Effects of hyperthermia on survival and progression of Chinese hamster ovary cells

Journal Article · Wed Feb 01 04:00:00 EST 1978 · Cancer Res.; (United States)

OSTI ID:7027189

Sapareto, S A; Hopwood, L E; Dewey, W C; Raju, M R; Gray, J W

The survival of Chinese hamster ovary cells exposed to hyperthermic temperatures of 42.5 to 46.0/sup 0/ decreases exponentially as a function of duration of heat exposure in a manner quite similar to survival as a function of radiation dose. The data indicate that above 43/sup 0/ a 1/sup 0/ change in temperature requires a 2-fold change in time to achieve the same degree of killing, whereas below 43/sup 0/ the same 2-fold change in time requires only a 0.5/sup 0/ change in temperature for the same effect. An Arrhenius-type plot of the logarithm of the rate of killing as a function of reciprocal temperature exhibits linearity with a change in slope at 43/sup 0/. This change in slope suggests either a change in the mechanism of cell killing below this temperature or a manifestation of thermal tolerance that is readily observed when the duration of heating exceeds 4 to 5 hr. Thermotolerance to 45.5/sup 0/, as evidenced by a 3- to 4-fold increase in D/sub 0/, is observed in synchronous G/sub 1/ cells exposed to heat 20 hr after an initial heat dose. This thermotolerance develops, although no progression of cells into S phase occurs during this period. In addition, thermotolerance develops in both asynchronous and synchronous G/sub 1/ cells exposed to single heat doses between 41.5 and 42.5/sup 0/ for periods exceeding 4 to 5 hr, i.e., survival decreases exponentially as a function of duration of heating up to 4 to 5 hr, after which survival decreases very little. At 42.0 to 42.5/sup 0/, survival is extremely sensitive to changes in temperature, with as much as a 10-fold difference in survival for a 0.1/sup 0/ difference in temperature with heat exposures greater than 4 hr. Cell cycle delays are observed for cells continuously exposed to temperatures of 41.5/sup 0/. Data indicate the importance of careful treatment design and precise temperature control if hyperthermia is to be used for cancer therapy.

• Research Organization: Colorado State Univ., Fort Collins
• OSTI ID: 7027189
• Journal Information: Cancer Res.; (United States), Journal Name: Cancer Res.; (United States) Vol. 38:2; ISSN CNREA
• Country of Publication: United States
• Language: English

Related Subjects

550300* -- Cytology
550600 -- Medicine
560201 -- Thermal Effects-- Cells-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BIOLOGICAL ADAPTATION
BIOLOGICAL EFFECTS
BODY
BODY TEMPERATURE
CELL CYCLE
CELL DIVISION
CELL KILLING
DISEASES
DNA
DOSES
FEMALE GENITALS
GONADS
HAMSTERS
HYPERTHERMIA
MAMMALS
MEDICINE
MITOSIS
NEOPLASMS
NUCLEAR MEDICINE
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANS
OVARIES
RADIATION DOSES
RADIOLOGY
RADIOTHERAPY
RODENTS
THERAPY
TOLERANCE
VERTEBRATES