Department of Gynaecology, Obstetrics and Gynecology, Hospital of Fudan University, Shanghai, China.
Med Hypotheses. 2013 May;80(5):679-83. doi: 10.1016/j.mehy.2013.01.025. Epub 2013 Mar 13.
Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the metabolism of folate. The single nucleotide polymorphism (SNP), C677T (Ala>Val, rs1801133), has been confirmed to decrease the enzyme activity. The association between C677T and cervical cancer susceptibility has been widely studied. However, the results were inconsistent. In order to elucidate the role of this SNP in cervical cancer, a meta-analysis was conducted.
The literature search was performed using the following databases: PubMed, Embase and ISI Web of Science up to December 2012. The effect of association was indicated as crude odds ratio (OR) with the corresponding 95% confidence interval (CI).
Six studies including 1431 cases and 1915 controls explored C677T genotypes were involved in this meta-analysis. Overall meta-analysis showed that C677T polymorphism increased cervical cancer risk in the complete over-dominant model (random-effect OR=1.33, 95% CI: 1.00-1.77, I(2)=69%). After excluding one study which showed apparent heterogeneity, the heterogeneity disappeared. The meta-analysis of five studies including 1231 cases and 1715 controls showed the fixed-effect OR reached 1.20 (95% CI: 1.03-1.40, I(2)=0) as (TT+CC) in the complete over-dominant model.
C677T polymorphism of MTHFR gene may increase the risk of cervical cancer in the complete over-dominant model. The association merits replicating and validating in further studies.
亚甲基四氢叶酸还原酶（MTHFR）是叶酸代谢的关键酶。单核苷酸多态性（SNP）C677T（Ala>Val，rs1801133）已被证实降低了酶的活性。C677T 与宫颈癌易感性的关系已被广泛研究。然而，结果并不一致。为了阐明该 SNP 在宫颈癌中的作用，进行了荟萃分析。
使用以下数据库进行文献检索：PubMed、Embase 和 ISI Web of Science，截至 2012 年 12 月。关联的效应以粗比值比（OR）及其相应的 95%置信区间（CI）表示。
共有 6 项研究包括 1431 例病例和 1915 例对照，探讨了 C677T 基因型，纳入了本次荟萃分析。总体荟萃分析显示，C677T 多态性在完全超显性模型中增加了宫颈癌的发病风险（随机效应 OR=1.33，95%CI：1.00-1.77，I²=69%）。排除一项存在明显异质性的研究后，异质性消失。五项研究包括 1231 例病例和 1715 例对照的荟萃分析显示，在完全超显性模型中，（TT+CC）固定效应 OR 达到 1.20（95%CI：1.03-1.40，I²=0）。
MTHFR 基因 C677T 多态性可能在完全超显性模型中增加宫颈癌的发病风险。该关联值得在进一步的研究中进行复制和验证。
