Figure 2.

Role of PS Expressed on the Surface of Tumor Cells in Antitumor Activity of PC-SA Liposomes

(A–D) Treatment of annexin V-preincubated (A) B16F10, (B) K562, (C) rat C6 glioma, and (D) U937 cells with graded dose of PC-SA liposomes, showing a reversal in killing activity in comparison with cells that were not pretreated with annexin V. (E–G) Blocking of PC-SA liposomes by anti-PS antibodies. Treatment of anti-PS antibody-preincubated (E) B16F10, (F) K562, and (G) U937 cells with graded doses of PC-SA liposomes, showing a reversal in killing activity in comparison with cells that were not pretreated with the antibodies. (H) Effect of the activity of a 7:2 molar ratio of PC-SA liposomes (120 μg/mL with respect to PC) after blocking it with different doses of PC-PS liposomes (7:2). All data represent the mean of triplicate experiments, with error bars indicating the SEM.