title: Cigarette smoke-induced effects on the cell cycle in oral cancer cells: reduction of G2/M fraction.
abstract: BACKGROUND
  Cigarette smoke (CS) is the main inducer of oral cancer, increasing its prevalence by 4-7 times.
  
  
  METHODS
  We examined the suitability of cell models SCC-25 and SCC-15 for studying effects of CS on oral cancer cells and whether CS significantly affects the cell cycle using fluorescence-activated cell sorting assays.
  
  
  RESULTS
  There was significant change in the fraction of SCC-15 cells in pre-G1 state following CS exposure. At 60 and 90 min, increase in the pre-G1 cell fraction was 118% (p<0.05) and 135% (p<0.01) respectively. The G2/M cell fraction was significantly lower following CS exposure. At 90 and 120 min following CS exposure, the G2/M fraction levels had declined by 44% (p<0.05) and 34% (p<0.01) respectively. Results for SCC-25 cells were similar. At 90 and 120 min following CS exposure, the pre-G1 fraction of the cells increased by 230% and 550%, respectively (p<0.01). At 120 min of CS exposure, the fraction of G2/M cells was lower by 47% (p<0.05) compared to controls.
  
  
  CONCLUSIONS
  CS profoundly affects the cell-cycle distribution in both SCC-15 and SCC-25 oral cancer cellular models. Such effects have been associated with DNA damage and carcinogenesis. Both models are useful for studying oral cancer pathogenesis.
authors.affiliation: Department of Molecular Pharmacology, Medical Faculty, Technion - Israel Institute of Technology, Haifa, Israel.
authors.forename: Ella
authors.initials: E
authors.lastname: Krayzler
authors.affiliation: Department of Molecular Pharmacology, Medical Faculty, Technion - Israel Institute of Technology, Haifa, Israel.
authors.forename: Rafael M
authors.initials: RM
authors.lastname: Nagler
mesh_terms: D045744:Cell Line, Tumor; D016195:G2 Phase; D006801:Humans; D008938:Mitosis; D009062:Mouth Neoplasms / Q000473:pathology*; D018307:Neoplasms, Squamous Cell / Q000473:pathology*; D012907:Smoking / Q000009:adverse effects*
keywords: Oral cancer; apoptosis; cell cycle; cigarette smoke