Weekly administration of paclitaxel induces long-term aneugenicity in nude mice

Abstract

We investigated the potential in vivo aneugenic effects associated with paclitaxel treatment. For this purpose, we treated female nude mice with paclitaxel using doses equivalent to those used in weekly schedules at the clinical level (three cycles of 30 mg/kg/week for 3 consecutive weeks followed by 1 resting week). We then evaluated the frequencies of micronucleated erythrocytes (MNE) in peripheral blood using the acridine orange micronucleus assay. The frequency of MNE was evaluated after 24 h and 168 h of administration of the last dose of each paclitaxel cycle (STA mice group) as well as after one year of the first dose of treatment (LTA mice group). We also analyzed the cytology of peripheral blood and bone marrows obtained from these mice at each time period. In the STA mice group, 3 cycles of paclitaxel induced a 2.4-fold increase in MNE frequencies compared to the control group (P