Effects of differential-inducing agents on the radiation response of human colon adenocarcinoma cells in vitro
This study was undertaken to investigate, in depth, the radiation responses of two tumor subpopulations obtained from a heterogeneous human colon adenocarcinoma. Of particular interest were the effects of differentiation-inducing agents on these tumor cells in vitro. These two subpopulations were found to differ significantly in their intrinsic sensitivity to x-irradiation when exponentially growing control cells were irradiated with single doses of x-rays. However, no significant differences were found between the radiation responses of these two subpopulations in the plateau phase of growth. Clone D cells always expressed a greater amount of PLDR than clone a cells regardless of the nutritional state examined. The magnitude of expression of sublethal damage recovery (SLDR) was the same for both cell lines. The effects of the differentiating agents, N,N-dimethylformamide (DMF), sodium butyrate (NaB), 5-azacytidine (5-aza-CR), and 5-aza-2'-deoxycytidine (5-aza-CdR) on intrinsic radiosensitivity and recovery processes were investigated in plateau phase cultures treated with the agents for three passages in vitro. Using a typical clinical radiation dose of 2 Gy for comparison, both DMF and NaB enhanced radiation cell killing in the low dose (shoulder) region of the survival curves for both of the tumor subpopulations. These studies indicate that differentiation-inducing agents can significantly modify the radiation response of human tumor cells in vitro and the nature of these changes may impact strongly on any combined modality therapy involving their use.
- Research Organization:
- Brown Univ., Providence, RI (USA)
- OSTI ID:
- 6545463
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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AMIDES
RADIOSENSITIVITY EFFECTS
BUTYRIC ACID
CELL KILLING
RADIOINDUCTION
CYTIDINE
ANTIMETABOLITES
BIOLOGICAL REPAIR
CARBOXYLIC ACID SALTS
CARCINOMAS
CELL DIFFERENTIATION
IN VITRO
LARGE INTESTINE
MAN
SURVIVAL CURVES
TUMOR CELLS
X RADIATION
ANIMAL CELLS
ANIMALS
AZINES
BIOLOGICAL RECOVERY
BODY
CARBOXYLIC ACIDS
DIGESTIVE SYSTEM
DISEASES
DRUGS
ELECTROMAGNETIC RADIATION
GASTROINTESTINAL TRACT
HETEROCYCLIC COMPOUNDS
INTESTINES
IONIZING RADIATIONS
MAMMALS
MONOCARBOXYLIC ACIDS
NEOPLASMS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PRIMATES
PYRIMIDINES
RADIATIONS
RECOVERY
REPAIR
RIBOSIDES
VERTEBRATES
560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture