Van Roozendaal K E, Darling D, Farzaneh F
Molecular Medicine Unit, King's College School of Medicine and Dentistry, Denmark Hill, London.
Exp Cell Res. 1990 Sep;190(1):137-40. doi: 10.1016/0014-4827(90)90155-4.
The expression of c-myc and two calcium-binding proteins, MRP8 and MRP14, has been analyzed in wild-type and differentiation-resistant HL-60 variants. In HL-R5 cells, resistant to the induction of differentiation by retinoic acid but not DMSO, the characteristic c-myc down-regulation which is associated with HL-60 differentiation, as well as increased levels of MRP8 and MRP14, is detectable only after DMSO treatment. By contrast HL-D4 cells, which were selected for resistance to the induction of differentiation by DMSO alone, are actually resistant to both DMSO and retinoic acid. However, treatment of HL-D4 cells with DMSO results in a transient c-myc down-regulation in the absence of either growth arrest or induction of differentiation. Neither agent can induce an increase in the level of either MRP8 or MRP14 in HL-D4. The resistance of HL-D4 cells to DMSO and retinoic acid, and the different effects of these agents on c-myc RNA levels, despite their common effect on the expression of MRP8 and MRP14, suggest that the two agents act through different pathways which coverage before the onset of myeloid differentiation in HL-60 cells.
已在野生型和抗分化的HL-60变体中分析了c-myc以及两种钙结合蛋白MRP8和MRP14的表达情况。在HL-R5细胞中，其对维甲酸诱导的分化有抗性，但对二甲基亚砜（DMSO）诱导的分化无抗性，只有在DMSO处理后才能检测到与HL-60分化相关的c-myc特征性下调以及MRP8和MRP14水平的升高。相比之下，仅被选择为对DMSO诱导的分化有抗性的HL-D4细胞，实际上对DMSO和维甲酸都有抗性。然而，用DMSO处理HL-D4细胞会导致在没有生长停滞或分化诱导的情况下c-myc短暂下调。两种试剂都不能诱导HL-D4中MRP8或MRP14水平的增加。HL-D4细胞对DMSO和维甲酸的抗性，以及这些试剂对c-myc RNA水平的不同影响，尽管它们对MRP8和MRP14的表达有共同影响，但表明这两种试剂通过不同的途径起作用，这些途径在HL-60细胞髓系分化开始之前就已汇合。
