressed Gene 3 (PEG3), Cervical Intraepithelial Neoplasia and Invasive Cervical Cancer

Abstract

Cytology-based screening for invasive cervical cancer (ICC) lacks sensitivity and specificity to discriminate between cervical intraepithelial neoplasia (CIN) likely to persist or progress from cases likely to resolve. Genome-wide approaches have been used to identify DNA methylation marks associated with CIN persistence or progression. However, associations between DNA methylation marks and CIN or ICC remain weak and inconsistent. Between 2008–2009, we conducted a hospital-based, case-control study among 213 Tanzania women with CIN 1/2/3 or ICC. We collected questionnaire data, biopsies, peripheral blood, cervical scrapes, Human papillomavirus (HPV) and HIV-1 infection status. We assessed PEG3 methylation status by bisulfite pyrosequencing. Multinomial logistic regression was used to estimate odds ratios (OR) and confidence intervals (CI 95%) for associations between PEG3 methylation status and CIN or ICC. After adjusting for age, gravidity, hormonal contraceptive use and HPV infection, a 5% increase in PEG3 DNA methylation was associated with increased risk for ICC (OR = 1.6; 95% CI 1.2–2.1). HPV infection was associated with a higher risk of CIN1-3 (OR = 15.7; 95% CI 5.7–48.6) and ICC (OR = 29.5, 95% CI 6.3–38.4). Infection with high risk HPV was correlated with mean PEG3 differentially methylated regions (DMRs) methylation (r = 0.34 p<0.0001), while the correlation with low risk HPV infection was weaker (r = 0.16 p = 0.047). Although small sample size limits inference, these data support that PEG3 methylation status has potential as a molecular target for inclusion in CIN screening to improve prediction of progression.Impact statementWe present the first evidence that aberrant methylation of the PEG3 DMR is an important co-factor in the development of Invasive cervical carcinoma (ICC), especially among women infected with high risk HPV. Our results show that a five percent increase in DNA methylation of PEG3 is associated with a 1.6-fold increase ICC risk. Suggesting PEG3 methylation status may be useful as a molecular marker for CIN screening to improve prediction of cases likely to progress.

Epigenetic regulation of Newborns’ imprinted genes related to gestational growth: patterning by parental race/ethnicity and maternal socioeconomic status

“…Chromosomal locations, bisulfite pyrosequencing conditions, and assay validation are reported elsewhere 59 61. Briefly, genomic DNA (800 ng) was modified with sodium bisulfite, which converts unmethylated cytosines to uracils while leaving methylated cytosines unchanged.…”

Decorin as a multivalent therapeutic agent against cancer

“…Previously, Peg3 has been implicated in regulating stem cell progenitors [144,145], mediating p53-dependent apoptosis of myogenic and neural lineages [146-150], and maternal/paternal behavioral patterns [151,152]. Peg3 has been implicated in the pathogenesis of cervical and ovarian carcinoma as its expression is frequently lost via promoter hypermethylation and/or loss of heterozygosity [153-156]. Thus, Peg3 is considered a bona fide tumor suppressor [157].…”

Erythrocyte folate concentrations, CpG methylation at genomically imprinted domains, and birth weight in a multiethnic newborn cohort

“…Pyrosequencing assay design, genomic coordinates, assay conditions and assay validation have been previously described. 73,76 Percent methylation for each CpG cytosine was determined using Pyro Q-CpG Software (Qiagen). DMRs in which DNA methylation was measured include two regions regulating the IGF2/H19 imprinted domain (one upstream of the imprinted IGF2 promoters and one upstream of the H19 locus at the imprint center), two regions regulating the DLK1/MEG3 imprinted domain (the imprint center intergenic to DLK1 and MEG3 and the DMR within the MEG3 promoter region, the maternally methylated PEG3 promoter region, the maternally methylated MEST promoter region, the maternally methylated PEG10 promoter region from which SGCE is also transcribed in the opposite direction, the maternally methylated NNAT promoter and the maternally methylated PLAGL1 promoter.…”