Retinoid X receptor α is highly phosphorylated in retinoic acid-resistant HL-60R cells and the combination of 9-cis retinoic acid plus MEK inhibitor induces apoptosis in the cells
- 作者：Nobuhiro Kanemura ; Hisashi Tsurumi ; Masataka Okuno ; Rie Matsushima-Nishiwaki ; Masahito Shimizu ; Hisataka Moriwaki
- 关键词：9-cis RA ; MEK inhibitor ; RXR
//www.sciencedirect.com/scidirimg/entities/204e.gif" alt="greek small letter alpha" title="greek small letter alpha" border="0"> ; Apoptosis ; HL-60 ; HL-60R
- 刊名：Leukemia Research
- 出版年：2008
- 期刊代码：186_01452126
- 类别：med
- 出版时间：June 2008
- 卷：32
- 期：6
- 页码：884-892
- 文件大小：676 K
摘要
We examined the effects of 9-cis retinoic acid (RA) on the expression levels of retinoid X receptor 
(RXR) and its phosphorylated form (p-RXR) in HL-60 and HL-60R cells. 9-cis RA reduced both RXR and p-RXR in HL-60 cells, but did neither in HL-60R cells. However, when the HL-60R cells were treated with the combination of 9-cis RA plus PD98059, MEK inhibitor, the p-RXR and RXR proteins all markedly decreased. Moreover, the combination of those agents induced apoptosis in HL-60R cells. Phosphorylation of RXR might be associated with RA-resistance in HL-60R cells.
(RXR) and its phosphorylated form (p-RXR) in HL-60 and HL-60R cells. 9-cis RA reduced both RXR and p-RXR in HL-60 cells, but did neither in HL-60R cells. However, when the HL-60R cells were treated with the combination of 9-cis RA plus PD98059, MEK inhibitor, the p-RXR and RXR proteins all markedly decreased. Moreover, the combination of those agents induced apoptosis in HL-60R cells. Phosphorylation of RXR might be associated with RA-resistance in HL-60R cells.