多种化疗药对凋亡抑制蛋白Survivin在HL-60细胞中表达的影响

Survivin基因是细胞凋亡抑制蛋白家族的新成员，由于其具有在人类正常组织不表达而在各种肿瘤组织高表达的特性，因此有望成为肿瘤治疗的选择性靶点；有研究还表明survivin的表达与耐药性的发生有关。本研究旨在通过查明HL-60细胞在多种化疗药物作用后mRNA和蛋白的改变，初步探讨survivin和耐药性之间的关系。用合适浓度的柔红霉素（DNR）、米托蒽醌（MIT）和三氧化二砷（As2O3）作用于HL-60细胞，随后用RT-PCR检测给药的第1天和第3天HL-60细胞中survivin mRNA的表达情况，用Western blot检测survivin蛋白的表达情况。结果表明：在给予化疗药的第1天3组HL-60细胞中survivin mRNA表达水平全部降低，其中DNR组下降了10％，MIT组下降40％（P〈0．01），As2O3组下降了25％（P〈0．01）。在给予化疗药的第3天，DNR和MTT组的HL-60细胞中survivin mRNA表达较第1天有明显的升高，分别上升20％（P〈0．05）和65％（P〈0．01）；但给予As2O3组中的survivin mRNA表达仍持续降低，仅为第1天的68％（P〈0．01）。Western blot检测发现，给予DNR和MIT3天后的HL-60细胞中survivin蛋白含量分别升高了14％和11％，而给予As2O3组则下降了82％。结论：在给予化疗药后白血病细胞survivin表达先降低后升高的现象可能与化疗中耐药性的发生有关，而三氧化二砷有着不同的作用机制，这在逆转耐药性上可能发挥重要的作用。

Alteration of Expression of Survivin in HL-60 Cells Treated with Chemotherapeutic Drugs

Survivin, a new member of the inhibitor of apoptosis protein (IAP) family, expressed in the most human cancers but not in terminally differentiated adult tissues, so survivin may be a target for tumor therapy. In addition, some scholars found that survivin expression is associated with the resistance in chemotherapy. To explore the relationship between survivin and drug-resistance, the alteration of survivin mRNA and protein of HL-60 cells treated with daunomycin (DNR), mitoxantrone (MIT) and arsenic trioxide (As_2O_3) was investigated, the expressions of survivin mRNA and survivin protein were detected on the first and third day by RT-PCR and Western blot, respectively. The results showed that survivin mRNA levels all decreased after the first day of treatment with drugs. It was decreased by 10% in DNR group, 40% (P<0.01) in MIT group, and 25% (P<0.01) in As_2O_3 group in comparison with control cells. In the third day, the survivin mRNA treated with DNR was up-regulated by 20% (P<0.05), compared with the first day, and MIT was up-regulated by 65% (P<0.01), but As_2O_3 was still down-regulated by 32% (P<0.01). In Western blot, survivin protein level increased 14% after treated with DNR for three days, compared with the control cells, and 11% in MIT, but decreased by 82% in As_2O_3. It is concluded that after treatment with chemotherapeutic drugs, the survivin level descended at first day and then ascended obviously. This phenomenon may be associated with the resistance in chemotherapy for leukemia. On the other hand, As_2O_3 shows a different mechanism that may play a significant role to reverse resistance.