title: A proteomic approach to compare saliva from individuals with and without oral leukoplakia.
abstract: Oral leukoplakia is the most common potentially malignant disorder in the oral cavity and can precede carcinoma. This study aimed to identify possible oral leukoplakia salivary biomarkers.
  
  
  
  Unstimulated saliva was collected from participants and protein concentration was determined. Proteins were then precipitated with cold acetone and separated using 2DE over a pH range of 3-10. Spot demarcation and matching were performed and protein identification was done through MS analysis. Oral leukoplakia tissues were submitted to immunohistochemistry analysis for keratin 10 (CK10). A complementary analysis of oral leukoplakias that were not included previously was performed in addition.
  
  
  
  226±10 spots were identified in oral leukoplakia 2DE gels, and 262±12 spots were identified in volunteers. Twenty-two spots were highly abundant in oral leukoplakias or not detected in the control group, such as apolipoprotein A1, alpha amylase, cystatins, keratin 10, and lysozyme precursor. All were identified. All oral leukoplakia cases were immunopositive for CK10, mainly in the superficial epithelial layers.
  
  
  
  The 2DE salivary protein profiles of individuals with and without oral leukoplakia were observably different. CK10 appears to be an interesting protein and should be further studied in oral carcinogenesis.
  
  
  
  MS-based proteomics enables large-scale analysis of proteins. Proteomics can provide detailed descriptions of proteomes of cells and tissues, including body fluids, and appears as a powerful tool to study human disorders. Saliva is readily accessible through non invasive collection and can mirror diverse disease states. Saliva from both diseased and healthy subjects can be analyzed through 2DE and differences between groups could be found. Routine immunohistochemistry analysis confirmed one of these findings, with CK10 being positive tissues from individuals with oral leukoplakia. Therefore, the present study allows insights into development of an important potential oral cancer precursor, named oral leukoplakia. However, the results can be extrapolated and tested in other precancer states, such as proliferative verrucous leukoplakia, patients at risk of oral cancer due to lifestyle behavior and/or cancer history in the family or even those who are under surveillance after a treated primary oral cancer.
authors.affiliation: Oral Pathology, Federal Fluminense University (UFF), R. Marques de Paraná, 303/4° andar (Hospital Universitário Antônio Pedro), Centro Niterói, Brazil, CEP: 24033-900. Electronic address: daniellecamisasca@yahoo.com.br.
authors.forename: Danielle Resende
authors.initials: DR
authors.lastname: Camisasca
authors.affiliation: Serviço de Hematologia, Laboratório de Genética Aplicada, Brazilian National Cancer Institute (INCA), Hospital do Câncer I, Praça da Cruz Vermelha, 23 - 6° andar, Rio de Janeiro, RJ, Brazil, CEP: 20230-130. Electronic address: lorena.da@terra.com.br.
authors.forename: Lorena
authors.initials: L
authors.lastname: da Rós Gonçalves
authors.affiliation: Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro (UFRJ), Av. Athos daSilveira, 149/541, Cidade Universitária, Rio deJaneiro, RJ, Brazil, CEP: 21941-909. Electronic address: marcia@iq.ufrj.br.
authors.forename: Márcia Regina
authors.initials: MR
authors.lastname: Soares
authors.affiliation: Serviço de Hematologia, Laboratório de Genética Aplicada, Brazilian National Cancer Institute (INCA), Hospital do Câncer I, Praça da Cruz Vermelha, 23 - 6° andar, Rio de Janeiro, RJ, Brazil, CEP: 20230-130; Laboratório de Hemostase e Venenos e Unidade de Espectrometria de Massas e Proteômica, Instituto de Bioquímica Médica, Programa de Biologia Estrutural, Universidade Federal do Rio de Janeiro (UFRJ), Av. Carlos Chagas Filho, 373, CCS Bloco H2 sala 04, Cidade Universitária, Rio de Janeiro, RJ, Brazil, CEP 21941-902. Electronic address: nessasandim@gmail.com.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Sandim
authors.affiliation: Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro (UFRJ), Av. Athos daSilveira, 149/541, Cidade Universitária, Rio deJaneiro, RJ, Brazil, CEP: 21941-909. Electronic address: fabiocsn@gmail.com.
