环氧合酶-2抑制剂对白血病细胞HL-60的化疗增敏作用及机制

Effects of cyclooxygenase-2 inhibitor on doxorubiein chemosensitivity in leukemia HL-60 cell line

目的 观察环氧合酶-2（COX-2）抑制剂塞来昔布对白血病细胞株HL-60的化疗增敏作用，并对其机制进行初步探讨。方法MTT法评估塞来昔布j多柔比星及二者联合对HL．60细胞的生长抑制效应；流式细胞术（FCM）检测细胞的凋亡；反转录聚合酶链反应（RT—PCR）检测Survivin基因的表达；Western blotting检测Survivin蛋白的表达。结果多柔比星联合塞来昔布5和10μmol／L对HL-60细胞的半数抑制浓度（IC50）分别为0．25及0．16μg／ml，明显低于多柔比星单用的IC50（0．48／,μg／m1）；多柔比星0．10μg／ml联合10μm01／L塞来昔布下调survivin基因mRNA及蛋白的表达；联合塞来昔布5和10μmol／L的凋亡率[分别为（13．07±1．66）％及（22．36±1．84）％]较多柔比星0．10μg／ml单用[（5．72±1．25）％]明显增加（P〈0．01）。结论COX-2抑制剂塞来昔布对白血病细胞株HL-60具有明显的化疗增敏作用，其初步机制涉及下调Survivin的表达，增加细胞凋亡。

Objective To evaluate the enhancement of chemosensitivity of celecoxib, a specific cyclooxygenase-2 （COX-2） inhibitor, on leukemia HL-60 cell line in vitro, and explore the possible mechanisms. Methods MTF assay was used to assess the cytostatic efficacy of doxorubicin in the absent or present of different doses of celecoxib on HL-60 cell. The apoptosis of HL-60 ceils was measured by flow cytometry （FCM）. Gene expressions of Sutvivin was examined by reverse transcription-polymerase chain reaction （RT-PCR）. Protein of survivin was detected by Western blotting. Results Celecoxib could increase the cytostatic efficacy of doxorubicin on HL-60 cells. HL-60 ceils were treated with increasing doses of doxorubicin in absence or presence of celecoxib （5 μmol/L, 10 μmol/L）, IC50 were 0.48 μg/ml, 0.25 Ixg/ml and 0.16 μg/ml, respectively. Doxorubicin combined with low dose of celecoxib could induce the down-regulation of mRNA and protein of Survivin. Apoptosis rate of HL-60 cells treated with both 0.10 p,g/ml doxombicin and celecoxib（5 μmol/L, l0 /μmol/L） were （13.07±1.66） % and （22.36±1.84） %, respectively, while it was （5.72±1.25） % in HL-60 cells treated with 0.10 μg/ml doxorubicin alone, with significant difference （P 〈0.01）. Conclusion Celecoxib could enhance the chemosensitivity of doxorubicin on leukemia HL-60 cell, which involves in increasing the apoptosis of HL-60 cells by down-regulation expression of Survivin.