title: Embryonic stem cells markers Oct4 and Nanog correlate with perineural invasion in human salivary gland mucoepidermoid carcinoma.
abstract: BACKGROUND
  Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy and is successfully treated by surgery and radiation. However, some patients have recurrent tumours and in these cases, few treatments options are available. Cancer stem cells (CSC) have been observed and isolated from different solid tumours based on the expression of stem cell markers. These cells are associated with tumour initiation, progression as well as treatment resistance. In this study, the expression of stem cell markers CD44, Bmi1, Oct4 and Nanog was evaluated in non-neoplastic salivary tissue and in MEC.
  
  
  METHODS
  Twenty-eight samples of MEC and their corresponding non-neoplastic salivary tissue were examined by immunohistochemistry and the stem cell markers expression was correlated with histological and clinical parameters.
  
  
  RESULTS
  CD44 was expressed in the membrane of serous and mucous acini as well as in the ductal cells in normal gland tissue. Bmi1, Oct4 and Nanog were mainly expressed in ductal structures. In MEC, CD44 and Bmi1 showed strong expression in all types of neoplastic cells and both markers revealed intense expression in tumour invasive front. Oct4 and Nanog protein expression was associated with desmoplasia and perineural invasion. Only Oct4 positive tumours were associated with dissociative growth pattern and committed margins.
  
  
  CONCLUSIONS
  The stem cell markers CD44, Bmi1, Oct4 and Nanog are frequently expressed in MEC in relation to normal salivary gland and Oct4 and Nanog expression may contribute to aggressiveness and worst prognosis in MEC patients.
authors.affiliation: Department of Oral Pathology, School of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Maria Fernanda Setúbal
authors.initials: MF
authors.lastname: Destro Rodrigues
authors.affiliation: Department of Oral Pathology, School of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Bruno Tavares
authors.initials: BT
authors.lastname: Sedassari
authors.affiliation: Department of Oral Pathology, School of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Carina Magalhães
authors.initials: CM
authors.lastname: Esteves
authors.affiliation: Department of Oral Pathology, School of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Nathália Paiva
authors.initials: NP
authors.lastname: de Andrade
authors.affiliation: Department of Pathology, School of Medicine, State University of Campinas, Campinas, Brazil.
authors.forename: Albina
authors.initials: A
authors.lastname: Altemani
authors.affiliation: Department of Oral Pathology, School of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Suzana Cantanhede Orsini Machado
authors.initials: SC
authors.lastname: de Sousa
authors.affiliation: Department of Oral Pathology, School of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Fabio Daumas
authors.initials: FD
authors.lastname: Nunes
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D018277:Carcinoma, Mucoepidermoid / Q000378:metabolism* / Q000473:pathology; D002648:Child; D005260:Female; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D000071317:Nanog Homeobox Protein / Q000378:metabolism*; D009361:Neoplasm Invasiveness / Q000503:physiopathology; D014411:Neoplastic Stem Cells; D050814:Octamer Transcription Factor-3 / Q000378:metabolism*; D063150:Polycomb Repressive Complex 1 / Q000378:metabolism; D012468:Salivary Gland Neoplasms / Q000378:metabolism* / Q000473:pathology; D055815:Young Adult
chemical_list: C069077:BMI1 protein, human; D014408:Biomarkers, Tumor; C497483:CD44 protein, human; D018960:Hyaluronan Receptors; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; D063150:Polycomb Repressive Complex 1
keywords: histopathological features; mucoepidermoid carcinoma; salivary gland; stem cell markers