authors.forename: Fábio César Sousa
authors.initials: FC
authors.lastname: Nogueira
authors.affiliation: Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro (UFRJ), Av. Athos daSilveira, 149/541, Cidade Universitária, Rio deJaneiro, RJ, Brazil, CEP: 21941-909. Electronic address: scarlogarcia@gmail.com.
authors.forename: Carlos Henrique Saraiva
authors.initials: CH
authors.lastname: Garcia
authors.affiliation: Serviço de Hematologia, Laboratório de Genética Aplicada, Brazilian National Cancer Institute (INCA), Hospital do Câncer I, Praça da Cruz Vermelha, 23 - 6° andar, Rio de Janeiro, RJ, Brazil, CEP: 20230-130. Electronic address: chokus05@hotmail.com.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Santana
authors.affiliation: Odontoclínica Central do Exército (OCEX), Praça da República, 123 - Centro, Rio de Janeiro, RJ, Brazil, CEP: 20211-340. Electronic address: silviaoliv@hotmail.com.
authors.forename: Silvia Paula
authors.initials: SP
authors.lastname: de Oliveira
authors.affiliation: Oncology Graduate Program, Molecular Carcinogenesis Program, Research Center, Brazilian National Cancer Institute, Rua André Cavalcanti, 37, 6° andar, Centro, 20231-050 Rio de Janeiro, RJ, Brazil. Electronic address: labuexm@hotmail.com.
authors.forename: Luisa Aguirre
authors.initials: LA
authors.lastname: Buexm
authors.affiliation: Pathology Division (Divisão de Patologia), Brazilian National Cancer Institute (INCA), Rua Cordeiro da Graça, 156, Rio de Janeiro, RJ, Brazil, CEP:20220-400. Electronic address: pauloafaria@gmail.com.
authors.forename: Paulo Antônio Silvestre
authors.initials: PA
authors.lastname: de Faria
authors.affiliation: Head and Neck Surgery Department, Brazilian National Cancer Institute (INCA), Hospital do Câncer I, Praça da Cruz Vermelha, 23 - 6°andar, Rio de Janeiro, RJ, Brazil, CEP:20230-130. Electronic address: fdias@inca.gov.br.
authors.forename: Fernando Luiz
authors.initials: FL
authors.lastname: Dias
authors.affiliation: Serviço de Hematologia, Laboratório de Genética Aplicada, Brazilian National Cancer Institute (INCA), Hospital do Câncer I, Praça da Cruz Vermelha, 23 - 6° andar, Rio de Janeiro, RJ, Brazil, CEP: 20230-130. Electronic address: deniseap@inca.gov.br.
authors.forename: Denise de Abreu
authors.initials: DA
authors.lastname: Pereira
authors.affiliation: Rede Proteômica do Rio de Janeiro, Rio de Janeiro, Brazil; Laboratório de Hemostase e Venenos e Unidade de Espectrometria de Massas e Proteômica, Instituto de Bioquímica Médica, Programa de Biologia Estrutural, Universidade Federal do Rio de Janeiro (UFRJ), Av. Carlos Chagas Filho, 373, CCS Bloco H2 sala 04, Cidade Universitária, Rio de Janeiro, RJ, Brazil, CEP 21941-902. Electronic address: lzingali@bioqmed.ufrj.br.
authors.forename: Russolina B
authors.initials: RB
authors.lastname: Zingali
authors.affiliation: Serviço de Hematologia, Laboratório de Genética Aplicada, Brazilian National Cancer Institute (INCA), Hospital do Câncer I, Praça da Cruz Vermelha, 23 - 6° andar, Rio de Janeiro, RJ, Brazil, CEP: 20230-130. Electronic address: galvesbrown@gmail.com.
authors.forename: Gilda
authors.initials: G
authors.lastname: Alves
authors.affiliation: Oral Pathology, Federal Fluminense University (UFF), R. Marques de Paraná, 303/4° andar (Hospital Universitário Antônio Pedro), Centro Niterói, Brazil, CEP: 24033-900. Electronic address: silourenco2015@gmail.com.
authors.forename: Simone Queiroz Chaves
authors.initials: SQ
authors.lastname: Lourenço
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor; D016022:Case-Control Studies; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D053550:Keratin-10 / Q000032:analysis / Q000302:isolation & purification; D007972:Leukoplakia, Oral / Q000737:chemistry*; D008875:Middle Aged; D011230:Precancerous Conditions / Q000175:diagnosis; D020543:Proteome / Q000032:analysis; D040901:Proteomics / Q000379:methods*; D012463:Saliva / Q000737:chemistry*
chemical_list: D014408:Biomarkers, Tumor; C507493:KRT10 protein, human; D020543:Proteome; D053550:Keratin-10
keywords: 2D gel electrophoresis; Keratin-10; MALDI-MS; Oral leukoplakia; Saliva