Racial Disparities in Epigenetic Aging of the Right vs Left Colon
Menée à partir de l'analyse du niveau de méthylation de l'ADN d'échantillons de tissus coliques de 128 personnes saines, cette étude examine, en fonction de l'origine ethnique (européenne ou africaine), la différence d'âge épigénétique entre le côlon droit et le côlon gauche
There are well-documented racial differences in age-of-onset and laterality of colorectal cancer. Epigenetic age acceleration is postulated to be an underlying factor. However, comparative studies of side-specific colonic tissue epigenetic aging are lacking. Here, we performed DNA methylation analysis of matched right and left biopsies of normal colon from 128 individuals. Among African Americans (n = 88), the right colon showed accelerated epigenetic aging as compared to individual-matched left colon (1.51 years; 95% CI = 0.62 to 2.40 years; two-sided P = .001). In contrast, among European Americans (n = 40), the right colon shows remarkable age deceleration (1.93 years; 95% CI = 0.65 to 3.21 years; two-sided P = .004). Further, epigenome-wide analysis of DNA methylation identifies a unique pattern of hypermethylation in African American right colon. Our study is the first to report such race and side-specific differences in epigenetic aging of normal colon, providing novel insight into the observed younger age-of-onset and relative preponderance of right-side colon neoplasia in African Americans.
Journal of the National Cancer Institute , résumé, 2019