Hyperthermic survival of Chinese hamster ovary cells as a function of cellular population density at the time of plating

Journal Article · Sun Jan 01 04:00:00 EST 1984 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3576195· OSTI ID:5177350

Highfield, D P; Holahan, E V; Holahan, P K; Dewey, W C

The survival of synchronous G/sub 1/ or asynchronous Chinese hamster ovary cells in vitro to heat treatment may depend on the cellular population density at the time of heating and/or as the cells are cultured after heating. The addition of lethally irradiated feeder cells may increase survival at 10/sup -3/ by as much as 10- to 100-fold for a variety of conditions when cells are heated either in suspension culture or as monolayers with or without trypsinization. The protective effect associated with feeder cells appears to be associated with close cell-to-cell proximity. However, when cells are heated without trypsinization about 24 hr or later after plating, when adaptation to monolayer has occurred, the protective effect is reduced; i.e., addition of feeder cells enhances survival much less, for example, about 2- to 3-fold at 10/sup -2/-10/sup -3/ survival. Also, the survival of a cell to heat is independent of whether the neighboring cell in a microcolony is destined to live or die. Finally, if protective effects associated with cell density do occur and are not controlled, serious artifacts can result as the interaction of heat and radiation is studied; for example, survival curves can be moved upward, and thus changed in shape as the number of cells plated is increased with an increase in the hyperthermic treatment or radiation dose following hyperthermia. Therefore, to understand mechanisms and to obtain information relevant to populations of cells in close proximity, such as those in vivo, these cellular population density effects should be considered and understood.

• Research Organization: Univ. of California, San Francisco
• OSTI ID: 5177350
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 97:1; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
560201 -- Thermal Effects-- Cells-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
BODY TEMPERATURE
CELL KILLING
CHO CELLS
DATA
ELECTROMAGNETIC RADIATION
EXPERIMENTAL DATA
HYPERTHERMIA
INFORMATION
IONIZING RADIATIONS
NUMERICAL DATA
POPULATION DYNAMICS
RADIATIONS
RADIOINDUCTION
RADIOSENSITIVITY
RADIOSENSITIVITY EFFECTS
SURVIVAL CURVES
TEMPERATURE EFFECTS
X RADIATION