title: Gene expression profile of 5-fluorouracil metabolic enzymes in laryngeal cancer cell line: predictive parameters for response to 5-fluorouracil-based chemotherapy.
abstract: BACKGROUND
  5-fluorouracil (5-FU) is an antifolate chemotherapeutic that has become established in many therapeutic regimes, but sensitivity variations and development of resistance are common problems that limit the efficiency of the treatments. Inter-individual variations to 5-FU outcome have been attributed to different expression profiles of genes related to folate metabolism.
  
  
  METHODS
  To elucidate the mechanisms of variations to 5-FU outcome, the authors investigated MTHFR, DHFR, TYMS and SLC19A1 folate genes expression for 5-FU response in laryngeal cancer cell line (Hep-2). Concentrations of 10, 50, and 100 ng/mL of 5-FU chemotherapeutic were added separately in Hep-2 cell line for 24 hours at 37 °C. Cell sensibility was evaluated with fluorescein isothiocyanate (FITC) label Bcl-2 by flow cytometry. The real-time quantitative PCR (qPCR) technique was performed for quantiﬁcation of gene expression using TaqMan(®) Gene Expression Assay. ANOVA and Bonferroni's post hoc tests were utilized to statistical analysis.
  
  
  RESULTS
  The numbers of viable Hep-2 cells with 10, 50, and 100 ng/mL concentrations of 5-FU chemotherapy were 15.87, 28.3 and 68.9%, respectively. Statistical analysis showed significant association between control group and increased expression for TYMS gene in cells treated with 100 ng/mL/5-FU chemotherapy (P<0.05).
  
  
  CONCLUSIONS
  The authors found association between the highest 5-FU dose chemotherapy and increased expression levels for TYMS folate gene in laryngeal cancer cell line. Although these experiments were performed in vitro, the results suggest that genetic factors are thought to play an important role in drug metabolism and may be useful for predicting treatment outcomes.
authors.affiliation: FAMERP- São José do Rio Preto Medical School Genetics and Molecular Biology Research Unit - UPGEM AV Brigadeiro Faria Lima, 5416 São José do Rio Preto, 15090000 Brazil. Electronic address: analivia_sg@yahoo.com.br.
authors.forename: Ana Lívia Silva
authors.initials: AL
authors.lastname: Galbiatti
authors.affiliation: FAMERP - Laboratory of Experimental Immunology and Transplantation/LITEX, Brazil.
authors.forename: Heloisa Cristina
authors.initials: HC
authors.lastname: Caldas
authors.affiliation: FAMERP - Otorhinolaryngology and Head and Neck Surgery Department, Brazil.
authors.forename: José Victor
authors.initials: JV
authors.lastname: Maniglia
authors.affiliation: FAMERP- São José do Rio Preto Medical School Genetics and Molecular Biology Research Unit - UPGEM AV Brigadeiro Faria Lima, 5416 São José do Rio Preto, 15090000 Brazil.
authors.forename: Erika Cristina
authors.initials: EC
authors.lastname: Pavarino
authors.affiliation: FAMERP- São José do Rio Preto Medical School Genetics and Molecular Biology Research Unit - UPGEM AV Brigadeiro Faria Lima, 5416 São José do Rio Preto, 15090000 Brazil.
authors.forename: Eny Maria
authors.initials: EM
authors.lastname: Goloni-Bertollo
mesh_terms: D000704:Analysis of Variance; D045744:Cell Line, Tumor; D005434:Flow Cytometry; D005472:Fluorouracil / Q000378:metabolism* / Q000494:pharmacology / Q000627:therapeutic use; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007822:Laryngeal Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000235:genetics*; D016896:Treatment Outcome
chemical_list: D005472:Fluorouracil
keywords: Fluorouracil; Gene expression; Laryngeal neoplasms