Transformation of Mammalian Cells in vitro by Low Doses of X-rays

Nature ◽  
1973 ◽  
Vol 243 (5408) ◽  
pp. 450-453 ◽  
Author(s):  
CARMIA BOREK ◽  
ERIC J. HALL
Keyword(s):  
Mammalian Cells ◽  
Low Doses ◽  
X Rays

Dose Patterns of Cellular Effects Induced by Carcinogens: Evidence for the Presence or Absence of Thresholds

1983 ◽  
Vol 2 (3) ◽  
pp. 185-193
Author(s):  
Jerry R. Williams ◽  
Peter D'Arpa
Keyword(s):  
Mammalian Cells ◽  
Cellular Response ◽  
Response Curve ◽  
Human Populations ◽  
Low Doses ◽  
Human Beings ◽  
Environmental Carcinogens ◽  
Cellular Effects ◽  
Cancer Induction

The patterns of response of individual cells to carcinogens may be a factor that influences the shape of the dose-response curve for cancer in human populations; thus the existence of a threshold for cellular response may imply a threshold for cancer induction. The patterns of response of cultured mammalian cells to carcinogen treatment is described for four cellular endpoints: cytotoxidty, mutation, sister chromatid exchange, and in vitro transformation. These data, taken in toto, indicate that for some carcinogens a threshold exists for the induction of cellular effects, but for some carcinogens thresholds probably do not exist. Cancer-prone human beings may contain cell populations without thresholds, making them especially sensitive to low doses of environmental carcinogens.

USE OF I125-LABELED 5-IODO-2′-DEOXYURIDINE FOR THE MEASUREMENT OF DNA SYNTHESIS IN MAMMALIAN CELLS IN VITRO

1963 ◽  
Vol 41 (11) ◽  
pp. 2343-2351 ◽  
Author(s):  
S. Mak ◽  
J. E. Till
Keyword(s):  
Dna Synthesis ◽  
Mammalian Cells ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
X Rays ◽  
Beta Particles ◽  
Deoxyribonucleic Acid Synthesis ◽  
Gamma Emitter

The use of isotopically labeled 5-iodo-2′-deoxyuridine (I125UdR) for determination of the rate of deoxyribonucleic acid synthesis in mammalian cells in vitro has been investigated. The results obtained indicate that for this purpose I125UdR is a suitable substitute for the more commonly used DNA precursor, tritium-labeled thymidine (H3TdR). I125UdR appears to be incorporated specifically into the DNA of cells in culture, and has been demonstrated to compete with H3TdR, although the Km for H3TdR was smaller than that of I125UdR by a factor of approximately 4. The amount of label incorporated into DNA of cells increased linearly with time. When the rate of DNA synthesis was reduced by exposure of the cells to various doses of X-rays, the ratio of I125UdR incorporation to H3TdR incorporation into DNA of cells was found to be a constant, which supports the view that uptake of the analogue provides as reliable an indication of effects upon the rate of DNA synthesis as does that of H3TdR. The chief advantage of I125UdR over H3TdR is that I125 is a gamma emitter, so that the difficulties encountered in detection of the low energy beta particles from H3 may be avoided.

scholarly journals ACTION OF X-RAYS ON MAMMALIAN CELLS

1957 ◽  
Vol 106 (4) ◽  
pp. 485-500 ◽  
Author(s):  
Theodore T. Puck ◽  
Dimitry Morkovin ◽  
Philip I. Marcus ◽  
Steven J. Cieciura
Keyword(s):  
Survival Data ◽  
Mammalian Cells ◽  
Radiation Effects ◽  
Lethal Dose ◽  
Human Cells ◽  
X Rays ◽  
Survival Curves ◽  
Isolated Cells ◽  
X Irradiation

