title: Radiotherapy response in oral squamous carcinoma cell lines: evaluation of apoptotic proteins as prognostic factors.
abstract: BACKGROUND
  In this study, we investigated the importance of apoptosis for cell death after radiotherapy, and whether the expression of pro- and anti-apoptotic proteins has any correlation to the radiosensitivity.
  
  
  METHODS
  Three oral squamous cell carcinoma cell lines, UT-SCC-2, UT-SCC-9 and UT-SCC-24A, were subjected to radiotherapy. After irradiation, viable and dead cells were counted to determine radiation sensitivity and apoptosis was analyzed by measurement of caspase-3 activity. The expressions of pro- and anti-apoptotic proteins were assessed using western blot analyses.
  
  
  CONCLUSIONS
  After irradiation, apoptotic morphology and caspase-3 activity were only detected in cell lines exhibiting high or moderate radiosensitivity. Western blot analysis indicates that survivin, epidermal growth factor receptor, cyclooxygenase-2, and Bcl-x(L) are critical components in irradiation resistance of the investigated cell lines. Moreover, our results suggest that apoptotic cell death and the balance between pro- and anti-apoptotic proteins are of importance for the outcome of radiotherapy.
authors.affiliation: Division of Otorhinolaryngology, University Hospital, SE-58185 Linköping, Sweden. karin.roberg@inr.liu.se
authors.forename: Karin
authors.initials: K
authors.lastname: Roberg
authors.forename: Ann-Charlotte
authors.initials: AC
authors.lastname: Jonsson
authors.forename: Reidar
authors.initials: R
authors.lastname: Grénman
authors.forename: Lena
authors.initials: L
authors.lastname: Norberg-Spaak
mesh_terms: D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000032:analysis; D002294:Carcinoma, Squamous Cell / Q000737:chemistry / Q000473:pathology / Q000532:radiotherapy*; D053148:Caspase 3 / Q000032:analysis; D045744:Cell Line, Tumor / Q000528:radiation effects*; D051546:Cyclooxygenase 2 / Q000032:analysis; D066246:ErbB Receptors / Q000032:analysis; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins / Q000032:analysis; D009062:Mouth Neoplasms / Q000737:chemistry / Q000473:pathology / Q000532:radiotherapy*; D009363:Neoplasm Proteins / Q000032:analysis; D011379:Prognosis; D011836:Radiation Tolerance; D000077022:Survivin; D051028:bcl-2-Associated X Protein / Q000032:analysis; D051020:bcl-X Protein / Q000032:analysis
chemical_list: C107489:BIRC5 protein, human; D014408:Biomarkers, Tumor; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D000077022:Survivin; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; D051546:Cyclooxygenase 2; D066246:ErbB Receptors; D053148:Caspase 3