title: Interaction of ω-3 polyunsaturated fatty acids with radiation therapy in two different colorectal cancer cell lines.
abstract: OBJECTIVE
  This study aims at evaluating if docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) increases the efficacy of radiation therapy (RT) on two human colorectal cancer cell lines with different radio-sensitivity.
  
  
  METHODS
  LS174T and HT-29 cells were treated with 20 or 50 μmol/L EPA or DHA followed by single X-ray RT of 0, 2 or 4 Gy, to evaluate cell survival, apoptosis, peroxide and malondialdehyde productions. Inflammation- and apoptosis-related proteins were analyzed by Western Blot. ANOVAs were used for statistical analysis.
  
  
  RESULTS
  LS174T was more sensitive to RT than HT-29. DHA and to a lesser extent EPA increased cell death, apoptosis and peroxide production after RT in LS174T and to a lesser extent in HT-29 (p < 0.05). This was associated with increased expression of heat shock protein 70, decreased expression of NF-kB p65, COX-2 and Bcl-2 proteins.
  
  
  CONCLUSIONS
  The effect of RT combination with DHA and to a lesser extent EPA was synergistic in the radio-sensitive LS174T cells, but additive in the radio-resistant HT-29 cells. This enhanced cytotoxicity was provoked at least partly by lipid peroxidation, which consequently modulated inflammatory response and induced apoptosis.
authors.affiliation: Clinical Nutrition, Geneva University Hospital, Geneva 1211, Switzerland.
authors.forename: Fang
authors.initials: F
authors.lastname: Cai
authors.affiliation: Swiss Centre for Applied Human Toxicology, University of Geneva, Switzerland.
authors.forename: Olivier
authors.initials: O
authors.lastname: Sorg
authors.affiliation: Clinical Nutrition, Geneva University Hospital, Geneva 1211, Switzerland.
authors.forename: Virginie
authors.initials: V
authors.lastname: Granci
authors.affiliation: Clinical Nutrition, Geneva University Hospital, Geneva 1211, Switzerland.
authors.forename: Elena
authors.initials: E
authors.lastname: Lecumberri
authors.affiliation: Radio-Oncology, Geneva University Hospital, Switzerland.
authors.forename: Raymond
authors.initials: R
authors.lastname: Miralbell
authors.affiliation: Clinical Nutrition, Geneva University Hospital, Geneva 1211, Switzerland.
authors.forename: Yves M
authors.initials: YM
authors.lastname: Dupertuis
authors.affiliation: Clinical Nutrition, Geneva University Hospital, Geneva 1211, Switzerland. Electronic address: Claude.Pichard@unige.ch.
authors.forename: Claude
authors.initials: C
authors.lastname: Pichard
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D015179:Colorectal Neoplasms / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D019073:HT29 Cells; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects / Q000528:radiation effects; D008315:Malondialdehyde / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D011878:Radiotherapy
chemical_list: D015525:Fatty Acids, Omega-3; D016328:NF-kappa B; D008315:Malondialdehyde
keywords: 2,4-dinitrophenylhydrazine; CRC; DHA; DNPH; Docosahexaenoic acid; EDTA; EPA; Eicosapentaenoic acid; Ethylenediaminetetraacetic acid; FACS; FITC; HPLC; Human colorectal adenocarcinoma; Lipid peroxidation; MDA; PBS; RT; Radiation therapy; SDS-PAGE; colorectal adenocarcinoma; docosahexaenoic acid; eicosapentaenoic acid; fluorescein isothiocyanate; fluorescence-activated cell sorting; high-performance liquid chromatography; malondialdehyde; phosphate-buffered saline; radiation therapy; sodium dodecyl sulfate-polyacrylamide gel electrophoresis; ω-3 PUFAs; ω-3 polyunsaturated fatty acids