Open AccessSeasonality Modifies Methylation Profiles in Healthy People
Author(s) -
Fulvio Ricceri,
Morena Trevisan,
Valentina Fiano,
Chiara Grasso,
Francesca Fasanelli,
Chiara Scoccianti,
Laura De Marco,
Anna Gillio-Tos,
Paolo Víneis,
Carlotta Sacerdote
Publication year - 2014
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0106846
Subject(s) - dna methylation , methylation , epigenetics , cpg site , biology , seasonality , pyrosequencing , basal (medicine) , genetics , physiology , gene , gene expression , endocrinology , ecology , insulin
DNA methylation is a well-characterized epigenetic modification that plays an important role in the regulation of gene expression. There is growing evidence on the involvement of epigenetic mechanisms in disease onset, including cancer. Environmental factors seem to induce changes in DNA methylation affecting human health. However, little is known about basal methylation levels in healthy people and about the correlation between environmental factors and different methylation profiles. We investigated the effect of seasonality on basal methylation by testing methylation levels in the long interspersed nucleotide element-1 (LINE-1) and in two cancer-related genes ( RASSF1A and MGMT ) of 88 healthy male heavy smokers involved in an Italian randomized study; at enrolment the subjects donated a blood sample collected in different months. Methylation analyses were performed by pyrosequencing. Mean methylation percentage was higher in spring and summer for the LINE1, RASSF1A and MGMT genes (68.26%, 2.35%, and 9.52% respectively) compared with autumn and winter (67.43%, 2.17%, and 8.60% respectively). In particular, LINE-1 was significantly hypomethylated (p = 0.04 or 0.05 depending on the CpG island involved) in autumn and winter compared with spring and summer. Seasonality seems to be a modifier of methylation levels and this observation should be taken into account in future analyses.