Abstract：
To overcome the limitations of in vitro two-dimensional (2D) cancer models in mimicking the complexities of the native tumor milieu, three-dimensional (3D) engineered cancer models using biomimetic materials have been introduced to more closely recapitulate the key attributes of the tumor microenvironment. Specifically, for colorectal cancer (CRC), a few studies have developed 3D engineered tumor models to investigate cell-cell interactions or efficacy of anti-cancer drugs. However, recapitulation of CRC cell line phenotypic differences within a 3D engineered matrix has not been systematically investigated. Here, we developed an in vitro 3D engineered CRC (3D-eCRC) tissue model using the natural-synthetic hybrid biomaterial PEG-fibrinogen and three CRC cell lines, HCT 116, HT-29, and SW480. To better recapitulate native tumor conditions, our 3D-eCRC model supported higher cell density encapsulation (20 × 106 cells/mL) and enabled longer term maintenance (29 days) as compared to previously reported in vitro CRC models. The 3D-eCRCs formed using each cell line demonstrated line-dependent differences in cellular and tissue properties, including cellular growth and morphology, cell subpopulations, cell size, cell granularity, migration patterns, tissue growth, gene expression, and tissue stiffness. Importantly, these differences were found to be most prominent from Day 22 to Day 29, thereby indicating the importance of long-term culture of engineered CRC tissues for recapitulation and investigation of mechanistic differences and drug response. Our 3D-eCRC tissue model showed high potential for supporting future in vitro comparative studies of disease progression, metastatic mechanisms, and anti-cancer drug candidate response in a CRC cell line-dependent manner.
摘要：
为了克服体外二维（2D）癌症模型在模仿天然肿瘤环境的复杂性方面的局限性，已经引入了使用仿生材料的三维（3D）工程癌症模型，以更紧密地概括肿瘤微环境的关键属性。具体来说,对于结直肠癌（CRC），一些研究已经开发了3D工程肿瘤模型来研究细胞-细胞相互作用或抗癌药物的疗效.然而,尚未系统地研究3D工程基质中CRC细胞系表型差异的概述。这里,我们使用天然合成的混合生物材料PEG-纤维蛋白原和三种CRC细胞系开发了体外3D工程CRC（3D-eCRC）组织模型，HCT116、HT-29和SW480。为了更好地概括天然肿瘤状况，与先前报道的体外CRC模型相比,我们的3D-eCRC模型支持更高的细胞包封密度(20×106个细胞/mL),并且能够实现更长期的维持(29天).使用每种细胞系形成的3D-eCRC在细胞和组织特性方面表现出依赖于线的差异。包括细胞生长和形态，细胞亚群，细胞大小,单元格粒度,迁移模式，组织生长,基因表达，和组织硬度。重要的是,发现这些差异在第22天至第29天最为突出,这表明长期培养工程化CRC组织对于重述和研究机制差异和药物反应的重要性.我们的3D-eCRC组织模型显示出支持未来疾病进展的体外比较研究的高潜力，转移机制，和以CRC细胞系依赖性方式的抗癌药物候选反应。
