Abstract
The aim of this study was to investigate how acidosis affects the sensitivity of F9 embryonal carcinoma cells to conventionally induced hyperthermia and Nd-YAG laser-induced laserthermia. Nigericin, a polyether ionophore, was used to reduce the intracellular pH to 6.8, while the control cells were maintained at a physiological pH of 7.4. Acidosis increased the heat sensitivity significantly. After the water bath only 75% of the acidotic F9S1 cells were viable, whereas all of the control cells at pH 7.4 survived. When the laser was used, the difference was even more pronounced. Only 9% of the acidotic cells were viable after a 2-min treatment and 0.2% after a 4-min treatment. At physiological pH a 2-min treatment left 41% of the cells viable and a 4-min treatment 2%. This study showed that laserthermia is significantly more effective in killing cells with low intracellular pH than it is in killing cells with normal intracellular pH. The core of a tumour is often acidotic and thus radioresistant. It is suggested that laserthermia could be a good choice when treating acidotic radioresistant cancer cells, and its effect as an adjuvant to radiation therapy should be investigated.
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Castrén-Persons, M. Laserthermia kills acidotic cancer cells more effectively than conventional hyperthermia. Laser Med Sci 10, 31–36 (1995). https://doi.org/10.1007/BF02133161
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DOI: https://doi.org/10.1007/BF02133161