title: OCT-4 expression in follicular and luteal phase endometrium: a pilot study.
abstract: BACKGROUND
  The stem cell marker Octamer-4 (OCT-4) is expressed in human endometrium. Menstrual cycle-dependency of OCT-4 expression has not been investigated to date.
  
  
  METHODS
  In a prospective, single center cohort study of 98 women undergoing hysteroscopy during the follicular (n = 49) and the luteal (n = 40) phases of the menstrual cycle, we obtained endometrial samples. Specimens were investigated for OCT-4 expression on the mRNA and protein levels using reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. Expression of OCT-4 was correlated to menstrual cycle phase.
  
  
  RESULTS
  Of 89 women sampled, 49 were in the follicular phase and 40 were in the luteal phase. OCT-4 mRNA was detected in all samples. Increased OCT-4 mRNA levels in the follicular and luteal phases was found in 35/49 (71%) and 27/40 (68%) of women, respectively (p = 0.9). Increased expression of OCT-4 protein was identified in 56/89 (63%) samples. Increased expression of OCT-4 protein in the follicular and luteal phases was found in 33/49 (67%) and 23/40 (58%) of women, respectively (p = 0.5).
  
  
  CONCLUSIONS
  On the mRNA and protein levels, OCT-4 is not differentially expressed during the menstrual cycle. Endometrial OCT-4 is not involved in or modulated by hormone-induced cyclical changes of the endometrium.
authors.affiliation: Department of Obstetrics and Gynecology, Medical University of Vienna, Vienna, Austria.
authors.forename: Eva-Katrin
authors.initials: EK
authors.lastname: Bentz
authors.forename: Marina
authors.initials: M
authors.lastname: Kenning
authors.forename: Christian
authors.initials: C
authors.lastname: Schneeberger
authors.forename: Andrea
authors.initials: A
authors.lastname: Kolbus
authors.forename: Johannes C
authors.initials: JC
authors.lastname: Huber
authors.forename: Lukas A
authors.initials: LA
authors.lastname: Hefler
authors.forename: Clemens B
authors.initials: CB
authors.lastname: Tempfer
mesh_terms: D000328:Adult; D053687:Adult Stem Cells / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism*; D015331:Cohort Studies; D004717:Endometrium / Q000166:cytology / Q000378:metabolism*; D005260:Female; D005498:Follicular Phase / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D015907:Hysteroscopy; D007150:Immunohistochemistry; D008183:Luteal Phase / Q000378:metabolism*; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism*; D010865:Pilot Projects; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D015415:Biomarkers; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; D012333:RNA, Messenger