title: Effects of growth factors on growth and radiation sensitivity of the human breast cancer cell line T-47D.
abstract: Different growth factors are supposed to be involved in evolution of breast cancer. Radiation therapy is used in treatment of breast cancer patients, and the possible relationships between the influence of growth factors on cells and their radiation sensitivity are therefore of interest. Cell growth and radiation sensitivity of the human oestrogen and progesterone receptor positive cell line T-47D were investigated following exposure to the growth factors IGF-1, TGF-alpha and TGF-beta. Experiments were done with standard medium and in growth factor defined medium. Changes in cell cycle distribution were investigated by flow cytometry. The cell growth was significantly decreased by removal of growth factors in the culture medium, an effect which partly could be reversed by supplementation of growth factors. The growth factors decreased the cellular doubling time in standard medium, but to a smaller extent than seen in growth factor defined medium. The radiation sensitivity and plating efficiency were slightly affected by growth factor defined versus standard growth conditions. Additional growth factor exposure was able to some extent to change the radiation sensitivity, mainly by effects due to changes in repair of sublethal damage. Only minor changes were seen in phase distribution of these cells. Cellular growth was dependent on presence of different growth factors, and changes in growth factor conditions greatly influenced the cellular doubling time in vitro. Corresponding changes in radiation sensitivity were minor for doses relevant for radiation therapy.
authors.affiliation: Department of Oncology, St. Olavs Hospital, University Hospital of Trondheim, 7006 Trondheim, Norway. anne.marthinsen@rit.no
authors.forename: Anne Beate
authors.initials: AB
authors.lastname: Langeland Marthinsen
authors.forename: Anne
authors.initials: A
authors.lastname: Dybdahl Wanderås
authors.forename: Steinar
authors.initials: S
authors.lastname: Lundgren
authors.forename: Trond
authors.initials: T
authors.lastname: Strickert
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Hundal
authors.forename: Bjørn Anton
authors.initials: BA
authors.lastname: Graff
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000532:radiotherapy; D002453:Cell Cycle / Q000187:drug effects / Q000528:radiation effects*; D002455:Cell Division / Q000187:drug effects / Q000528:radiation effects*; D017077:Culture Media, Conditioned; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D011829:Radiation Dosage; D011836:Radiation Tolerance; D016211:Transforming Growth Factor alpha / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000528:radiation effects*
chemical_list: D017077:Culture Media, Conditioned; D016211:Transforming Growth Factor alpha; D016212:Transforming Growth Factor beta; D007334:Insulin-Like Growth Factor I