title: [Correlation of insulin-like growth factor 1 expression in placenta with DNA methylation and fetal macrosomia].
abstract: OBJECTIVE
  To explore the correlation between methylation of insulin-like growth factor 1 (IGF-1) gene promoter and its placenta-specific expression and fetal macrosoma.
  
  
  METHODS
  One hundred twenty nine healthy pregnant women were recruited between April 2011 and March 2012. Baseline data were collected with self-report questionnaires. Real-time quantitative PCR was used to determine the expression of IGF-1 mRNA in the placenta. Methylation level of the IGF 1 gene was determined with matrix-assisted laser desorption/ionization-time of flight mass spectrometry.
  
  
  RESULTS
  The expression of IGF-1 in placenta and its methylation level showed no significant difference between macrosomic fetuses and controls. No linear correlation was found between IGF-1 mRNA expression and methylation level of IGF-1 promoter (r=0.128, P=0.295). IGF-1 promoter region in placenta showed a hypomethylation status. However, a positive correlation was found between IGF-1 expression and birth weight below 4260 g (r=0.264, P=0.022). The expression of IGF-1 mRNA was significantly higher in those with a birth weight below 4260 g, which suggested that placental IGF-1 expression may contribute to increased birth weight. In regard to fetal overgrowth, however, there seemed to be a negative correlation in which placental IGF-1 expression was downregulated to limit fetal overgrowth.
  
  
  CONCLUSIONS
  No linear correlation was found between placental IGF-1 expression and methylation level of IGF-1 promoter with a hypomethylation status. The contribution of placental IGF-1 expression to birth weight is bidirectional. Increased expression seems to promote fetal growth, while decreased expressions may curb overgrowth, therefore control fetal growth in a relatively normal range.
authors: Department of Preventive Medicine, School of Environmental Science and Public Health, Wenzhou Medical University, Wenzhou, Zhejiang 325035, P. R. China. Email: xjyang@wzmc.edu.cn.
authors: Jitai
authors: J
authors: Zhang
authors: Kele
authors: K
authors: Wu
authors: Xinyun
authors: X
authors: Xu
authors: Ziwei
authors: Z
authors: Liu
authors: Chong
authors: C
authors: Lin
authors: Yuhuan
authors: Y
authors: Wang
authors: Hongtao
authors: H
authors: Yan
authors: Xinyun
authors: X
authors: Yang
mesh_terms: D001724:Birth Weight; D019175:DNA Methylation; D005260:Female; D005320:Fetal Macrosomia / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I