caa a22 4500 378881450 CHVBK 20180305123432.0 cr unu---uuuuu 161128e20030807xx s 000 0 eng 10.1515/CCLM.2003.155 doi (NATIONALLICENCE)gruyter-10.1515/CCLM.2003.155 Effects of Vitamin B12 and Folate Deficiencies on DNA Methylation and Carcinogenesis in Rat Liver [Elektronische Daten] [Laurent Brunaud, Jean-Marc Alberto, Ahmet Ayav, Philippe Gérard, Farès Namour, Laurent Antunes, Marc Braun, Jean-Pierre Bronowicki, Laurent Bresler, Jean-Louis Guéant] Deficiencies of the major dietary sources of methyl groups, methionine and choline, lead to the formation of liver cancer in rodents. The most widely investigated hypothesis has been that dietary methyl insufficiency results in abnormal DNA methylation. Vitamin B12 and folate also play important roles in DNA methylation since these two coenzymes are required for the synthesis of methionine and S-adenosyl methionine, the common methyl donor required for the maintenance of methylation patterns in DNA. The aim of this study was to review the effects of methyl-deficient diets on DNA methylation and liver carcinogenesis in rats, and to evaluate the role of vitamin B12 status in defining carcinogenicity of a methyl-deficient diet. Several studies have shown that a methyl-deficient diet influences global DNA methylation. Evidence from in vivo studies has not clearly established a link between vitamin B12 and DNA methylation. We reported that vitamin B12 and low methionine synthase activity were the two determinants of DNA hypomethylation. Choline- or choline/methionine-deficient diets have been shown to cause hepatocellular carcinoma in 20-50% of animals after 12-24 months. In contrast, the effect of vitamin B12 withdrawal, in addition to choline, methionine and folate, induced hepatocellular carcinoma in less than 5% of Copyright © 2003 by Walter de Gruyter GmbH & Co. KG Medical equipment & techniques nationallicence Medical diagnosis nationallicence Diseases & disorders nationallicence Brunaud Laurent aut Alberto Jean-Marc aut Ayav Ahmet aut Gérard Philippe aut Namour Farès aut Antunes Laurent aut Braun Marc aut Bronowicki Jean-Pierre aut Bresler Laurent aut Guéant Jean-Louis aut Clinical Chemistry and Laboratory Medicine Walter de Gruyter 41/8(2003-08-07), 1012-1019 1434-6621 41:8<1012 2003 41 cclm https://doi.org/10.1515/CCLM.2003.155 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/CCLM.2003.155 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Brunaud Laurent aut NATIONALLICENCE 700 1- Alberto Jean-Marc aut NATIONALLICENCE 700 1- Ayav Ahmet aut NATIONALLICENCE 700 1- Gérard Philippe aut NATIONALLICENCE 700 1- Namour Farès aut NATIONALLICENCE 700 1- Antunes Laurent aut NATIONALLICENCE 700 1- Braun Marc aut NATIONALLICENCE 700 1- Bronowicki Jean-Pierre aut NATIONALLICENCE 700 1- Bresler Laurent aut NATIONALLICENCE 700 1- Guéant Jean-Louis aut NATIONALLICENCE 773 0- Clinical Chemistry and Laboratory Medicine Walter de Gruyter 41/8(2003-08-07), 1012-1019 1434-6621 41:8<1012 2003 41 cclm CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter