Christensen B
Seksjon for farmakologi Institutt for klinisk biologi Universitetet i Bergen.
Tidsskr Nor Laegeforen. 1996 Jan 20;116(2):250-4.
The biochemical role of folate is in the interconversion of one-carbon units in intermediary metabolism; a process in which a methyl group is formed de novo. The methyl group is subsequently transferred to adenosylmethionine, which is an important methyl donor in the methylation of DNA. A negative correlation exists between the intake of folate in pregnancy and the occurrence of neural tube defects and certain malignant brain tumours in children. Numerous clinical studies have pointed to an association between folate status in adults and both the occurrence of cancer and the premalignant changes, cervical dysplasia, bronchial metaplasia, and colorectal adenomas. Folate deficiency may cause chromosomal damage, due to impaired DNA synthesis or repair. Moreover, decreased production of adenosylmethionine may influence the expression of developmental genes and of oncogenes and/or tumour suppressor genes through disturbed methylation of DNA.
叶酸的生化作用在于中间代谢中一碳单位的相互转化；这是一个从头合成甲基基团的过程。随后，甲基基团被转移至腺苷甲硫氨酸，后者是DNA甲基化过程中重要的甲基供体。孕期叶酸摄入量与儿童神经管缺陷及某些恶性脑肿瘤的发生之间存在负相关。众多临床研究表明，成年人的叶酸状态与癌症发生以及癌前病变、宫颈发育异常、支气管化生和结肠直肠腺瘤之间存在关联。叶酸缺乏可能因DNA合成或修复受损而导致染色体损伤。此外，腺苷甲硫氨酸产量降低可能通过DNA甲基化紊乱影响发育基因、癌基因和/或肿瘤抑制基因的表达。
