title: miR-142-3p as a biomarker of blastocyst implantation failure - A pilot study.
abstract: OBJECTIVE
  This study aims to find whether microRNAs (miRNAs) detected in the culture medium of embryos produced in vitro could be potential biomarkers of embryo implantation.
  
  
  METHODS
  Culture media samples from 36 embryos, derived from patients undergoing intracytoplasmic sperm injection (ICSI) in a private university-affiliated IVF center, were collected between January/2015 and November/2015. Samples were collected on day three and embryo transfers were performed on day five and all embryos reached the blastocyst stage. Samples were split into groups according to the embryo implantation result: Positive-Implantation-Group (n=18) or Negative-Implantation-Group (n=18). For the first analysis, samples were pooled in three sets for each group (6-7 spent media per pool). MicroRNAs were extracted from spent media and cDNA was synthesized. C. elegans miR-39 was used as RNA spike-in to normalize the gene expression analysis. The expression of microRNAs into the spent media from the Positive-Implantation-Group was compared with those from the Negative-Implantation-Group. A set of seven miRNAs (miR-21, miR-142-3p, miR-19b, miR-92a, miR-20b, miR-125a and miR148a) selected according with the literature, was tested. To check whether miRNAs could be detected in individual samples of culture media, in a second analysis, ten more samples were tested for miR-21 and miR-142-3p.
  
  
  RESULTS
  From the sevens tested miRNAs, a significant increased expression of miR-142-3p could be noted in the Negative-Implantation-Group (P<0.001). For other three miRNAs (miR-21, miR-19b and miR-92a) a difference in expression was observed, however it did not reach a statistical significance. In addition, when ten non-redundant samples were tested to check if miRNAs could be detected in individual samples of culture media, the highly specific amplification of mature miRNAs, including miR-142-3p, could be noted.
  
  
  CONCLUSIONS
  Our findings suggest that miR-142-3p, previously described as a tumor suppressor and cell cycle inhibitor, may be a potential biomarker of blastocyst implantation failure. The identification of miRNAs on individual culture medium samples offers unique opportunities for non-invasive early diagnosis of blastocyst implantation.
authors.affiliation: Fertility Medical Group - São Paulo/SP - Brazil.|Instituto Sapientiae - Centro de Estudos e Pesquisa em Reprodução Assistida - São Paulo/SP - Brazil.
authors.forename: Edson
authors.initials: E
authors.lastname: Borges
authors.affiliation: Fertility Medical Group - São Paulo/SP - Brazil.|Instituto Sapientiae - Centro de Estudos e Pesquisa em Reprodução Assistida - São Paulo/SP - Brazil.
authors.forename: Amanda Souza
authors.initials: AS
authors.lastname: Setti
authors.affiliation: Fertility Medical Group - São Paulo/SP - Brazil.|Instituto Sapientiae - Centro de Estudos e Pesquisa em Reprodução Assistida - São Paulo/SP - Brazil.|Disciplina de Urologia, Área de Reprodução Humana, Departamento de Cirurgia, Universidade Federal de São Paulo/SP - Brazil.
authors.forename: Daniela P A F
authors.initials: DP
authors.lastname: Braga
authors.affiliation: Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas UNICAMP/SP - Brazil.
authors.forename: Murilo V
authors.initials: MV
authors.lastname: Geraldo
authors.affiliation: Fertility Medical Group - São Paulo/SP - Brazil.
authors.forename: Rita de Cássia S
authors.initials: RC
authors.lastname: Figueira
authors.affiliation: Fertility Medical Group - São Paulo/SP - Brazil.|Instituto Sapientiae - Centro de Estudos e Pesquisa em Reprodução Assistida - São Paulo/SP - Brazil.
authors.forename: Assumpto
authors.initials: A
authors.lastname: Iaconelli
keywords: Blastocyst; ICSI; MicroRNA; culture medium; implantation