Response and resistance to retinoic acid are mediated through the retinoic acid nuclear receptor gamma in human teratocarcinomas.
Response and resistance to retinoic acid are mediated through the retinoic acid nuclear receptor gamma in human teratocarcinomas.
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发表时间：
1994-03
期刊：
影响因子：
8
通讯作者：
M. Moasser;A. Deblasio;E. Dmitrovsky
中科院分区：
文献类型：
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作者：
M. Moasser;A. Deblasio;E. Dmitrovsky
全反式维甲酸（RA）处理多能性人畸胎瘤（TC）细胞系NTERA-2克隆D1（缩写为NT 2/D1）诱导神经元表型。与未处理的NT 2/D1细胞相比，RA处理的细胞具有降低的增殖潜力。为了确定视黄酸受体（RAR）是直接链接到RA在这些细胞中的反应，9 RA抗性亚克隆的衍生和表征。与亲本NT 2/D1细胞不同，所有这些亚克隆和从头RA抗性人TC细胞系N2102 Ep克隆2AG（缩写为N2102 ep）表现出降低的RAR γ表达。通过Southern分析和克隆的RAR γ cDNA的转录特性，在NT 2/D1细胞和称为NT 2/D1-R1的代表性RA抗性NT 2/D1亚克隆内研究RAR γ基因。未发现这些RAR γ物质之间的结构或功能差异，表明RA抗性是由于NT 2/D1-R1细胞中表达的RAR γ水平降低所致。为了探索这种可能性，将RAR γ cDNA稳定转染到NT 2/D1-R1细胞中。该cDNA的表达部分恢复了NT 2/D1-R1细胞对RA的反应。RAR γ在亲本NT 2/D1细胞中的作用在瞬时转染测定中使用FGF 4启动子-增强子报告基因构建体进行研究，所述FGF 4启动子-增强子报告基因构建体在未分化但在分化的TC细胞中没有转录活性。表达的RAR γ cDNA与该报告基因的剂量依赖性共转染在RA存在下比不表达RAR γ的报告基因的转染更有效地抑制其转录活性。共转染也降低了报告活性的情况下，外源添加的配体。总之，这些发现揭示了RAR γ表达与人TC细胞中的RA反应和抗性紧密相关。这些数据暗示了RAR γ在RA介导的这些TC分化中的重要作用。
All-trans-retinoic acid (RA) treatment of the multipotent human teratocarcinoma (TC) cell line NTERA-2 clone D1 (abbreviated NT2/D1) induces a neuronal phenotype. Compared to untreated NT2/D1 cells, RA treated cells have reduced proliferative potential. To identify which retinoic acid receptor (RAR) is directly linked to RA response in these cells, nine RA resistant subclones were derived and characterized. Unlike parental NT2/D1 cells, all these subclones and a de novo RA resistant human TC cell line, N2102Ep clone 2AG (abbreviated N2102ep), exhibited reduced RAR gamma expression. The RAR gamma gene was studied within NT2/D1 cells and a representative RA resistant NT2/D1 subclone called NT2/D1-R1 by Southern analysis and by the transcriptional properties of cloned RAR gamma cDNAs. No structural or functional differences between these RAR gamma species were found suggesting that RA resistance is due to reduced levels of RAR gamma expressed in NT2/D1-R1 cells. To explore this possibility an RAR gamma cDNA was stably transfected into NT2/D1-R1 cells. Expression of this cDNA partially restored the response to RA in NT2/D1-R1 cells. The role of RAR gamma in parental NT2/D1 cells was studied in transient transfection assays using an FGF4 promoter-enhancer reporter construct that is transcriptionally active in undifferentiated but not in differentiated TC cells. The dose dependent co-transfection of an expressed RAR gamma cDNA with this reporter more efficiently repressed its transcriptional activity in the presence of RA than transfection of the reporter without expressed RAR gamma. Co-transfection also decreased reporter activity in the absence of exogenously added ligand. Together, these findings reveal that RAR gamma expression is tightly coupled to RA response and resistance in human TC cells. These data implicate an important role for RAR gamma in the RA-mediated differentiation of these TCs.