Table 2

Persistence of MDR reversal in MCF-7/ADR and C-26 cells

ChemosensitizerTreatment protocolDoxorubicin IC50m)
Chemosensitizer washout*Time span between washout and doxorubicin addition (hours)C-26 cellsMCF-7/ADR cells
NoneNone0>19>30
15 μm VerapamilNone09.111.5
Yes0>19>30
5 μm FluoxetineNone00.290.84
Yes00.621.20
Yes61.251.45
Yes121.601.85
Yes241926
  • * Chemosensitizer washout: None indicates no washout. Yes indicates washout was performed according to the details described under Materials and Methods.

  • Zero hours indicates doxorubicin was added immediately after the prior step (whether washout was or was not performed) and 6,12, and 24 hours indicate the time span between termination of the washout (during which the system was incubated with serum-supplemented growth media alone) and doxorubicin addition.