title: Relationship between circulating tumor cells and epithelial to mesenchymal transition in early breast cancer.
abstract: BACKGROUND
  Circulating tumor cells (CTCs) play a crucial role in tumor dissemination and are an independent survival predictor in breast cancer (BC) patients. Epithelial to mesenchymal transition (EMT) is involved in cancer invasion and metastasis. The aim of this study was to assess correlation between CTCs and expression of EMT transcription factors TWIST1 and SLUG in breast tumor tissue.
  
  
  METHODS
  This study included 102 early BC patients treated by primary surgery. Peripheral blood mononuclear cells (PBMC) were depleted of hematopoietic cells using RossetteSep™ negative selection kit. RNA extracted from CD45-depleted PBMC was interrogated for expression of EMT (TWIST1, SNAIL1, SLUG, FOXC2 and ZEB1) and epithelial (KRT19) gene transcripts by qRT-PCR. Expression of TWIST1 and SLUG in surgical specimens was evaluated by immunohistochemistry and quantified by multiplicative score.
  
  
  RESULTS
  CTCs were detected in 24.5 % patients. CTCs exhibiting only epithelial markers were present in 8.8 % patients, whereas CTCs with only EMT markers were observed in 12.8 % of pts and CTCs co-expressing both markers were detected in 2.9 % pts. We observed lack of correlation between CTCs and expression of TWIST1 and SLUG in breast cancer cells or cancer associated stroma. Lack of correlation was observed for epithelial CTCs as well as for CTCs with EMT.
  
  
  CONCLUSIONS
  In this translational study, we showed a lack of association between CTCs and expression of EMT-inducing transcription factors, TWIST1 and SLUG, in breast tumor tissue. Despite the fact that EMT is involved in cancer invasion and metastasis our results suggest, that expression of EMT proteins in unselected tumor tissue is not surrogate marker of CTCs with either mesenchymal or epithelial features.
authors.affiliation: 2nd Department of Oncology, Faculty of Medicine, Comenius University and National Cancer Institute, Klenova 1, 833 10, Bratislava, Slovak Republic. misomego@gmail.com.|Translational Research Unit, Bratislava, Slovakia. misomego@gmail.com.|National Cancer Institute, Bratislava, Slovakia. misomego@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Mego
authors.affiliation: Department of Pathology, Bratislava, Slovakia. ciernaz@gmail.com.
authors.forename: Z
authors.initials: Z
authors.lastname: Cierna
authors.affiliation: Department of Pathology, Bratislava, Slovakia. pavol.janega@fmed.uniba.sk.|Institute of Normal and Pathological Physiology, Bratislava, Slovakia. pavol.janega@fmed.uniba.sk.
authors.forename: P
authors.initials: P
authors.lastname: Janega
authors.affiliation: National Cancer Institute, Bratislava, Slovakia. marian.karaba@nou.sk.
authors.forename: M
authors.initials: M
authors.lastname: Karaba
authors.affiliation: Institute of Molecular Biomedicine, Faculty of Medicine, Comenius University, Bratislava, Slovakia. gabriel.minarik@gmail.com.
authors.forename: G
authors.initials: G
authors.lastname: Minarik
authors.affiliation: National Cancer Institute, Bratislava, Slovakia. juraj.benca@nou.sk.
authors.forename: J
authors.initials: J
authors.lastname: Benca
authors.affiliation: Institute of Molecular Biomedicine, Faculty of Medicine, Comenius University, Bratislava, Slovakia. tatiana.sedlackova@gmail.com.
authors.forename: T
authors.initials: T
authors.lastname: Sedlácková
authors.affiliation: National Cancer Institute, Bratislava, Slovakia. gabriela.sieberova@gmail.com.
authors.forename: G
authors.initials: G
authors.lastname: Sieberova
authors.affiliation: Cancer Research Institute, Slovak Academy of Sciences, Bratislava, Slovakia. paulina.gronesova@gmail.com.
authors.forename: P
authors.initials: P
authors.lastname: Gronesova
authors.affiliation: Translational Research Unit, Bratislava, Slovakia. d.manasova@gmail.com.
authors.forename: D
authors.initials: D
authors.lastname: Manasova
authors.affiliation: National Cancer Institute, Bratislava, Slovakia. daniel.pindak@nou.sk.|Slovak Medical University, Bratislava, Slovakia. daniel.pindak@nou.sk.
authors.forename: D
authors.initials: D
authors.lastname: Pindak
authors.affiliation: 2nd Department of Oncology, Faculty of Medicine, Comenius University and National Cancer Institute, Klenova 1, 833 10, Bratislava, Slovak Republic. jozef.sufliarsky@nou.sk.|National Cancer Institute, Bratislava, Slovakia. jozef.sufliarsky@nou.sk.
authors.forename: J
authors.initials: J
authors.lastname: Sufliarsky
authors.affiliation: Department of Pathology, Bratislava, Slovakia. ludovit.danihel@fmed.uniba.sk.
authors.forename: L
authors.initials: L
authors.lastname: Danihel
authors.affiliation: Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA. jreuben@mdanderson.org.
authors.forename: J M
authors.initials: JM
authors.lastname: Reuben
authors.affiliation: 2nd Department of Oncology, Faculty of Medicine, Comenius University and National Cancer Institute, Klenova 1, 833 10, Bratislava, Slovak Republic. jozef.mardiak@nou.sk.|National Cancer Institute, Bratislava, Slovakia. jozef.mardiak@nou.sk.
authors.forename: J
authors.initials: J
authors.lastname: Mardiak
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology* / Q000601:surgery*; D045744:Cell Line, Tumor; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D045325:HCT116 Cells; D006367:HeLa Cells; D006801:Humans; D061986:MCF-7 Cells; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D051879:Twist-Related Protein 1 / Q000235:genetics* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D009687:Nuclear Proteins; C000604407:SNAI1 protein, human; D000071250:Snail Family Transcription Factors; C103173:TWIST1 protein, human; D014157:Transcription Factors; D051879:Twist-Related Protein 1