Hypothermic modulation of doxorubicin, cisplatin and radiation cytotoxicity in vitro.

BACKGROUND

The influence of hypothermia on doxorubicin, cisplatin and radiation cytotoxicity was investigated in vitro.

MATERIALS AND

METHODS

A human glioma cell line (251MG) in early exponential growth was exposed to doxorubicin or cisplatin at various concentrations for 4 hours, or X-irradiation at 28 degrees C or 37 degrees C. The cells continued growing in multi-well plates at 37 degrees C and were counted every third day until the end of the logarithmic phase, on day 13.

RESULTS

Exposure to doxorubicin 0.05-0.5 microg/ml or cisplatin 1-10 microg/ml caused a dose-dependent inhibition of cell growth with a significantly reduced toxicity when exposed at 28 degrees C as compared to 37 degrees C. Irradiation with 4 Gy also resulted in less toxicity during hypothermia. Chlorpromazine 0.01-10 microg/ml, used to induce hypothermia in vivo (1), neither influenced, cellular growth itself nor interacted with doxorubicin, cisplatin or irradiation.

CONCLUSION

Moderate hypothermia (28 degrees C) appears to protect against the cellular insult of doxorubicin, cisplatin and ionising irradiation and their consequences.