Omega-3 polyunsaturated fatty acids and ionizing radiation: combined cytotoxicity on human colorectal adenocarcinoma cells.
Nutrition
; 22(9): 931-9, 2006 Sep.
Article
in En
| MEDLINE
| ID: mdl-16814518
ABSTRACT
OBJECTIVE:
This study evaluated whether omega-3 polyunsaturated fatty acids (PUFAs) could enhance the radiosensitivity of three different human colorectal adenocarcinoma cell lines. To understand the underlying mechanisms, the effects of omega-3 PUFAs on the cell growth, survival, and apoptosis were evaluated alone or in combination with an antioxidant (vitamin E) and compared with the effects of omega-6 PUFAs.METHODS:
LS174T, CO112, and Caco-2 cell survival was assessed by clonogenic assay after a 3-d pretreatment with omega-3/omega-6 PUFAs and/or vitamin E before a single X-ray exposure to 4 Gy. Cell growth and viability were measured by double fluorescence-activated cell sorter analyses using propidium iodide and fluorescein isothiocyanate-conjugated annexin V. Student's t test or multivariable linear regression analyses were used for comparison.RESULTS:
Preincubation with 30 to 100 micromol/L of omega-3 PUFAs induced a dose-dependent additive decrease in cell survival after irradiation (P < 0.05). Evaluation of the underlying mechanisms indicated that omega-3 PUFAs mainly decreased the cell number via apoptosis induction. Moreover, formation of lipid peroxidation products and modulation of cyclooxygenase II activity seemed to be involved, because coincubation with 10 micromol/L vitamin E abolished the effect of 50 micromol/L of omega-3 PUFAs (P < 0.05), whereas omega-6 PUFAs could partly mimic omega-3 PUFA effects.CONCLUSION:
These observations suggest that omega-3 PUFAs may be potential candidates as nutritional adjuvants to enhance the efficacy of human colorectal cancer radiotherapy.
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Database:
MEDLINE
Main subject:
Radiation, Ionizing
/
Vitamin E
/
Fatty Acids, Omega-3
/
Apoptosis
Limits:
Humans
Language:
En
Year:
2006
Type:
Article