title: Immunoexpression of growth factors and receptors in polymorphous low-grade adenocarcinoma.
abstract: BACKGROUND
  Polymorphous low-grade adenocarcinoma (PLGA) is a rare malignant tumor that usually arises in the minor salivary glands. Growth factors are cell-secreted peptides that regulate biological processes such as growth, proliferation, and differentiation. In salivary gland tumors, immunoexpression of growth factors and their receptors is associated with cell proliferation, malignant transformation, and tumor invasion. This study analyzed the expression of growth factors and receptors in PLGA, in other to better understand the mechanisms involved in the process of neoplastic cell proliferation and tumor progression.
  
  
  METHODS
  The expression of growth factors FGF-2, PDGF-A, PDGF-B and receptors FGFR-1, FGFR-2, PDGFR-α, and EGFR was analyzed in 24 PLGA samples in comparison with normal salivary glands, by immunohistochemistry. A semi-quantitative analysis determined cell positivity in all stained sections. Scores were assigned according to percentage of reactive cells: score 0 < 10%; score 1-10 to 25%; score 2-25% to 50%; score 3->50%. The level of significance was set at 5%.
  
  
  RESULTS
  Most of the growth factors and receptors, apart from FGFR-2, were significantly reactive in PLGA. Comparing to salivary acini, all of the reactive growth factors and receptors were significantly stronger in PLGA. Comparing to salivary ducts, the expression of FGF-2, PDGF-B, FGFR-1, and EGFR was significantly stronger in the nuclei and/or cytoplasm of the neoplastic cells.
  
  
  CONCLUSIONS
  The increased expression of the growth factors and receptors in the PLGA, compared to normal salivary glands, may be related to cell proliferation, somehow participating in the oncogenic process.
authors.affiliation: Department of Oral Pathology, Lutheran University of Palmas, Tocantins, Brazil.|Department of Health Sciences, Federal University of Tocantins, Palmas, Tocantins, Brazil.
authors.forename: Ana Cláudia Garcia
authors.initials: AC
authors.lastname: Rosa
authors.affiliation: Department of Oral Pathology, São Leopoldo Mandic Institute and Research Center, Campinas, São Paulo, Brazil.
authors.forename: Andresa Borges
authors.initials: AB
authors.lastname: Soares
authors.affiliation: Department of Oral Pathology, São Leopoldo Mandic Institute and Research Center, Campinas, São Paulo, Brazil.
authors.forename: Fabrício Passador
authors.initials: FP
authors.lastname: Santos
authors.affiliation: Department of Oral Pathology, São Paulo State University, Araçatuba, São Paulo, Brazil.
authors.forename: Cristiane
authors.initials: C
authors.lastname: Furuse
authors.affiliation: Department of Oral Pathology, São Leopoldo Mandic Institute and Research Center, Campinas, São Paulo, Brazil.
authors.forename: Vera Cavalcanti
authors.initials: VC
authors.lastname: de Araújo
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation / Q000502:physiology; D002467:Cell Nucleus / Q000473:pathology; D049109:Cell Proliferation / Q000502:physiology; D002471:Cell Transformation, Neoplastic / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis*; D017978:Receptors, Growth Factor / Q000096:biosynthesis*; D012468:Salivary Gland Neoplasms / Q000378:metabolism* / Q000473:pathology; D012470:Salivary Glands, Minor / Q000378:metabolism* / Q000473:pathology
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D017978:Receptors, Growth Factor
keywords: EGFR; FGF; PDGF; Polymorphous low-grade adenocarcinoma; growth factors; salivary glands