survivin在儿童急性白血病细胞中的定位表达及与化疗的关系

Expression of survivin and its location in bone marrow cells of childhood acute leukemia: relationship to therapeutic efficacy

摘要:

目的：探讨survivin在急性白血病中的表达、细胞中的定位及与临床疗效的关系,并从细胞水平说明survivin定位表达与化疗疗效的关系。方法：应用免疫组织化学链霉亲和素、生物素、过氧化物酶复合物方法,检测62例急性白血病患儿和40例同期住院患儿(排除急性白血病)骨髓细胞survivin的表达,survivin在细胞中的定位。同时用SABC法检测不同浓度柔红霉素作用的Molt-4细胞中survivin定位表达的变化,用流式细胞术检测细胞凋亡率。结果：在62例急性白血病患儿中,survivin蛋白表达阳性率为41.9%(26/62),明显高于非急性白血病骨髓5.0%(2/40)(χ2=16.66,P<0.01);survivin在胞浆中的表达为46.2%(12/26),在胞核中的表达为53.9%(14/26),差异无统计学意义(χ2=0.3077,P>0.05),但二者第19天缓解率差异有显著性(P<0.05),sur-vivin胞核表达阳性者缓解率高于胞浆阳性表达者。DNR处理的Molt-4细胞survivin表达降低,呈时间和剂量依赖性,而且survivin从胞浆移位到胞核,流式细胞术显示细胞凋亡率也呈剂量和时间依赖性。结论：①survivin在儿童急性白血病中表达率为41.9%,提示其在儿童急性白血病发生、发展和预后中的意义;②survivin在胞浆和胞核的不同表达与临床化疗疗效有关,可作为判断预后的指标;③DNR可以降低白血病细胞中survivin表达,并使其从胞浆移位到胞核,诱导细胞凋亡。

Abstract:

OBJECTIVE: Survivin,a unique member of the inhibitor of apoptosis protein(IAP) family, plays an important role in regulating both apoptosis and cell division. Overexpression of survivin is associated with increased risk of recurrence and poor outcome in cancer patients. This study aimed to investigate the expression of survivin and its location as well as the relationship between cellular location and expression of surrivin and the therapeutic efficacy at the cellular level. ETHODS: The expression of survivin protein was deuected by immunohistochemical assay in bone marrow cells from 62 children with acute leukemia and 40 hospitalized children did not have leukemia (Control group), and in a human acute T lymphocytic leukemia cell line(Molt-4 cells) treated in vitro with daunorubicin(DNR). Cell apoptosis was detected using flow cytometry. RESULTS: Survivin protein was expressed in 41.9% of the 62 children with acute leukemia but in only 5.0% of the Control group(χ~2=16.66; P <0.01). The expression rate of survivin was 46.2% in cytoplasm and 53.9% in nucleus in the children with acute leukemia(χ~2=0.3077; P>0.05). However, the remission rate of patients in whom survivin expression was seen in the nucleus was significantly higher than that in patients in whom survivin was expressed in cytoplasm after chemotherapy. The survivin expression in Molt-4 cells decreased remarkably by DNR treatment in a time and dosage-dependent manner. DNR treatment also induced survivin transllocation from cytoplasm to nucleus and cell apoptosis in a time and dosage-dependent manner. CONCLUSIONS: Survivin may play an important role in the development and prognosis of childhood acute leukemia. The different expression pattern of survivin in the cytoplasm and the nucleus may be associated with therapeutic efficacy and prognosis in acute leukemia. DNR may reduce the survivin expression in leukemic cells and induce cell apoptosis.