Abstract 2294: Pregnancy changes the DNA methylation profile of the breast in postmenopausal women

Recently, we have described that the breast of parous postmenopausal women exhibits a specific gene expression profile induced by full term pregnancy (FTP) [Belitskaya-Levy, I. et al. 2011 and Peri, S. et al. 2012], which is centered on chromatin remodeling [Russo, J. 2012]. In order to better understand the molecular mechanism of gene regulation induced by FTP, we have investigated the DNA methylation profile in breast core needle biopsies of five nulliparous (NP) and five parous (P) postmenopausal women between the ages of 50 and 69. DNA was extracted from core needle biopsies and highly methylated fragments of the DNA were separated from the un-methylated DNA using MBD-Capture. The hypermethylated DNA was then sequenced using the Illumina system. Image analysis and base calling were performed with the standard Illumina pipeline, and the reads were aligned to human reference genome (hg18). Differentially methylated regions (DMR) were identified by comparing the differences of averaged methylation values between P and NP samples using Student's t-test (P Citation Format: Julia Santucci-Pereira, Colleen O'Malley, Ricardo López de Cicco, Nameer B. Kirma, Tim H. Huang, Joseph Liu, Eric A. Ross, Michael Slifker, Suraj Peri, Irma H. Russo, Pal Bordas, Per Lenner, Göran Hallmans, Paolo Toniolo, Jose Russo. Pregnancy changes the DNA methylation profile of the breast in postmenopausal women. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2294. doi:10.1158/1538-7445.AM2014-2294