title: Analysis of differentially expressed proteins in oral squamous cell carcinoma by MALDI-TOF MS.
abstract: OBJECTIVE
  To explore the presence of differentially expressed proteins in OSCC for discrimination of tumour and normal mucosa to establish potential biomarkers and therapeutic targets.
  
  
  METHODS
  Paired protein samples of 12 individuals (tongue cancer and non-cancerous mucosa) were separated by two-dimensional polyacrylamid gel electrophoresis. The protein patterns were compared pairwise and protein spots were quantified. We identified about 70 regulated proteins which we subsequently identified by MALDI-TOF mass spectrometry.
  
  
  RESULTS
  Cancerous and non-cancerous tissues could be most precisely distinguished by a panel of proteins. They include the heat shock proteins (hsp)70 and 90, keratins (ck) 5, 6, 13, 14, 16, 17 and 19, beta globin, alpha-2-actin, stratifin, tropomyosin, calreticulin precursor, beta-2-tubulin, galectin7, thioredoxin, involucrin, adenylyl-cyclase-associated protein, disulfide isomerase-associated protein, thyrosine 3-monooxygenase, MYL2 and the s100 calcium binding protein. MYL3, cardiac muscle alpha actin 1 proprotein and transferrin were under-represented in OSCC. Six biomarkers, ck6 und ck13, beta globin, alpha-2-actin, hsp70 and hsp90 discriminated best between cancerous and non-cancerous oral tissues. All over-expressed proteins were analysed by STRING-analysis to highlight experimentally determined and computationally predicted interactions between the proteins. Especially involucrin, hsp70, calreticulin precursor, stratifin, (ck) 5, 6, 14, 19, tyrosine 3-monooxygenase, beta-2-tubulin and disulfide isomerase associated protein showed multiple relations.
  
  
  CONCLUSIONS
  We identified six proteins which are differentially expressed in most OSCC compared to healthy tissues. Of those, by string analysis, multiple interaction partners are assumed for hsp70. This protein is supposed to be the most promising candidate as marker molecule and target for OSCC therapy.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Centre of the Johannes Gutenberg University Mainz, Germany. uta.thiel@unimedizin-mainz.de
authors.forename: Uta J E
authors.initials: UJ
authors.lastname: Thiel
authors.forename: Ralph
authors.initials: R
authors.lastname: Feltens
authors.forename: Boris
authors.initials: B
authors.lastname: Adryan
authors.forename: Rita
authors.initials: R
authors.lastname: Gieringer
authors.forename: Christoph
authors.initials: C
authors.lastname: Brochhausen
authors.forename: Robert
authors.initials: R
authors.lastname: Schuon
authors.forename: Thomas
authors.initials: T
authors.lastname: Fillies
authors.forename: Franz
authors.initials: F
authors.lastname: Grus
authors.forename: Wolf J
authors.initials: WJ
authors.lastname: Mann
authors.forename: Juergen
authors.initials: J
authors.lastname: Brieger
mesh_terms: D000199:Actins / Q000032:analysis / Q000096:biosynthesis; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D016022:Case-Control Studies; D019295:Computational Biology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D018840:HSP70 Heat-Shock Proteins / Q000032:analysis / Q000096:biosynthesis; D018841:HSP90 Heat-Shock Proteins / Q000032:analysis / Q000096:biosynthesis; D006801:Humans; D007525:Isoelectric Focusing; D053535:Keratin-13 / Q000032:analysis / Q000096:biosynthesis; D053553:Keratin-6 / Q000032:analysis / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000737:chemistry / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000032:analysis / Q000096:biosynthesis*; D020543:Proteome; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014062:Tongue Neoplasms / Q000378:metabolism*; D055544:beta-Globins / Q000032:analysis / Q000096:biosynthesis
chemical_list: D000199:Actins; D014408:Biomarkers, Tumor; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D053535:Keratin-13; D053553:Keratin-6; D009363:Neoplasm Proteins; D020543:Proteome; D055544:beta-Globins