粒系集落刺激因子对急性髓系白血病原代细胞mdr1基因表达的调节作用

Effect of Granulocyte Colony Stimulating Factor on Modulation of mdr 1 Gene Expression in Primary Cells of Human Acute Myeloblastic Leukemia

研究多药耐药基因(mdr 1)与急性髓系白血病(AML)细胞分化之间的关系。采用常规分离白血病细胞,体外培养7天,然后通过形态学、细胞化学、细胞功能(NBT)、细胞免疫化学(APAAP)和逆转录.聚合酶链反应(RT-PCR)及MTT技术观察了细胞分化和mdr1表达变化以及AML细胞对柔红霉素敏感性反应。结果表明,AML细胞分化成熟后mdr1表达水平下降,并且随mdr1水平下降,AML细胞对柔红霉素敏感性增加。结论提示,AML细胞分化与mdr1之间有密切的内在联系,利用分化诱导剂粒系集落刺激因子从基因水平逆转白血病耐药是一种行之有效的方法。

To study the relationship between differentiation of AML cells and mdr 1 gene expression, specimens from 31 patients with acute myeloblaslic leukemia (AML) were cultured in vitro with or without G-CSF for 7 days and then examined by Wright-Giemsa staining, cytochemistry( naphthyl-ASD-chloroacetate esterase, a-naphthy -acetate esterase) and nitroblue tetrazolium reduction. The expression of CD11b, CD13, CD14, CD15, CD33 and CD34 membrane antigens was also evaluated by immunocytochemical staining. Meanwhile, expression of mdr 1 gene and the sensitivity of AML cells to daunorubicin have been determined respectively by polymerase chain reaction and MTT assay. The cells from 15 of the 31 cases showed maturation by comparative analysis of the above panel of parameters and also expression of mdr 1 gene has been observed in 13 specimens from 31 AML patients. After G-CSF treatment, a decrease of mdr 1 expresion was observed in cells from 6 of the 8 patients in differentiated groups and 2 of the 5 patients in undifferentiated group. The difference in downregulation of mdr 1 mRNA between the differentiated group and group before culture was significant ( P < 0.05 ) . Further, MTT assays revealed a concomitant decrease of daunorubicin IC50 with a decline of the mdr 1 mRNA. These results demonstrated that the expression of mdr 1 gene could be in close relation to differentiation of AML cells, it may be a effective means in reversing drug resistance through inducing differentiation of AML cells.