Kafadar Ali Metin, Yilmaz Hulya, Kafadar Didem, Ergen Arzu, Zeybek Umit, Bozkurt Nilufer, Kuday Cengiz, Isbir Turgay
Department of Neurosurgery, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey.
Anticancer Res. 2006 May-Jun;26(3B):2445-9.
Methylenetetrahydrofolate reductase (MTHFR) plays a role in DNA biosynthesis, methylation and repair in actively dividing cells by acting on folate metabolism. A common C677T polymorphism in the gene for MTHFR leads to an enzyme with decreased activity. MTHFR polymorphisms have been studied in various cancers but not in primary brain tumors. The purpose of this case-control study was to explore a possible association between MTHFR C677T polymorphism and primary brain tumors.
The MTHFR C677T genotype was determined in 74 patients with histologically-verified primary brain tumors and 98 cancer-free control subjects.
The MTHFR 677T variant genotype was observed in 49% of cases and 46% of controls. Although the difference was not significant (p =0. 194), the homozygous TT genotype was found at a higher frequency in high-grade glioma (HGG) patients compared to controls (15.4% and 7.1%, respectively). The MTHFR genotype was not associated with meningioma patients. Defining patients with the CC genotype as reference, the relative risk of HGG for subjects with the T allele (CT+ TT genotype) was 1.17.
In spite of the established effect of the MTHFR 677 TT genotype on DNA hypomethylation with concomitant inadequate folate levels, the MTHFR 677 TT genotype is not associated with individual susceptibility to HGG.
亚甲基四氢叶酸还原酶(MTHFR)通过作用于叶酸代谢,在活跃分裂细胞的DNA生物合成、甲基化和修复过程中发挥作用。MTHFR基因中常见的C677T多态性会导致该酶活性降低。MTHFR多态性已在多种癌症中进行了研究,但在原发性脑肿瘤中尚未开展相关研究。本病例对照研究的目的是探讨MTHFR C677T多态性与原发性脑肿瘤之间可能存在的关联。
对74例经组织学确诊的原发性脑肿瘤患者和98例无癌对照者进行MTHFR C677T基因型检测。
49%的病例和46%的对照者检测到MTHFR 677T变异基因型。虽然差异不显著(p = 0.194),但与对照相比,高级别胶质瘤(HGG)患者中纯合TT基因型的频率更高(分别为15.4%和7.1%)。MTHFR基因型与脑膜瘤患者无关。将CC基因型患者定义为参照,携带T等位基因(CT + TT基因型)的受试者患HGG的相对风险为1.17。
尽管已证实MTHFR 677 TT基因型在叶酸水平不足时会导致DNA低甲基化,但MTHFR 677 TT基因型与个体对HGG的易感性无关。