title: Methylation status of human chorionic gonadotropin beta subunit promoter and TFAP2A expression as factors regulating CGB gene expression in placenta.
abstract: OBJECTIVE
  To evaluate mechanisms regulating the expression of CGB genes in placental tissues from uncomplicated pregnancies and chorionic samples from spontaneous miscarriages.
  
  
  METHODS
  Molecular analyses in human samples.
  
  
  METHODS
  Laboratory of molecular biology.
  
  
  METHODS
  Nine placental samples from term deliveries and 21 chorionic samples from miscarriages at 7-13 weeks of gestation.
  
  
  METHODS
  None.
  
  
  METHODS
  The expression level of CGBs and genes encoding SP1, SP3, and AP2 transcription factors was analyzed using quantitative polymerase chain reaction (qPCR). The methylation status of the CGBs' promoter regions was determined using methylation-specific PCR.
  
  
  RESULTS
  The experiments showed significant differences in CGBs' expression and their regulation between placental and chorionic tissues. In placental tissues and chorionic tissues from 7 to 9 weeks of gestation, the expression level of CGBs was shown to be associated with the amount of TFAP2A transcripts. It was also demonstrated that variation in the expression level of CGB genes relies on changes in methylation of CGB3-9 and CGB1-2 promoter sequences.
  
  
  CONCLUSIONS
  During pregnancy, regulation of hCG beta subunit genes expression correlates with both methylation of their promoters and TFAP2A expression level. The results suggest that these factors may be very influential in the early stages of pregnancy and may be associated with pregnancy outcome.
authors: Department of Cell Biology, Poznan University of Medical Sciences, Poznan, Poland.
authors: Aleksandra
authors: A
authors: Głodek
authors: Department of Cell Biology, Poznan University of Medical Sciences, Poznan, Poland.
authors: Marta J
authors: MJ
authors: Kubiczak
authors: Department of Cell Biology, Poznan University of Medical Sciences, Poznan, Poland.
authors: Grzegorz P
authors: GP
authors: Walkowiak
authors: Gynecologic Oncology Department, Poznan University of Medical Sciences, Poznan, Poland.
authors: Ewa
authors: E
authors: Nowak-Markwitz
authors: Department of Cell Biology, Poznan University of Medical Sciences, Poznan, Poland. Electronic address: ajanko@ump.edu.pl.
authors: Anna
authors: A
authors: Jankowska
mesh_terms: D000022:Abortion, Spontaneous / Q000235:genetics*; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000235:genetics*; D019175:DNA Methylation; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005865:Gestational Age; D006801:Humans; D010920:Placenta / Q000737:chemistry*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D050656:Transcription Factor AP-2 / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D012333:RNA, Messenger; C493673:TFAP2A protein, human; D050656:Transcription Factor AP-2
keywords: AP2α; CGB; SP1and SP3; methylation; miscarriage; placenta