Gonadotropin-releasing hormone receptor activates GTPase RhoA and inhibits cell invasion in the breast cancer cell line MDA-MB-231.
Gonadotropin-releasing hormone receptor activates GTPase RhoA and inhibits cell invasion in the breast cancer cell line MDA-MB-231.
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DOI：
10.1186/1471-2407-12-550
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发表时间：
2012-11-23
期刊：
影响因子：
3.8
通讯作者：
Valdés J
中科院分区：
文献类型：
--
作者：
Aguilar-Rojas A;Huerta-Reyes M;Maya-Núñez G;Arechavaleta-Velásco F;Conn PM;Ulloa-Aguirre A;Valdés J
促性腺激素释放激素（GnRH）及其受体（GnRHR）在包括乳腺在内的许多恶性肿瘤中均有表达。在后一种情况下，两者都是有效的入侵抑制剂。然而，激活的GnRH/GnRHR系统发挥这种作用的信号通路尚未明确确立。在这项研究中，我们提供了实验证据，描述了GnRH抑制乳腺癌细胞侵袭的机制组成部分。在没有或存在GnRH激动剂的情况下，通过荧光法、流式细胞术分析和共聚焦显微镜，在表达野生型或突变型DesK191 GnRHR的高侵袭性细胞系MDA-MB-231中测量肌动蛋白聚合和底物粘附。在MDA-MB-231细胞中，共表达gnrrs和人p190Rho的GAP结构域GAP- a或显性负突变体GAP- y1284d，测量了RhoA-GTP对应力纤维形成和局灶黏附组装的影响。采用transwell迁移法测定细胞侵袭情况。激动剂刺激激活野生型GnRHR和瞬时转染MDA-MB-231细胞的高质膜表达突变体GnRHR- desk191，有利于f -肌动蛋白聚合和底物粘附。共聚焦成像允许检测f -肌动蛋白水平和暴露于GnRH促进的应力纤维增加之间的关联。下拉实验表明，对肌动蛋白细胞骨架的影响是由gnrh刺激的RhoA GTPase激活引起的。Transwell Chambers的实验显示，这种小G蛋白的激活有利于细胞对胶原- i的粘附和局灶粘附复合物数量的显著增加，从而抑制MDA-MB-231细胞的侵袭能力。我们在这里表明GnRH抑制高度侵袭性乳腺癌来源的MDA-MB-231细胞的侵袭。这种作用是通过RhoA GTPase的激活、应力纤维的形成和局灶性粘附促进底物粘附的增加而介导的。这些观察结果为激活过表达的gnrrs影响这种恶性细胞系的细胞侵袭潜力的分子机制提供了新的见解，并为设计基于机制的乳腺癌辅助治疗提供了机会。
Gonadotropin-releasing hormone (GnRH) and its receptor (GnRHR) are both expressed by a number of malignant tumors, including those of the breast. In the latter, both behave as potent inhibitors of invasion. Nevertheless, the signaling pathways whereby the activated GnRH/GnRHR system exerts this effect have not been clearly established. In this study, we provide experimental evidence that describes components of the mechanism(s) whereby GnRH inhibits breast cancer cell invasion. Actin polymerization and substrate adhesion was measured in the highly invasive cell line, MDA-MB-231 transiently expressing the wild-type or mutant DesK191 GnRHR by fluorometry, flow cytometric analysis, and confocal microscopy, in the absence or presence of GnRH agonist. The effect of RhoA-GTP on stress fiber formation and focal adhesion assembly was measured in MDA-MB-231 cells co-expressing the GnRHRs and the GAP domain of human p190Rho GAP-A or the dominant negative mutant GAP-Y1284D. Cell invasion was determined by the transwell migration assay. Agonist-stimulated activation of the wild-type GnRHR and the highly plasma membrane expressed mutant GnRHR-DesK191 transiently transfected to MDA-MB-231 cells, favored F-actin polymerization and substrate adhesion. Confocal imaging allowed detection of an association between F-actin levels and the increase in stress fibers promoted by exposure to GnRH. Pull-down assays showed that the effects observed on actin cytoskeleton resulted from GnRH-stimulated activation of RhoA GTPase. Activation of this small G protein favored the marked increase in both cell adhesion to Collagen-I and number of focal adhesion complexes leading to inhibition of the invasion capacity of MDA-MB-231 cells as disclosed by assays in Transwell Chambers. We here show that GnRH inhibits invasion of highly invasive breast cancer-derived MDA-MB-231 cells. This effect is mediated through an increase in substrate adhesion promoted by activation of RhoA GTPase and formation of stress fibers and focal adhesions. These observations offer new insights into the molecular mechanisms whereby activation of overexpressed GnRHRs affects cell invasion potential of this malignant cell line, and provide opportunities for designing mechanism-based adjuvant therapies for breast cancer.
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影响因子：
3.8
作者：
Kahán, Z;Nagy, A;Groot, K
通讯作者：
Groot, K
影响因子：
3.3
作者：
Arthur, WT;Burridge, K
通讯作者：
Burridge, K
影响因子：
50.5
作者：
Ferlay, J.;Autier, P.;Boyle, P.
通讯作者：
Boyle, P.
影响因子：
5.8
作者：
EIDNE, KA;FLANAGAN, CA;MILLAR, RP
通讯作者：
MILLAR, RP
培养的成纤维细胞中细胞肌肉和细胞 - 细胞接触部位的免疫电子显微镜研究。
DOI：
10.1083/jcb.95.1.205
发表时间：
1982-10
期刊：
The Journal of cell biology
影响因子：
--
作者：
Chen WT;Singer SJ
通讯作者：
Singer SJ