Table 1.

Cytotoxicity of EpCAM-targeted immunoliposomes (SIL-Dox), nontargeted liposomes (SL-Dox), and free doxorubicin against EpCAM-positive (MCF-7 and SW2) and EpCAM-negative (RL) tumor cells

Cell lineFormulationIC50 (μmol/L)*
2 h24 h
MCF-7Free doxorubicin0.6 ± 0.20.15 ± 0.1
SIL-Dox (anti-EpCAM)15 ± 35 ± 1
SL-Dox (nontargeted)>17555 ± 10
SW2Free doxorubicin5 ± 21.5 ± 0.5
SIL-Dox (anti-EpCAM)60 ± 1025 ± 5
SL-Dox (nontargeted)>17580 ± 10
RLFree doxorubicin9 ± 12 ± 1
SIL-Dox (anti-EpCAM)>175100 ± 10
SL-Dox (nontargeted)>175120 ± 10
  • * Cells were plated in 96-well culture plates and incubated with free doxorubicin or doxorubicin encapsulated in liposomes as described in Materials and Methods. Data are presented as mean IC50 ± SD (n = 3).

  • P < 0.001, compared with nontargeted SL-Dox (one-way ANOVA, Tukey's post test).