Evaluation of apoptosis in four human tumour cell lines with differing sensitivities to cisplatin.

Four human tumour cell lines were evaluated for their ability to undergo apoptosis when subjected to cisplatin or hyperthermia treatment. In an ovarian carcinoma line (A2780s) and its derivative cisplatin resistant line (A2780cp) the variation in response was expressed for both the colony survival endpoint and the apoptosis endpoint. Apoptosis was measured by the number of floating cells, DNA agarose gels, and electron microscopy. In fact, cisplatin resistance was expressed to a higher level for apoptosis, than colony survival in the A2780cp cell line compared to the A2780s line. The melanoma cell line (Sk Mel-3) also showed induced apoptosis by cisplatin treatment while the glioma line (U87MG) showed little to no apoptosis in response to cisplatin treatment. Hyperthermia (43 degrees C for 1 hour) induced apoptosis in the human melanoma cell line but not in the glioma cell line. These data indicate that, while both cisplatin and hyperthermia can induce apoptosis in human tumour cell lines, the degree of induction is highly cell line dependent.