Cancer Immunobiology Laboratory, Ludwig Institute for Cancer Research, Melbourne-Austin Branch , Heidelberg, VIC , Australia ; Department of Medicine, University of Melbourne , Melbourne, VIC , Australia ; School of Cancer Medicine, La Trobe University , Melbourne, VIC , Australia.
Department of Anatomy and Neuroscience, University of Melbourne , Melbourne, VIC , Australia.
Front Oncol. 2015 Feb 16;5:36. doi: 10.3389/fonc.2015.00036. eCollection 2015.
Epithelial-to-mesenchymal transition is a hallmark event in the metastatic cascade conferring invasive ability to tumor cells. There are ongoing efforts to replicate the physiological events occurring during mobilization of tumor cells in model systems. However, few systems are able to capture these complex in vivo events. The embryonic chicken transplantation model has emerged as a useful system to assess melanoma cells including functions that are relevant to the metastatic process, namely invasion and plasticity. The chicken embryo represents an accessible and economical 3-dimensional in vivo model for investigating melanoma cell invasion as it exploits the ancestral relationship between melanoma and its precursor neural crest cells. We describe a methodology that enables the interrogation of melanoma cell motility within the developing avian embryo. This model involves the injection of melanoma cells into the neural tube of chicken embryos. Melanoma cells are labeled using fluorescent tracker dye, Vybrant DiO, then cultured as hanging drops for 24 h to aggregate the cells. Groups of approximately 700 cells are placed into the neural tube of chicken embryos prior to the onset of neural crest migration at the hindbrain level (embryonic day 1.5) or trunk level (embryonic day 2.5). Chick embryos are reincubated and analyzed after 48 h for the location of melanoma cells using fluorescent microscopy on whole mounts and cross-sections of the embryos. Using this system, we compared the in vivo invasive behavior of epithelial-like and mesenchymal-like melanoma cells. We report that the developing embryonic microenvironment confers motile abilities to both types of melanoma cells. Hence, the embryonic chicken transplantation model has the potential to become a valuable tool for in vivo melanoma invasion studies. Importantly, it may provide novel insights into and reveal previously unknown mediators of the metastatic steps of invasion and dissemination in melanoma.
上皮-间充质转化是转移级联中的一个标志性事件，赋予肿瘤细胞侵袭能力。目前正在努力在模型系统中复制肿瘤细胞动员过程中发生的生理事件。然而，很少有系统能够捕捉到这些复杂的体内事件。胚胎鸡移植模型已成为评估黑色素瘤细胞的有用系统，包括与转移过程相关的功能，即侵袭和可塑性。鸡胚作为一种可访问和经济的 3 维体内模型，可用于研究黑色素瘤细胞侵袭，因为它利用了黑色素瘤与其前体细胞神经嵴细胞之间的祖先关系。我们描述了一种能够在发育中的禽类胚胎中研究黑色素瘤细胞迁移的方法。该模型涉及将黑色素瘤细胞注射到鸡胚的神经管中。使用荧光示踪染料 Vybrant DiO 标记黑色素瘤细胞，然后将其培养在悬滴中 24 小时以聚集细胞。在神经嵴迁移开始之前（后脑水平，胚胎第 1.5 天；或躯干水平，胚胎第 2.5 天），将大约 700 个细胞组放入鸡胚的神经管中。鸡胚重新孵育，在 48 小时后使用荧光显微镜对整个胚胎和胚胎的横切片进行分析，以确定黑色素瘤细胞的位置。使用该系统，我们比较了上皮样和间充质样黑色素瘤细胞的体内侵袭行为。我们报告说，发育中的胚胎微环境赋予了这两种类型的黑色素瘤细胞迁移能力。因此，胚胎鸡移植模型有可能成为体内黑色素瘤侵袭研究的有用工具。重要的是，它可能为侵袭和传播等黑色素瘤转移步骤提供新的见解，并揭示以前未知的介质。
