title: Effect of hypothermic irradiation of the growth characteristics of two human cell lines.
abstract: The effect of hypothermic irradiation on the growth characteristics of two human cell lines was investigated. Low temperature (2 degrees C) X-irradiation of MCF-7 cells (2, 3 and 4 Gy) resulted in higher surviving fractions compared to irradiation at 37 degrees C as assessed by the colony forming assay. The ratios for the surviving fraction between the two temperatures were 1.2, 1.5 and 1.7 at 2, 3 and 4 Gy, respectively. Correspondingly, the dose modifying factor was 1.23. The distribution of colony sizes (of those with more than 50 cells) was different with proportionally more small-sized colonies from cells irradiated at 2 degrees C. Colonies from diploid fibroblasts (HS27) were ill-defined and could not be counted. In conclusion, hypothermia during irradiation seems to influence the radioresponse in MCF-7 cells. The growth in multiwell plates of MCF-7 cells and human diploid fibroblasts (HS27) after irradiation with 3 and 4 Gy, respectively, at 2 degrees C or 37 degrees C was assessed by using the crystal violet growth assay. No difference between 2 degrees C or 37 degrees C irradiation was found for either of the two cell lines.
authors.affiliation: Göteborg University, Department of Oncology, Sahlgrenska University Hospital, SE-413 45, Göteborg, Sweden. Kecke.elmroth@oncology.gu.se
authors.forename: K
authors.initials: K
authors.lastname: Elmroth
authors.forename: J
authors.initials: J
authors.lastname: Nygren
authors.forename: L J
authors.initials: LJ
authors.lastname: Erkell
authors.forename: R
authors.initials: R
authors.lastname: Hultborn
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000532:radiotherapy / Q000628:therapy; D001943:Breast Neoplasms / Q000473:pathology* / Q000532:radiotherapy / Q000628:therapy; D002455:Cell Division / Q000528:radiation effects; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects; D003080:Cold Temperature; D005347:Fibroblasts / Q000166:cytology* / Q000528:radiation effects*; D005840:Gentian Violet; D006801:Humans; D006979:Hyperthermia, Induced; D014407:Tumor Cells, Cultured / Q000528:radiation effects*; D014410:Tumor Stem Cell Assay
chemical_list: D005840:Gentian Violet