title: Plasma B vitamins and LINE-1 DNA methylation in leukocytes of patients with a history of colorectal adenomas.
abstract: METHODS
  Low concentrations of folate, other B vitamins, and methionine are associated with colorectal cancer risk, possibly by changing DNA methylation patterns. Here, we examine whether plasma concentrations of B vitamins and methionine are associated with methylation of long interspersed nuclear element-1 (LINE-1) among those at high risk of colorectal cancer, i.e. patients with at least one histologically confirmed colorectal adenoma (CRA) in their life.
  
  
  RESULTS
  We used LINE-1 bisulfite pyrosequencing to measure global DNA methylation levels in leukocytes of 281 CRA patients. Multivariable linear regression was used to assess associations between plasma B vitamin concentrations and LINE-1 methylation levels. Plasma folate was inversely associated with LINE-1 methylation in CRA patients, while plasma methionine was positively associated with LINE-1 methylation.
  
  
  CONCLUSIONS
  This study does not provide evidence that in CRA patients, plasma folate concentrations are positively related to LINE-1 methylation in leukocytes but does suggest a direct association between plasma methionine and LINE-1 methylation in leukocytes.
authors.affiliation: Department of Epidemiology, Biostatistics, and HTA, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
authors.forename: Audrey Y
authors.initials: AY
authors.lastname: Jung
authors.forename: Akke
authors.initials: A
authors.lastname: Botma
authors.forename: Carolien
authors.initials: C
authors.lastname: Lute
authors.forename: Henk J
authors.initials: HJ
authors.lastname: Blom
authors.forename: Per M
authors.initials: PM
authors.lastname: Ueland
authors.forename: Gry
authors.initials: G
authors.lastname: Kvalheim
authors.forename: Øivind
authors.initials: Ø
authors.lastname: Midttun
authors.forename: Fokko
authors.initials: F
authors.lastname: Nagengast
authors.forename: Wilma
authors.initials: W
authors.lastname: Steegenga
authors.forename: Ellen
authors.initials: E
authors.lastname: Kampman
mesh_terms: D000236:Adenoma / Q000235:genetics / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D003430:Cross-Sectional Studies; D019175:DNA Methylation / Q000187:drug effects*; D005260:Female; D005492:Folic Acid / Q000097:blood; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D007962:Leukocytes / Q000187:drug effects* / Q000378:metabolism; D008019:Life Style; D016014:Linear Models; D020084:Long Interspersed Nucleotide Elements / Q000187:drug effects*; D008297:Male; D008715:Methionine / Q000097:blood; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014803:Vitamin B Complex / Q000097:blood*; D055815:Young Adult
chemical_list: D014803:Vitamin B Complex; D005492:Folic Acid; D008715:Methionine; C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2)