Mechanistic study of CD123 targeting by interleukin 3-lidamycin in human primary megakaryocytic leukemia MO7e cells

Objective To explore the mechanism of interleukin3-lidamycin （IL-3-LDM） anti-tumor effect on CD＋123 cells. Methods CCK-8 assay was performed to measure the IL-3-LDM anti-tumor effect. Apoptosis and cell cycle of MO7e cells were analyzed by flow cytometry when treated with the IC20 concentrations of IL3-LDM and LDM. Results The IC50 of LDM and IL-3-LDM were 116 pmol/L and 50 pmol/L, respectively. Mechanistic studies revealed that IL-3-LDM （IC20 12 pmol/L） treatment remarkably promoted apoptosis of MO7e cells （in 24 h, 48 h and 72 h were 26.1 %, 59.3 % and 62.1 %）, compared with LDM （IC20 30 pmol/L） （34.4 %, 43.3 %, 55.2 %）. This was accompanied by cell cycle arrest at G2/M after 48 h and 72 h and was time dependent. The results agreed with LDM used alone. Conclusion IL-3-LDM and LDM have the same killing mechanism and prove the effectiveness of IL-3 delivery system. Key words: Recombinant fusion proteins;  Lidamyein;  Interleukin-3;  Leukemia;  Cell cycle; Apoptosis