title: Saliva as a biomarker for head and neck squamous cell carcinoma: in vitro detection of cytotoxic effects by using the plating efficiency index.
abstract: Worldwide, the incidence of head and neck squamous cell carcinoma (HNSCC) is increasing. The development of an effective prevention program would provide a promising opportunity to control this disease. We applied the 'plating efficiency index' of Chinese hamster lung fibroblasts to demonstrate the presence of cytotoxic effects in saliva samples from cancer patients as well as from healthy probands. Correlations between individual risk factors and the cytotoxic effects of saliva specimens were analysed and evaluated. Saliva samples were obtained from male patients (n=43) with carcinomas of the upper aerodigestive tract, and from a healthy age-matched male control group (n=131) with different tobacco and alcohol consumption habits. The extraction of non-stimulated sober saliva was chosen for this investigation. In vitro cytotoxicity of the saliva was detected using the permanent mammalian cell line V79 (lung fibroblasts) of Chinese hamsters. The determination of the plating efficiency index was made in the logarithmic growth phase of the initial cell culture. A reduction in cell colonies (plating efficiency) of at least 50% was defined as strongly cytotoxic. A significant direct correlation was found between daily tobacco consumption and the reduction of plating efficiency (p<0.0001). We found only a moderate increase in the cytotoxicity of tested saliva samples in correlation with daily alcohol uptake. The difference between tumor patients and healthy probands was highly significant (chi(2) test; p=0.001). Using the method of logistic regression analysis, we found a 3.6-fold increased cancer risk in probands with cytotoxic saliva (p<0.001). According to our results, the plating efficiency index seems to be a suitable method for the detection of increased cancer risk. In combination with several effective biomarkers on cytogenetic end-points, it may help to establish biomonitoring programs for secondary cancer prevention.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, University of Homburg/Saar, 66421 Homburg/Saar, Germany. hnomblo@uks.eu
authors.forename: Marc B
authors.initials: MB
authors.lastname: Bloching
authors.forename: James
authors.initials: J
authors.lastname: Barnes
authors.forename: Wolfram
authors.initials: W
authors.lastname: Aust
authors.forename: Stephan
authors.initials: S
authors.lastname: Knipping
authors.forename: Katrin
authors.initials: K
authors.lastname: Neumann
authors.forename: Tamara
authors.initials: T
authors.lastname: Grummt
authors.forename: Ramin
authors.initials: R
authors.lastname: Naim
mesh_terms: D000328:Adult; D015415:Biomarkers; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000473:pathology*; D002455:Cell Division; D002470:Cell Survival; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012463:Saliva / Q000166:cytology / Q000502:physiology*; D012907:Smoking
chemical_list: D015415:Biomarkers