title: Repair of radiation induced damage in two human tumour cell lines grown as spheroids and monolayers.
abstract: Growth curves of two human tumour cell lines grown as multicellular tumour spheroid (MTS) were used to obtain survival estimates by back-extrapolation after split and single dose irradiation. Neuroblastoma (NB-100) and squamous cell carcinoma (HN-1) single cells from monolayer culture were assessed for repair of sublethal and potentially lethal damage. The extent of repair was calculated on an iso-effect basis. When grown as spheroids squamous cell carcinoma cells showed a higher capacity to repair sublethal damage than neuroblastoma cells. Repair of potentially lethal damage did not contribute to this higher capacity of HN-1 cells, since this cell line was found to be deficient for this type of repair. Using the recovery ratio to estimate the beta-component of the survival curves, it was found that differences in repair capacity were determined by the alpha-component of the equation. Our results show the feasibility of back-extrapolating multicellular tumour spheroid growth curves to obtain survival estimates that can be applied to establish sublethal damage repair capacity.
authors: Department of Radiotherapy, University Hospital, Nijmegen, The Netherlands.
authors: J H
authors: JH
authors: Schwachöfer
authors: R P
authors: RP
authors: Crooijmans
authors: G F
authors: GF
authors: Borm
authors: J J
authors: JJ
authors: van Gasteren
authors: J
authors: J
authors: Hoogenhout
authors: H B
authors: HB
authors: Kal
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000473:pathology; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects; D004249:DNA Damage / Q000528:radiation effects*; D004260:DNA Repair / Q000528:radiation effects*; D004273:DNA, Neoplasm / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D009447:Neuroblastoma / Q000473:pathology; D011832:Radiation Injuries / Q000473:pathology*; D011836:Radiation Tolerance; D014062:Tongue Neoplasms / Q000473:pathology; D014407:Tumor Cells, Cultured / Q000528:radiation effects
chemical_list: D004273:DNA, Neoplasm