Affiliation: | * Department of Radiation Physics, Malmö University Hospital, Malmö, Sweden † Department of Oncology, University Hospital, Lund, Sweden ‡ Department of Otorhinolaryngology, Head and Neck, University Hospital, Lund, Sweden |
Abstract: | Purpose: The aim of the present work was to examine the effect of 191Pt-cisplatin, and to study the manner in which radiation and cisplatin interact, in a human cervical carcinoma cell line (ME-180). Methods and Materials: The cells were incubated for 1 hour with nonradioactive cisplatin or 191Pt-cisplatin with specific activities in the range 48–167 MBq/mg. The surviving fraction of the cells after 7 days’ growth was determined with a nonclonogenic tetrazolium-based (MTT) assay. The uptake of platinum into the cell and the amount of platinum bound to DNA was measured. Results: The 50% inhibition concentration (IC50) decreased with increasing specific activity of the 191Pt-cisplatin. For the specific activities 0 (nonradioactive), 48, 89, 143, 157, and 167 MBq/mg, IC50 was found to be 3.24 ± 0.08, 2.77 ± 0.55, 2.17 ± 0.34, 1.15 ± 0.04, 1.02 ± 0.03, and 0.76 ± 0.13 respectively. Isobologram analysis showed a supra-additive (synergistic) interaction between the radiotoxicity and chemotoxicity for specific activities over 100 MBq/mg. Conclusion: The cytotoxic effect of cisplatin may be enhanced by labeling the drug with the radionuclide 191Pt. |