靶向CD123的重组白细胞介素-3-力达霉素融合蛋白对白血病M07e细胞的杀伤机制

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

目的 研究白细胞介素-3-力达霉素（IL-3-LDM）融合蛋白靶向杀伤CD＋123 肿瘤细胞的作用机制。方法 用CCK-8检测IL-3-LDM融合蛋白靶向杀伤人类原巨核细胞白血病MO7e细胞的作用，用IC20浓度的IL-3-LDM及LDM分别与MO7e靶细胞培养后，利用AnnexinV-FITC及碘化丙啶（PI）染色经流式细胞分选术检测分析细胞凋亡率和周期分布变化。结果 LDM、IL-3-LDM对MO7e细胞的IC50分别为116、50 pmol／L。经IC20浓度的IL-3-LDM（12 pmol／L）融合蛋白与LDM（30 pmol／L）分别处理MO7e细胞后，在24、48、72 h分别检测到细胞凋亡率呈逐渐上升趋势（IL-3-LDM组分别为26.1 %、59.3 %和62.1 %，LDM组分别为34.4 %、43.3 %和55.2 %），且细胞在处理48和72 h后出现明显的G2／M期阻滞现象，与没有靶向的LDM药物作用机制一致。结论 IL-3-LDM融合蛋白作用机制与LDM一致，通过引起细胞G2／M期阻滞导致细胞凋亡进而死亡，证明IL-3靶向作用及其携带的高效药物LDM杀伤作用的有效性。

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.