The response of a human tumor cell line to low radiation doses: Evidence of enhanced sensitivity

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Radiation Research

DOI:https://doi.org/10.2307/3578767· OSTI ID:56772

Wouters, B G; Skarsgard, L D ^[1]

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1. British Columbia Cancer Research Centre, Vancouver (Canada)

The survival of asynchronous, exponentially growing DU-145 human tumor cells was measured after single doses of X rays in the dose range of 0.05-4 Gy using the cell sorting assay. When the response was modeled with the linear-quadratic (LQ) equation, a good fit the data was observed for dose levels above 1 Gy; however, a region of enhanced sensitivity was observed at doses less than this. One possible explanation of this low-dose substructure is that a small, sensitive subpopulation of cells is selectively killed at low doses. Modeling of the radiation response with a two-population LQ model suggests that for these data this explanation is unlikely. Another possibility is that the whole cell population is initially hypersensitive, becoming radioresistant as damage is sustained by the cell. Conceivably this radioprotective mechanism could act in one of two ways. The cell could move from a radiation-sensitive to a radiation-resistant state by a continuous function of dose, or alternatively, only after a sufficient accumulation of damage, i.e., a {open_quotes}triggering dose.{close_quotes} Both of these possibilities have been explored in the results of fitting two {open_quotes}induced resistance{close_quotes} models. 13 refs., 3 figs., 1 tab.

• Sponsoring Organization: USDOE
• OSTI ID: 56772
• Report Number(s): CONF-9305202--
• Journal Information: Radiation Research, Journal Name: Radiation Research Journal Issue: 1 Vol. 138; ISSN 0033-7587; ISSN RAREAE
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
99 GENERAL AND MISCELLANEOUS
ACCURACY
BIOLOGICAL PATHWAYS
BIOLOGICAL RADIATION EFFECTS
LOW DOSE IRRADIATION
MATHEMATICAL MODELS
RADIATION DOSES
RADIOSENSITIVITY
SURVIVAL CURVES
TUMOR CELLS
X RADIATION