title: Altered methylation of the DNA repair gene MGMT is associated with neural tube defects.
abstract: DNA repair is critical for proper embryogenesis, and altered expression of DNA repair genes has been associated with neural tube defects (NTDs). The expression of DNA repair enzymes may be controlled, in part, by methylation of the promoter region. To assess whether disturbed promoter methylation pattern increases the incidence of NTDs, we employed methylation specific-multiplex ligation-dependent probe amplification (MS-MLPA) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to quantify the methylation levels of multiple promoter CpG sites in normal human embryos and embryos with NTDs. Of the total seven DNA repair genes, two genes (MGMT, MSH6) were examined as having disturbed methylation levels by MS-MLPA kit, while only one gene was confirmed with a significant alternated methylation pattern by MALDI-TOF MS. In our research, methylation profiling of the DNA repair gene O                         (6)-methylguanine-DNA methyltransferase (MGMT) showed gender difference in embryogenesis. Comparison of MGMT promoter methylation revealed that hypomethylation was associated with an increased risk for cephalic malformations, especially with female embryos (Adjusted Odds Ratio = 8.250). The majority of individual CpG units within the promoter demonstrated hypomethylation. Meanwhile, the expression of MGMT was proven to increase significant in female cases. These results underscore the role of stable promoter methylation in the DNA repair enzymes MGMT for proper embryogenesis.
authors.affiliation: Department of Pediatrics, Mattel Children's Hospital, University of California, Los Angeles, CA 90095-1741, USA.
authors.forename: Susanna
authors.initials: S
authors.lastname: Tran
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Le
authors.forename: Jing
authors.initials: J
authors.lastname: Guan
authors.forename: Lihua
authors.initials: L
authors.lastname: Wu
authors.forename: Jizhen
authors.initials: J
authors.lastname: Zou
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wang
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Chen
authors.forename: Lingling
authors.initials: L
authors.lastname: Cai
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Lu
authors.forename: Huizhi
authors.initials: H
authors.lastname: Zhao
authors.forename: Jin
authors.initials: J
authors.lastname: Guo
authors.forename: Yihua
authors.initials: Y
authors.lastname: Bao
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Zheng
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
mesh_terms: D019175:DNA Methylation / Q000235:genetics*; D015254:DNA Modification Methylases / Q000235:genetics*; D004260:DNA Repair / Q000235:genetics*; D045643:DNA Repair Enzymes / Q000235:genetics*; D047108:Embryonic Development / Q000235:genetics*; D005260:Female; D005333:Fetus / Q000502:physiology; D006801:Humans; D008297:Male; D009436:Neural Tube Defects / Q000235:genetics*; D025521:Tumor Suppressor Proteins / Q000235:genetics*
chemical_list: D025521:Tumor Suppressor Proteins; D015254:DNA Modification Methylases; C515491:MGMT protein, human; D045643:DNA Repair Enzymes
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