title: Prevalidation of the rat CFU-GM assay for in vitro toxicology applications.
abstract: In vitro haematotoxicity assays are thought to have the potential to significantly reduce and refine the use of animals for haematotoxicity testing. These assays are used successfully in all types of studies - however, their use is not so common in human toxicology studies in the preclinical setting, as they are not required for regulatory testing in this case. Furthermore, these assays could play a key role in bridging the gap between preclinical toxicology studies in animal models and clinical investigations. In previous studies, the Colony Forming Unit-Granulocyte Macrophage (CFU-GM) assay has been validated for testing drug haematotoxicity (with both mouse bone-marrow and human cord blood) and for predicting the in vivo human maximal tolerated dose (MTD) by adjusting in vivo data on mouse toxicity. Recently, a Colony Forming Unit-Megakaryocyte (CFU-MK) assay has also been prevalidated for testing drug toxicity toward megakaryocytes. The rat CFU-GM assay has been used by many researchers for its ability to evaluate in vitro haematotoxicity. Although it is not yet available, a standardised procedure for data comparison could be very important, since the rat is the most widely-used species for the in vivo testing of toxicants. This report presents the results of the prevalidation study developed to analyse the intra-laboratory and inter-laboratory variability of a standardised operating procedure for this assay and its performance for the in vitro determination of the inhibitory concentration (IC) values of drugs on rat myeloid progenitors (CFU-GM). The results demonstrate that the CFU-GM assay can be performed with cryopreserved rat bone-marrow cells (rBMC). The assay represents a useful tool for evaluating the toxicity of a compound, in terms of both relative toxicity (when different molecules are compared) and the prediction of the degree of in vivo toxicity. The use of this assay could greatly reduce the number of rats used in experimental procedures, and could also contribute to the accumulation of more toxicity data on compounds to be registered according to the criteria established by the European Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) programme.
authors.affiliation: Department of Public Health, Microbiology, Virology, University of Milan, Italy. augusto.pessina@unimi.it
authors.forename: Augusto
authors.initials: A
authors.lastname: Pessina
authors.forename: Arianna
authors.initials: A
authors.lastname: Bonomi
authors.forename: Loredana
authors.initials: L
authors.lastname: Cavicchini
authors.forename: Beatriz
authors.initials: B
authors.lastname: Albella
authors.forename: Laura
authors.initials: L
authors.lastname: Cerrato
authors.forename: Dominique
authors.initials: D
authors.lastname: Parent-Massin
authors.forename: Yann
authors.initials: Y
authors.lastname: Sibiril
authors.forename: Ralph
authors.initials: R
authors.lastname: Parchment
authors.forename: Holger
authors.initials: H
authors.lastname: Behrsing
authors.forename: Paolo
authors.initials: P
authors.lastname: Verderio
authors.forename: Sara
authors.initials: S
authors.lastname: Pizzamiglio
authors.forename: Manuela
authors.initials: M
authors.lastname: Giangreco
authors.forename: Carolina
authors.initials: C
authors.lastname: Baglio
authors.forename: Valentina
authors.initials: V
authors.lastname: Coccè
authors.forename: Francesca
authors.initials: F
authors.lastname: Sisto
authors.forename: Laura
authors.initials: L
authors.lastname: Gribaldo
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000633:toxicity; D000970:Antineoplastic Agents / Q000627:therapeutic use / Q000633:toxicity; D016026:Bone Marrow Transplantation / Q000009:adverse effects; D003114:Colony-Forming Units Assay / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007213:Indomethacin / Q000627:therapeutic use / Q000633:toxicity; D007928:Lethal Dose 50; D008264:Macrophages / Q000502:physiology; D020714:Maximum Tolerated Dose; D051379:Mice; D051381:Rats; D014183:Transplantation, Heterologous / Q000009:adverse effects
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000970:Antineoplastic Agents; D007213:Indomethacin