title: Expression of proliferative markers in ameloblastomas and malignant odontogenic tumors.
abstract: OBJECTIVE
  To compare the proliferative activity in ameloblastoma and malignant odontogenic tumors, as assessed by Ki-67 immunostaining and determine whether expression of substance P (SP) and NK-1 receptor (NK-1R) is related to cell proliferation in these tumors.
  
  
  METHODS
  Immunohistochemistry was used to evaluate protein expression in 44 benign and malignant odontogenic tumors from 39 patients. Immunohistochemistry was performed with anti-SP, anti-NK-1R, and anti-Ki-67 monoclonal antibodies, and the clinical and pathological data of the patients with odontogenic tumor were evaluated.
  
  
  RESULTS
  Expression of Ki-67 in malignant odontogenic tumors was significantly higher than in ameloblastomas (P < 0.001), and the expression level was associated with higher expression of NK-1R. Among the ameloblastomas, there was significantly higher expression of Ki-67 in peripheral ameloblastic-like cells (3.3 ± 4.1) than in stellate reticulum-like cells (2.6 ± 3.7) (P = 0.04). In the majority of tissue locations of the malignant tumors, expression of SP and NK-1R was positively correlated with higher expression of Ki-67.
  
  
  CONCLUSIONS
  These findings show that the expression level of Ki-67 in ameloblastomas was positively correlated with the rate of growth of odontogenic tumors. Overexpression of NK-1R complex in malignant odontogenic tumors could be part of the trigger stimulus that results in higher proliferative activity of the tumor.
authors.affiliation: Pathology Graduate Program, Fluminense Federal University (UFF), Niterói, Brazil.
authors.forename: D
authors.initials: D
authors.lastname: Otero
authors.forename: S Q C
authors.initials: SQ
authors.lastname: Lourenço
authors.forename: I
authors.initials: I
authors.lastname: Ruiz-Ávila
authors.forename: M
authors.initials: M
authors.lastname: Bravo
authors.forename: T
authors.initials: T
authors.lastname: Sousa
authors.forename: P A S
authors.initials: PA
authors.lastname: de Faria
authors.forename: M A
authors.initials: MA
authors.lastname: González-Moles
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000564:Ameloblastoma / Q000378:metabolism* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000378:metabolism*; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000378:metabolism; D002648:Child; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D008339:Mandibular Neoplasms / Q000378:metabolism* / Q000473:pathology; D008441:Maxillary Neoplasms / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000378:metabolism; D009808:Odontogenic Tumors / Q000378:metabolism* / Q000473:pathology; D018040:Receptors, Neurokinin-1 / Q000378:metabolism; D013373:Substance P / Q000378:metabolism; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D018040:Receptors, Neurokinin-1; D013373:Substance P