Determination of potential doubling times in human melanoma cell cultures subjected to irradiation and/or hyperthermia by flow cytometry

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · Radiation Research

DOI:https://doi.org/10.2307/3578695· OSTI ID:79324

Zoelzer, F; treffer, C ^[1]; Devi, P U ^[2]

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1. Universitaetsklinikum Essen (Germany)
2. Kasturba Medical College, Manipal (India)

The proliferation of human melanoma cells in vitro after irradiation and/or hyperthermia was studied by means of two-parameter flow cytometry. Cultures were incubated with BrdU for 30 min and fixed either immediately or after a delay of several hours. Cells having synthesized DNA were identified with the help of an antibody against BrdU. DNA was stained quantitatively with propidium iodide. In this way the distribution of cells in the phases of cell cycle could be determined and the movement of labeled cells through the phases of the cycle could be analyzed. Experiments in which the cell cycle distribution was studied at 4-h intervals after treatment showed the following: (1) Irradiation (4 Gy X rays) causes the expected G{sub 2} block with a maximum after 12-16 h. The proportion of S-phase cells decreases continually during the first 48 h after treatment. (2) Hyperthermia (1 h, 43{degrees}C) alone or in combination with irradiation causes a delay in S phase. The cells begin to move into G{sub 2} phase only after 12-16 h and accumulate there to some extent. From the progression of labeled cells through the cycle, the duration of S phase could be determined. Experiments and calculations of this kind were done 0, 24 and 48 h after treatment. The duration of S phase was increased only moderately (by 4 h) after irradiation, but a delay of about 30 h occurred after hyperthermia (alone or in combination with X rays). Smaller delays (up to 9 h) were observed 24 and 48 h after treatment. Two different methods were used to calculate potential doubling times. Both of them gave similar results, but a comparison with the actual population doubling times (determined by cell counting) showed that reasonable estimates could be achieved only for the untreated controls. With cultures subjected to irradiation and/or hyperthermia serious discrepancies were observed. 14 refs., 5 figs., 4 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 79324
• Journal Information: Radiation Research, Journal Name: Radiation Research Journal Issue: 3 Vol. 138; ISSN 0033-7587; ISSN RAREAE
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BIOASSAY
BIOLOGICAL RADIATION EFFECTS
CELL CULTURES
CELL CYCLE
CELL PROLIFERATION
DNA
HYPERTHERMIA
IRRADIATION
MELANOMAS
TUMOR CELLS
X RADIATION