Different administration strategies with paclitaxel induce distinct phenotypes of multidrug resistance in breast cancer cells.

Both dose-dense and dose-escalation chemotherapy are administered in clinic. By approximately imitating the schedules of dose-dense and dose-escalation administration with paclitaxel, two novel multidrug resistant (MDR) cell lines Bads-200 and Bats-72 were successfully developed from drug-sensitive breast cancer cell line BCap37, respectively. Different from Bads-200, Bats-72 exhibited stable MDR and significantly enhanced migratory and invasive properties, indicating that they represented two different MDR phenotypes. Our results showed that distinct phenotypes of MDR could be induced by altered administration strategies with a same drug. Administrating paclitaxel in conventional dose-escalation schedule might induce recrudescent tumor cells with stable MDR and increased metastatic capacity.