title: Effect of 41 degrees C and 43 degrees C on cisplatin radiosensitization in two human carcinoma cell lines with different sensitivities for cisplatin.
abstract: The effect of trimodality treatment consisting of hyperthermia, cisplatin and radiation was investigated in two cell lines with different sensitivities to cisplatin. Hyperthermia treatment was performed for 1 h at 41 degrees C and 43 degrees C in order to compare the effects of the two temperatures. Clonogenic assays were performed with cisplatin-sensitive SiHa human cervical carcinoma and cisplatin-resistant SW-1573 human lung carcinoma cell lines. Cells were treated with various combinations of hyperthermia, cisplatin and radiation. Radiation was performed after 1 h of simultaneous hyperthermia and cisplatin treatment. Cisplatin exposure was for 1 h or continuous without refreshment of the cisplatin-containing medium. SiHa cells were more sensitive to cisplatin than SW-1573 cells. Hyperthermia at 41 degrees C decreased survival in SW-1573 cells but was not cytotoxic in SiHa cells. Hyperthermia at 43 degrees C decreased survival dramatically in both cell lines with SiHa being the most sensitive. The addition of hyperthermia at 41 degrees C and 43 degrees C to cisplatin treatment led to enhanced cell kill in both cell lines compared with cisplatin alone. Radiosensitization was observed after continuous but not after 1 h of cisplatin treatment. Hyperthermia at 43 degrees C increased radiosensitivity whereas hyperthermia at 41 degrees C did not. A combination of 41 degrees C hyperthermia with continuous cisplatin treatment had an additive effect on SW-1573 cells but enhanced cisplatin radiosensitivity of SiHa cells. In SW-1573 cells trimodality treatment using 43 degrees C hyperthermia enhances cisplatin radiosensitivity. We conclude that hyperthermia at 43 degrees C enhances cisplatin-induced radiosensitization in both cisplatin-sensitive and -resistant cell lines. Hyperthermia at 41 degrees C was also able to increase cisplatin-induced radiosensitivity but only in the cisplatin-sensitive SiHa cell line.
authors.affiliation: Academic Medical Center, LEXOR/Department of Radiotherapy, University of Amsterdam, 1100 DE Amsterdam, The Netherlands. j.w.bergs@amc.uva.nl
authors.forename: Judith W J
authors.initials: JW
authors.lastname: Bergs
authors.forename: Jaap
authors.initials: J
authors.lastname: Haveman
authors.forename: Rosemarie
authors.initials: R
authors.lastname: Ten Cate
authors.forename: Jan Paul
authors.initials: JP
authors.lastname: Medema
authors.forename: Nicolaas A P
authors.initials: NA
authors.lastname: Franken
authors.forename: Chris
authors.initials: C
authors.lastname: Van Bree
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000532:radiotherapy / Q000628:therapy*; D002945:Cisplatin / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D019008:Drug Resistance, Neoplasm; D005260:Female; D005720:Gamma Rays; D006801:Humans; D006979:Hyperthermia, Induced; D008175:Lung Neoplasms / Q000188:drug therapy / Q000532:radiotherapy / Q000628:therapy*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000528:radiation effects; D002583:Uterine Cervical Neoplasms / Q000188:drug therapy / Q000532:radiotherapy / Q000628:therapy*
chemical_list: D000970:Antineoplastic Agents; D002945:Cisplatin