title: Proteins and peptides in parotid saliva of irradiated patients compared to that of healthy controls using SELDI-TOF-MS.
abstract: BACKGROUND
  Radiotherapy to the head and neck area damages the salivary glands. As a consequence hyposalivation may occur, but also the protein composition of saliva may be affected possibly compromising oral health. The aim of our study was to compare the relative abundance of proteins and peptides in parotid saliva of irradiated patients to that of healthy controls.
  
  
  METHODS
  Using Lashley cups and citric acid, saliva from the parotid glands was collected from nine irradiated patients and ten healthy controls. The samples were analyzed with SELDI-TOF-MS using a NP20 and IMAC-30 chip in the molecular weight range of 1-30 kDa.
  
  
  RESULTS
  On the NP20 chip 61 (out of 217) and on the IMAC-30 chip 32 (out of 218) peaks differed significantly in intensity between the saliva of the irradiated patients and healthy controls. 55 % of the significant peaks showed higher intensity and 45 % showed lower intensity in the saliva of irradiated patients. The peaks may represent, amongst others, the salivary proteins lysozyme, histatins, cystatin, protein S100 and PRP's.
  
  
  CONCLUSIONS
  Large differences were found in the relative abundance of a wide range of proteins and peptides in the parotid saliva of irradiated patients compared to healthy controls.
authors.affiliation: Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and VU University Amsterdam, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands. a.laheij@acta.nl.
authors.forename: Alexa M G A
authors.initials: AM
authors.lastname: Laheij
authors.affiliation: Department of Radiation Oncology, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands. c.r.rasch@amc.uva.nl.
authors.forename: Coen N
authors.initials: CN
authors.lastname: Rasch
authors.affiliation: Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and VU University Amsterdam, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands. b.brandt@acta.nl.
authors.forename: Bernd W
authors.initials: BW
authors.lastname: Brandt
authors.affiliation: Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and VU University Amsterdam, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands. j.d.soet@acta.nl.
authors.forename: Johannes J
authors.initials: JJ
authors.lastname: de Soet
authors.affiliation: Top Institute Food and Nutrition, PO Box 557, 6700 AN, Wageningen, The Netherlands. rayskip@hotmail.com.
authors.forename: Raymond G
authors.initials: RG
authors.lastname: Schipper
authors.affiliation: Central Laboratory for Haematology, Radboud University Nijmegen Medical Centre Post 476, PO Box 9101, 6500 HB, Nijmegen, The Netherlands. a.loof@labgk.umcn.nl.
authors.forename: Arnoud
authors.initials: A
authors.lastname: Loof
authors.affiliation: NIZO Food Research B.V., P.O. Box 20, 6710 BA, Ede, The Netherlands. erika.silletti@nizo.com.
authors.forename: Erika
authors.initials: E
authors.lastname: Silletti
authors.affiliation: Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and VU University Amsterdam, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands. c.v.loveren@acta.nl.
authors.forename: Cor
authors.initials: C
authors.lastname: van Loveren
mesh_terms: D000328:Adult; D000368:Aged; D015891:Cystatins / Q000032:analysis; D005260:Female; D054808:Histatins / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D009113:Muramidase / Q000032:analysis; D010306:Parotid Gland / Q000378:metabolism / Q000528:radiation effects*; D010455:Peptides / Q000032:analysis*; D040901:Proteomics / Q000379:methods; D011878:Radiotherapy / Q000379:methods*; D009418:S100 Proteins / Q000032:analysis; D012463:Saliva / Q000378:metabolism*; D012471:Salivary Proteins and Peptides / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D015891:Cystatins; D054808:Histatins; D010455:Peptides; D009418:S100 Proteins; D012471:Salivary Proteins and Peptides; D009113:Muramidase