J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA.
Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida, USA.
Tissue Eng Part A. 2021 Apr;27(7-8):438-453. doi: 10.1089/ten.TEA.2020.0190. Epub 2020 Nov 18.
A challenge in cancer research is the lack of physiologically responsive models that enable tracking of cancer cells in tissue-like environments. A model that enables real-time investigation of cancer cell migration, fate, and function during angiogenesis does not exist. Current models, such as 2D or 3D culturing, can contain multiple cell types, but they do not incorporate the complexity of intact microvascular networks. The objective of this study was to establish a tumor microvasculature model by demonstrating the feasibility of bioprinting cancer cells onto excised mouse tissue. Inkjet-printed DiI breast cancer cells on mesometrium tissues from C57Bl/6 mice demonstrated cancer cells' motility and proliferation through time-lapse imaging. Colocalization of DAPI nuclei confirmed that DiI cancer cells remained intact postprinting. Printed DiI 4T1 cells also remained viable after printing on Day 0 and after culture on Day 5. Time-lapse imaging over 5 days enabled tracking of cell migration and proliferation. The number of cells and cell area were significantly increased over time. After culture, cancer cell clusters were colocalized with angiogenic microvessels. The number of vascular islands, defined as disconnected endothelial cell segments, was increased for tissues with bioprinted cancer cells, which suggests that the early stages of angiogenesis were influenced by the presence of cancer cells. Bioprinting cathepsin L knockdown 4T1 cancer cells on wild-type tissues or nontarget 4T1 cells on NG2 knockout tissues served to validate the use of the model for probing tumor cell versus microenvironment changes. These results establish the potential for bioprinting cancer cells onto live mouse tissues to investigate cancer microvascular dynamics within a physiologically relevant microenvironment. Impact statement To keep advancing the cancer biology field, tissue engineering has been focusing on developing tumor biomimetic models that more closely resemble the native microenvironment. We introduce a novel methodology of bioprinting exogenous cancer cells onto mouse tissue that contains multiple cells and systems within native physiology to investigate cancer cell migration and interactions with nearby microvascular networks. This study corroborates the manipulation of different exogenous cells and host microenvironments that impact cancer cell dynamics in a physiologically relevant tissue. Overall, it is a new approach for delineating the effects of the microenvironment on cancer cells and vice versa.
癌症研究的一个挑战是缺乏能够在类似组织的环境中跟踪癌细胞的生理反应模型。目前还没有能够实时研究血管生成过程中癌细胞迁移、命运和功能的模型。目前的模型，如 2D 或 3D 培养，可以包含多种细胞类型，但它们没有纳入完整微血管网络的复杂性。本研究的目的是通过证明将癌细胞生物打印到切除的小鼠组织上的可行性来建立肿瘤微血管模型。喷墨打印的 DiI 乳腺癌细胞在 C57Bl/6 小鼠的 mesometrium 组织上进行了时间 lapse 成像，显示了癌细胞的运动和增殖。DAPI 核的共定位证实了打印后 DiI 癌细胞的完整性。在第 0 天打印后和第 5 天培养后，打印的 DiI 4T1 细胞仍然存活。在 5 天的时间 lapse 成像中，可以跟踪细胞的迁移和增殖。随着时间的推移，细胞数量和细胞面积显著增加。培养后，癌细胞簇与血管生成微血管共定位。与生物打印癌细胞的组织相比，具有血管岛的数量（定义为不连续的内皮细胞段）增加，这表明血管生成的早期阶段受到癌细胞的影响。将 cathepsin L 敲低的 4T1 癌细胞生物打印到野生型组织上或非靶向的 4T1 细胞生物打印到 NG2 敲除组织上，验证了该模型用于探测肿瘤细胞与微环境变化的用途。这些结果确立了将癌细胞生物打印到活小鼠组织上以在生理相关的微环境中研究癌症微血管动力学的潜力。
影响说明为了不断推进癌症生物学领域的发展，组织工程一直专注于开发更能模拟天然微环境的肿瘤仿生模型。我们介绍了一种将外源性癌细胞生物打印到含有多种细胞和系统的天然生理小鼠组织上的新方法，以研究癌细胞的迁移和与附近微血管网络的相互作用。这项研究证实了对不同外源性细胞和宿主微环境的操纵会影响癌症细胞在生理相关组织中的动力学。总的来说，这是一种新的方法，可以描述微环境对癌细胞的影响，反之亦然。
