title: Short and long-term exposure of CNS cell lines to BPA-f a radiosensitizer for boron neutron capture therapy: safety dose evaluation by a battery of cytotoxicity tests.
abstract: Despite the current clinical use of boronophenylalanine-fructose (BPA-f), as radiosensitizer, in BNCT application for brain tumors, still remains to be determined the safety dose of this agent. We evaluated the potential risk of primary BPA-f toxicity before neutronic irradiation at different concentrations (0-100μgBeq/ml) after short- and long-term exposure (4-48h and 7-10 days), using a battery of tests (i.e. MTT assay, calcein-AM/Propidium Iodide staining, clonogenic test) in CNS cell models (D384 and SH-SY5Y), and non-neuronal primary human fibroblasts (F26). MTT data showed: (i) no cytotoxic effects after short-term exposure (4h) to any of BPA-f concentrations tested in all cell models; (ii) dose- and time-dependent mitochondrial activity impairment in D384 and SH-SY5Y cells only (with 60% and 40% cell death in D384 and SH-SY5Y, respectively, after 48h exposure to BPA-f 100μgBeq/ml). By Calcein-AM/PI staining, BPA-f treatment was specific toward SH-SY5Y cells only: a dose-dependent cell density reduction was observed, with a more pronounced effect after 48h exposure (15-40% at doses ranging 20-100μgBeq/ml). Clonogenic data revealed dose-dependent decrease of cell proliferative capacity in all cell lines, still the SH-SY5Y cells were the most sensitive ones: the lowest dose (20μgBeq/ml) produced 90% cell decrease. These results indicate dose- and time-dependent cytotoxic effects of BPA-f, with CNS cells showing a lower tolerance compared to fibroblasts. Long-term exposure to BPA-f compromised the proliferative capacity regardless of cell model type (cell sensitivity being SH-SY5Y>D384>F26). In short-time exposure, BPA-f exhibits a safe dosage up to 40μgBeq/ml for the viability of CNS cell lines.
authors.affiliation: Salvatore Maugeri Foundation IRCCS Institute of Pavia, and University of Pavia, Toxicology Division and European Centre for Nanomedicine, 27100 Pavia, Italy. uliana.desimone@unipv.it
authors.forename: U
authors.initials: U
authors.lastname: De Simone
authors.forename: L
authors.initials: L
authors.lastname: Manzo
authors.forename: C
authors.initials: C
authors.lastname: Ferrari
authors.forename: J
authors.initials: J
authors.lastname: Bakeine
authors.forename: C
authors.initials: C
authors.lastname: Locatelli
authors.forename: T
authors.initials: T
authors.lastname: Coccini
mesh_terms: D001896:Boron Compounds / Q000633:toxicity*; D016754:Boron Neutron Capture Therapy / Q000379:methods*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000187:drug effects* / Q000473:pathology; D005632:Fructose / Q000031:analogs & derivatives* / Q000633:toxicity; D006801:Humans; D008928:Mitochondria / Q000187:drug effects / Q000473:pathology; D009474:Neurons / Q000187:drug effects* / Q000473:pathology; D011838:Radiation-Sensitizing Agents / Q000633:toxicity*; D018570:Risk Assessment; D013997:Time Factors; D018675:Toxicity Tests
chemical_list: C089739:4-boronophenylalanine-fructose; D001896:Boron Compounds; D011838:Radiation-Sensitizing Agents; D005632:Fructose