A dynamic in vivo model of epithelial-to-mesenchymal transitions in circulating tumor cells and metastases of breast cancer
A dynamic in vivo model of epithelial-to-mesenchymal transitions in circulating tumor cells and metastases of breast cancer
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DOI：
10.1038/onc.2011.540
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发表时间：
2012-08-01
期刊：
影响因子：
8
通讯作者：
Gilles, C.
中科院分区：
文献类型：
--
作者：
Bonnomet, A.;Syne, L.;Gilles, C.
上皮-间充质转化（EMT）过程赋予上皮细胞增强的迁移/侵袭特性，因此可能有助于肿瘤的侵袭和转移扩散。由于在人类肿瘤中跟踪EMT过程的困难，我们开发了一种具有可移植人类乳腺肿瘤细胞（MDA-MB-468）的动物模型，并对其进行了表征，该模型独特地显示了自发EMT事件的发生。将波形蛋白作为EMT的标记物，在原发MDA-MB-468异种移植物中发现了波形蛋白阴性和波形蛋白阳性区域的异质性，在临床人类浸润性乳腺肿瘤标本中也观察到这种异质性。对这些异种移植物群体进行显微解剖后的逆转录酶pcr显示，EMT在vimentin阳性区表现为“间充质基因”表达增强（蜗牛、Slug和成纤维细胞特异性蛋白-1）和上皮分子表达减少（E-cadherin、ZO-3和JAM-A）。注射sc后8天，血液中就检测到循环肿瘤细胞（ctc），通过体内成像分析和组织学检查，所有注射的动物都发生了肺转移。通过逆转录定量PCR在ctc中检测到高水平的波形蛋白RNA，在较小程度上也检测到蜗牛和蛞蝓RNA。血管性血友病因子/波形蛋白双免疫染色进一步显示血管肿瘤栓塞的肿瘤细胞均表达波形蛋白。肺内的肿瘤栓塞也表达波形蛋白，而大转移灶显示异质波形蛋白表达，如原发性异种移植物所见。总之，我们的数据在体内环境中独特地证明了EMT发生在原发肿瘤中，并与增强的内渗和生成ctc的能力相关。他们进一步表明，间质-上皮现象发生在次要器官，促进转移生长。中华肿瘤杂志，2012,31 (3):341 - 353；doi: 10.1038 / onc.2011.540;2011年11月28日在线发布
Epithelial-to-mesenchymal transition (EMT) processes endow epithelial cells with enhanced migratory/invasive properties and are therefore likely to contribute to tumor invasion and metastatic spread. Because of the difficulty in following EMT processes in human tumors, we have developed and characterized an animal model with transplantable human breast tumor cells (MDA-MB-468) uniquely showing spontaneous EMT events to occur. Using vimentin as a marker of EMT, heterogeneity was revealed in the primary MDA-MB-468 xenografts with vimentin-negative and vimentin-positive areas, as also observed on clinical human invasive breast tumor specimens. Reverse transcriptase-PCR after microdissection of these populations from the xenografts revealed EMT traits in the vimentin-positive zones characterized by enhanced 'mesenchymal gene' expression (Snail, Slug and fibroblast-specific protein-1) and diminished expression of epithelial molecules (E-cadherin, ZO-3 and JAM-A). Circulating tumor cells (CTCs) were detected in the blood as soon as 8 days after s.c. injection, and lung metastases developed in all animals injected as examined by in vivo imaging analyses and histology. High levels of vimentin RNA were detected in CTCs by reverse transcriptase-quantitative PCR as well as, to a lesser extent, Snail and Slug RNA. Von Willebrand Factor/vimentin double immunostainings further showed that tumor cells in vascular tumoral emboli all expressed vimentin. Tumoral emboli in the lungs also expressed vimentin whereas macrometastases displayed heterogenous vimentin expression, as seen in the primary xenografts. In conclusion, our data uniquely demonstrate in an in vivo context that EMT occurs in the primary tumors, and associates with an enhanced ability to intravasate and generate CTCs. They further suggest that mesenchymal-to-epithelial phenomena occur in secondary organs, facilitating the metastatic growth. Oncogene (2012) 31, 3741-3753; doi:10.1038/onc.2011.540; published online 28 November 2011