Survival curves of normal human cells from a variety of tissues exposed to varying doses of x-irradiation have been constructed, which permit definition of the intrinsic radiation sensitivity of the reproductive power of each cell type. The mean lethal dose of x-irradiation for all the cells employed, including those from normal and cancerous organs, those exhibiting diploid and polyploid chromosome number; those from embryonic and adult tissues, including recently isolated cells and cultures which had been maintained in vitro for many years, and cells exhibiting either epithelioid or fibroblastic morphology, was found to be contained between the limits of 50 to 150 r. Other similarities in the pattern of radiation effects, such as giant formation and abortive colonial growth, in these cells and that of the HeLa S3, previously studied, confirm the hypothesis that the pattern of reaction to x-irradiation previously elucidated, is representatative, at least in over-all outline, for a large variety of human cells. While the radiation survival curves of various human cells are similar in the gross, small but important characterizing differences have been found. All epithelioid cells so far studied are approximately 2-hit, and more radioresistant than the fibroblast-like cells whose survival data correspond to a mean lethal dose of around 60 r, and which so far can be fitted by either 1-hit or 2-hit curves. The earlier prediction that the major radiobiologic damage to mammalian cells is lodged in the genetic apparatus was confirmed by the demonstration of high frequency of mutants among the survivors of doses of 500 to 900 r. All the data on the x-radiosensitivity of these cells can be explained on the basis of a defect resulting from primary damage localized in one or more chromosomes. These considerations afford a convincing explanation of several aspects of the mammalian radiation syndrome.

VISUALIZATION OF THE DNA REPAIR PROCESS IN MAMMALIAN CELLS TRANSFECTED WITH EGFP-EXPRESSING PLASMID DNA AFTER EXPOSURE TO X-RAYS IN VITRO

2018 ◽  
Vol 183 (1-2) ◽  
pp. 79-83
Author(s):  
Hiroki Nakaue ◽  
Yui Obata ◽  
Kiichi Kaminaga ◽  
Nobuyoshi Akimitsu ◽  
Akinari Yokoya
Keyword(s):  
Dna Repair ◽  
Plasmid Dna ◽  
Mammalian Cells ◽  
Repair Process ◽  
X Rays

USE OF I125-LABELED 5-IODO-2′-DEOXYURIDINE FOR THE MEASUREMENT OF DNA SYNTHESIS IN MAMMALIAN CELLS IN VITRO

1963 ◽  
Vol 41 (1) ◽  
pp. 2343-2351 ◽  
Author(s):  
S. Mak ◽  
J. E. Till
Keyword(s):  
Dna Synthesis ◽  
Mammalian Cells ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
X Rays ◽  
Beta Particles ◽  
Deoxyribonucleic Acid Synthesis ◽  
Gamma Emitter

The use of isotopically labeled 5-iodo-2′-deoxyuridine (I125UdR) for determination of the rate of deoxyribonucleic acid synthesis in mammalian cells in vitro has been investigated. The results obtained indicate that for this purpose I125UdR is a suitable substitute for the more commonly used DNA precursor, tritium-labeled thymidine (H3TdR). I125UdR appears to be incorporated specifically into the DNA of cells in culture, and has been demonstrated to compete with H3TdR, although the Km for H3TdR was smaller than that of I125UdR by a factor of approximately 4. The amount of label incorporated into DNA of cells increased linearly with time. When the rate of DNA synthesis was reduced by exposure of the cells to various doses of X-rays, the ratio of I125UdR incorporation to H3TdR incorporation into DNA of cells was found to be a constant, which supports the view that uptake of the analogue provides as reliable an indication of effects upon the rate of DNA synthesis as does that of H3TdR. The chief advantage of I125UdR over H3TdR is that I125 is a gamma emitter, so that the difficulties encountered in detection of the low energy beta particles from H3 may be avoided.

Low doses of diagnostic energy X-rays protect against neoplastic transformation in vitro

2003 ◽  
Vol 79 (4) ◽  
pp. 235-240 ◽  
Author(s):  
J. L. REDPATH ◽  
Q. LU ◽  
X. LAO ◽  
S. MOLLOI ◽  
E. ELMORE
Keyword(s):  
Neoplastic Transformation ◽  
Low Doses ◽  
X Rays
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