Retinoic acid-resistant HL-60R cells harbor a point mutation in the retinoic acid receptor ligand-binding domain that confers dominant negative activity.
Retinoic acid-resistant HL-60R cells harbor a point mutation in the retinoic acid receptor ligand-binding domain that confers dominant negative activity.
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DOI：
10.1182/blood.v80.8.1885.1885
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发表时间：
1992-10
期刊：
影响因子：
20.3
通讯作者：
K. Robertson;B. Emami;S. Collins
中科院分区：
文献类型：
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作者：
K. Robertson;B. Emami;S. Collins
维甲酸（RA）诱导急性早幼粒细胞白血病（APL）细胞的粒细胞分化，是一种有用的治疗药物，用于这种疾病的患者。在HL-60早幼粒细胞白血病细胞系中，RA诱导的粒细胞分化似乎是通过RA受体（RAR-α）直接介导的。我们以前已经确定了HL-60（指定HL-60 R）的突变亚克隆，表现出相对抵抗RA和窝藏RA受体与RA的亲和力显着降低。在本研究中，我们已经确定了这种异常RA受体活性的遗传基础。聚合酶链反应扩增的cDNA产物对应于RAR-α配体结合结构域的DNA测序显示，在该突变型HL-60 R亚克隆中，RAR-α密码子411存在点突变。这种特定的C->T突变产生一个终止密码子，导致RAR-α的COOH末端截短52个氨基酸。在共转染研究中，携带这种突变的RAR-α的表达载体相对于正常RAR-α的反式激活功能表现出显性负活性。虽然我们的观察仅限于HL-60细胞，但类似的RA受体突变可能在RA治疗的APL患者获得RA耐药中起重要作用。
Retinoic acid (RA) induces granulocytic differentiation of acute promyelocytic leukemia (APL) cells and is a useful therapeutic agent for patients with this disease. In the HL-60 promyelocytic leukemia cell line, this RA-induced granulocytic differentiation appears to be directly mediated through the RA receptor (RAR-alpha). We have previously identified a mutant subclone of HL-60 (designated HL-60R) that exhibits relative resistance to RA and that harbors RA receptors with markedly reduced affinity for RA. In the present study, we have now identified the genetic basis for this aberrant RA receptor activity. DNA sequencing of polymerase chain reaction-amplified cDNA products corresponding to the RAR-alpha ligand-binding domain shows a point mutation in RAR-alpha codon 411 in this mutant HL-60R subclone. This specific C-->T mutation generates a termination codon resulting in the truncation of 52 amino acids at the COOH terminal end of RAR-alpha. In cotransfection studies, expression vectors harboring this mutated RAR-alpha exhibit dominant negative activity with respect to the trans-activating function of the normal RAR-alpha. Although our observations are limited to HL-60 cells, similar RA receptor mutations might play an important role in the acquisition of RA resistance in RA-treated APL patients.