土槿乙酸增强9顺式维甲酸对白血病细胞生长的抑制作用

目的观察过氧化物酶体激活物活化受体γ (PPARγ)的配体土槿乙酸(PLAB)联合维甲类X受体α (RXRα)的配体9-顺式维甲酸(9-cis RA)对白血病细胞生长的影响。方法应用MTT 法检测细胞生长抑制率，流式细胞术和Hoechst33342/PI染色分析HL-60细胞凋亡及细胞周期变化，RT-PCR检测PPARγ和RXRα mRNA表达。结果HL-60细胞系上有PPARγ和RXRα的表达，经配体联合作用后能明显抑制细胞生长，呈剂量依赖关系；细胞出现明显凋亡形态学改变和亚G₁峰；PPARγ和RXRα mRNA表达明显增强。结论PLAB能显著增强9-cis RA对HL-60细胞的生长抑制作用，其机制与凋亡诱导效应有关。

Pseudolaric Acid B Enhances Inhibitory Effect of 9-cis Retinoic Acid on Growth of Human Leukemia Cells

Objective To study the effects of pseudolaric acid B (PLAB) combined with 9 cis retinoic acid (9-cis RA) on the growth inhibition of human leukemia cells. Methods Human leukemia cells of the line HL 60 were cultured and then divided into 4 groups: control group; 9 cis RA group(9 cis RA, a RXRα ligand, was added); PLAB group (PLAB, a PPARγ ligand, was added) and combination group（9-cis RA and PLAB，were both added）. 96 h later the cell growth inhibition rate was detected by MTT assay. Flow cytometry and Hoechst33342/PI staining were used to detect the cell cycle and apoptosis. RT-PCR was used to detect the mRNA expression of RXRα and PPARγ. Results PPARγ and RXRα were expressed in HL 60 cell line. The cell proliferation was inhibited by PLAB combined with 9-cis RA in dose dependently manner. HL 60 cells exhibited typical apoptotic morphological alteration and sub G1 peak. PLAB combined with 9 cis RA significantly enhanced the mRNA expression of RXRα and PPARγ. Conclusion PLAB enhances the growth inhibitiory effect of 9-cis RA on human leukemia cells by the mechanism of induction of apoptosis.