Estrogen Response element-GFP (ERE-GFP) introduced MCF-7 cells demonstrated the coexistence of multiple estrogen-deprivation resistant mechanisms
Estrogen Response element-GFP (ERE-GFP) introduced MCF-7 cells demonstrated the coexistence of multiple estrogen-deprivation resistant mechanisms
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DOI：
10.1016/j.jsbmb.2013.08.012
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发表时间：
2014-01-01
影响因子：
4.1
通讯作者：
Hayashi, Shin-ichi
中科院分区：
文献类型：
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作者：
Fujiki, Natsu;Konno, Hiromi;Hayashi, Shin-ichi
雌激素剥夺抗性和雌激素受体（ER）信号独立性在ER阳性乳腺癌中的获得是推进乳腺癌侵袭性的关键步骤之一;然而，这尚未详细阐明。为了解决这个问题，我们建立了几个雌激素剥夺耐药（EDR）乳腺癌细胞系，从我们独特的MCF-7细胞，这已经稳定转染的ERE-GFP报告质粒。通过检测活细胞中GFP的表达，从细胞克隆中建立了3个具有高ER活性的细胞系和另外3个不具有ER活性的细胞系。前三种ERE-GFP阳性的EDR细胞系均显示ER过表达和多种ER靶基因的高表达。细胞内信号传导因子的进一步分析显示，通过先前报道的类似机制，ER α在Ser 167和Akt在Thr 308上的磷酸化状态发生了显著变化;然而，我们没有发现MAP激酶因子的任何变化。磷酸化蛋白质组学分析也表明Akt通路可能参与ER α的磷酸化。另一方面，在ERE-GFP阴性的EDR细胞中观察到c-Jun N-末端激酶（JNK）的组成性激活，并且这些细胞的生长被JNK抑制剂抑制。IGF 1 R特异性抑制剂减少了JNK的磷酸化，这表明一种新的信号通路IGF 1 R-JNK可能对ER非依赖性MCF-7细胞的增殖很重要。这些结果表明，ER阳性乳腺癌细胞可以同时通过两种以上的机制获得耐药性，这表明多种机制可能同时发生。这一发现也意味着具有不同耐药机制的乳腺癌可以在个体患者中同时发生和混合，并且可能是癌症复发的原因。(C)2013爱思唯尔有限公司保留所有权利。
The acquisition of estrogen-deprivation resistance and estrogen receptor (ER) signal-independence in ER-positive breast cancer is one of the crucial steps in advancing the aggressiveness of breast cancer; however, this has not yet been elucidated in detail. To address this issue, we established several estrogen-deprivation-resistant (EDR) breast cancer cell lines from our unique MCF-7 cells, which had been stably transfected with an ERE-GFP reporter plasmid. Three cell lines with high ER activity and another 3 cell lines with no ER activity were established from cell cloning by monitoring GFP expression in living cells. The former three ERE-GFP-positive EDR cell lines showed the overexpression of ER and high expression of several ER-target genes. Further analysis of intracellular signaling factors revealed a marked change in the phosphorylation status of ER alpha on Ser167 and Akt on Thr308 by similar mechanisms reported previously; however, we could not find any changes in MAP-kinase factors. Comprehensive phosphoproteomic analysis also indicated the possible contribution of the Akt pathway to the phosphorylation of ERa.On the other hand, constitutive activation of c-Jun N-terminal kinase (INK) was observed in ERE-GFP-negative EDR cells, and the growth of these cells was inhibited by a JNK inhibitor. An IGF1R-specific inhibitor diminished the phosphorylation of JNK, which suggested that a novel signaling pathway, IGF1R-JNK, may be important for the proliferation of ER-independent MCF-7 cells. These results indicate that ER-positive breast cancer cells can acquire resistance by more than two mechanisms at a time, which suggests that multiple mechanisms may occur simultaneously. This finding also implies that breast cancers with different resistance mechanisms can concomitantly occur and mingle in an individual patient, and may be a cause of the recurrence of cancer. (C) 2013 Elsevier Ltd. All rights reserved.