Cytotoxicity of restriction enzyme-induced DNA strand breaks in radiosensitive and radioresistant human tumor cell lines
- Harvard School of Public Health, Boston, MA (United States)
The purpose was to examine the role of sensitivity to specific types of DNA double strand breaks in human tumor cell response. The X ray-sensitive human squamous carcinoma cell line SCC-61 and the X ray-resistant line SQ-20B were exposed to the restriction enzymes HaeIII, HinfI, PvuII, BamHI by electroporation. Cyotoxicity of these restriction endonucleases was measured by a colony formation assay. Cell killing by each enzyme occurred in a concentration-dependent manner. The radiosensitive cell line was more sensitive to all four restriction enzymes than the radioresistant line, paralleling the response to ionizing radiation. However, the magnitude of the difference was smaller than for radiation. The 5-base sticky ended cutter HinfI and 6-base blunt ended cutter PvuII were much more effective in killing cells from both lines than BamHI, a 6-base sticky ended cutter, whereas the 4-base blunt ended cutter HaeIII was intermediate in its effectiveness. Thus, enzyme sensitivity could not be related to the type of cutter or the distance between cutting sites. 14 refs., 1 fig., 2 tabs.
- OSTI ID:
- 6574091
- Journal Information:
- International Journal of Radiation Oncology, Biology and Physics; (United States), Vol. 27:2; ISSN 0360-3016
- Country of Publication:
- United States
- Language:
- English
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CARCINOMAS
RADIOSENSITIVITY
ENDONUCLEASES
GENETIC EFFECTS
BIOLOGICAL EFFECTS
DISEASES
DNA-ASE
ENZYMES
ESTERASES
HYDROLASES
NEOPLASMS
ORGANIC COMPOUNDS
PHOSPHODIESTERASES
PROTEINS
550200* - Biochemistry
560120 - Radiation Effects on Biochemicals
Cells
& Tissue Culture