12-O-Tetradecanoyl-phorbol-13-acetate and its relationship to SCE induction in Syrian and Chinese hamster cells
12-O-Tetradecanoyl-phorbol-13-acetate (TPA) in conditions that produce enhancement of ultraviolet light (UV) and x-irradiation Syrian hamster embryo cell (HEC) transformation did not cause further increase in the sister chromatid exchange (SCE) frequency induced by UV and x-irradiation, two physical carcinogens that differ in their mode of DNA interaction and efficiency of SCE induction. Several factors which might influence SCE induction by TPA were studied on HEC and Chinese hamster V79-4 cells. Heat-inactivated serum was used because of the possibility that a serum component may interfere with TPA ability to cause SCE. TPA effect on SCE was determined at the first and second division post treatment on cells exposed to different 5-bromodeoxyuridine (BrdUrd) concentrations. Independent of BrdUrd concentration (1-10..mu..g/ml medium) and the number of cells divisions post treatment, TPA (0.01-2..mu..g/ml medium) was ineffective in inducing SCE in exponentially and stationary HEC cultures cultivated in medium supplemented with heat-inactivated serum. Also, TPA did not increase the SCE frequency in V79-4 Chinese hamster cells cultured in heat-activated or noninactivated serum. Although SCE induction, a cellular response to carcinogen-induced DNA damage, may be important for the induction of transformation by environmental agents, the enhancement of transformation frequency caused by TPA occurs without further DNA alterations involved in SCE formation.
- Research Organization:
- National Cancer Inst., Bethesda, MD
- OSTI ID:
- 5174204
- Journal Information:
- Environ. Mutagen.; (United States), Vol. 4:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CELL CULTURES
EXTERNAL IRRADIATION
EMBRYOS
SISTER CHROMATID EXCHANGES
BIOASSAY
BIOLOGICAL EFFECTS
HAMSTERS
PHORBOL ESTERS
RESPONSE MODIFYING FACTORS
TUMOR PROMOTERS
ULTRAVIOLET RADIATION
X RADIATION
ANIMALS
CARCINOGENS
CHROMOSOMAL ABERRATIONS
ELECTROMAGNETIC RADIATION
ESTERS
IONIZING RADIATIONS
IRRADIATION
MAMMALS
MUTATIONS
ORGANIC COMPOUNDS
PROMOTERS
RADIATIONS
RODENTS
VERTEBRATES
560121* - Radiation Effects on Cells- External Source- (-1987)