Cellular transformation by radiation: induction, promotion, and inhibition

Journal Article · Thu Jan 01 04:00:00 EST 1981 · J. Supramol. Struct. Cell. Biochem.; (United States)

DOI:https://doi.org/10.1002/jsscb.1981.380160403· OSTI ID:5208530

Borek, C

Radiation oncogenesis induced in utero in hamsters is expressed at a lower frequency than that induced in vitro. Quantitative studies carried out on hamster embryo cells indicate that neutrons are more effective in their carcinogenic potential than x-rays but also more toxic, that splitting the dose of x-rays at low doses leads to enhanced transformation, but that at high doses protracted radiation has a sparing effect. At all dose ranges survival was increased by protracting the radiation dose, thus suggesting that different repair processes must be involved for survival and transformation. In our qualitative studies, once cells are transformed by radiation, they exhibit a wide range of structural and functional phenotypic changes, some of which are membrane-associated and are expressed within days after induction. Our current studies on nutritional and hormonal influences on radiation transformation indicate the following: Pyrolysate products from broiled protein foods act in synergism with radiation to produce transformation, whereas vitamin A analogs are powerful, preventive agents. Retinoids inhibit both x-ray-induced transformation and its promotion by TPA; these modifications (enhancement by TPA, inhibition by retinoids) are not reflected in sister chromatid exchanges, but are reflected in the level of membrane associated enzymes Na/K ATPase. Whereas retinoids modify late events (expression, promotion), we find that thyroid hormone plays a crucial role in the early phases of radiation and chemically induced transformation. Our recent success in transforming human skin fibroblasts will enable quantitative and qualitative studies of radiation carcinogenesis in a system relevant to man.

• Research Organization: Department of Radiology, Columbia University College of Physicians and Surgeons, New York
• OSTI ID: 5208530
• Journal Information: J. Supramol. Struct. Cell. Biochem.; (United States), Journal Name: J. Supramol. Struct. Cell. Biochem.; (United States) Vol. 16:4; ISSN JSSBD
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BARYONS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BODY
CARCINOGENESIS
CELL CULTURES
CHROMOSOMAL ABERRATIONS
CONNECTIVE TISSUE CELLS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENZYME INHIBITORS
ENZYMES
FERMIONS
FIBROBLASTS
HADRONS
HAMSTERS
HORMONES
HYDROLASES
IONIZING RADIATIONS
IRRADIATION
LOW DOSE IRRADIATION
MAMMALS
MAN
MUTATIONS
NEUTRONS
NUCLEONS
ONCOGENIC TRANSFORMATIONS
ORGANS
PATHOGENESIS
PEPTIDE HORMONES
PRIMATES
RADIATION EFFECTS
RADIATION QUALITY
RADIATIONS
RADIOINDUCTION
RECOVERY
REPAIR
RESPONSE MODIFYING FACTORS
RODENTS
SISTER CHROMATID EXCHANGES
SKIN
SOMATIC CELLS
TEMPERATURE DEPENDENCE
THYROID HORMONES
VERTEBRATES
VITAMIN A
VITAMINS
X RADIATION