title: Growth delay in small EMT6 spheroids induced by cytotoxic drugs and its modification by misonidazole pretreatment under hypoxic conditions.
abstract: Experiments have been carried out to determine whether the growth delay induced in small EMT6 spheroids (approximately 250 micrometers in diameter) by a range of cytotoxic drugs can be increased by pre-incubation of the spheroids under hypoxic conditions with misonidazole (MISO). Hypoxic pre-incubation was for 3 or 5 h in the presence of 5 mM MISO, and caused a growth delay of about 1 day or 2 days respectively. Sensitization to nitrogen mustard (HN2), melphalan, chlorambucil, BCNU and CCNU was seen, but the shapes of the dose-response curves and the ratio of effects for 3 h and 5 h pretreatment varied between the drugs. In contrast to the other agents, hypoxic pre-incubation with MISO reduced the spheroid response to adriamycin.
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D051379:Mice; D008920:Misonidazole / Q000494:pharmacology; D009374:Neoplasms, Experimental / Q000473:pathology*; D010100:Oxygen / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000970:Antineoplastic Agents; D008920:Misonidazole; D010100:Oxygen