Ajeti Visar, Lara-Santiago Jorge, Alkmin Samuel, Campagnola Paul J
Department of Biomedical Engineering, University of Wisconsin-Madison, 1550 Engineering Drive, Madison, WI 53706.
Cell Mol Bioeng. 2017 Aug;10(4):295-311. doi: 10.1007/s12195-017-0492-9. Epub 2017 Jul 10.
Migration mis-regulation is a hallmark of cancer, and remains an important problem in cancer biology. We postulate the needs for better in vitro models to understand the details of cell-matrix interactions. Here, we utilized multiphoton excited (MPE) photochemistry to fabricate models to systematically study migration dynamics operative in breast and ovarian cancer. Gradients are a convenient means to modulate concentration and also have been implicated in metastases.
We specifically pattern sub-micron structured gradients from laminin and fibronectin whose up-regulation is associated with increased metastasis and poor prognosis. We developed a new continuous linear bi-directional gradient design, permitting exploration of the underlying cell-matrix interactions of migration, including speed, directness, and f-actin cytoskeleton alignment as a function of concentration. These new models provide both contact guidance and ECM binding cues, and provide a more relevant environment than possible with existing technologies such as flow chambers or 2D printed surfaces.
We found an overall increase in these processes with increasing concentration on both laminin and fibronectin gradients for a series of ovarian and breast cancer lines. Moreover, directness was higher for more metastatic cells, indicating that epithelial or mesenchymal state of the cell type governs the dynamics. However, the specifics of the speed and directedness depend on both the cell type and protein, thus we found that we must consider these processes collectively to obtain a self-consistent picture of the migration. For this purpose, we performed a linear discriminate analysis (LDA) and successfully classified the different cell types on the two protein gradients without molecular biology analysis.
The bi-gradient structures are versatile tools to performing detailed studies of cell migration, specifically haptotxis. We further suggest the can be used in assessing efficacy of drug treatments targeted at specific matrix components.
迁移调控异常是癌症的一个标志，并且仍然是癌症生物学中的一个重要问题。我们推测需要更好的体外模型来了解细胞与基质相互作用的细节。在此，我们利用多光子激发（MPE）光化学来构建模型，以系统地研究在乳腺癌和卵巢癌中起作用的迁移动力学。梯度是调节浓度的便捷手段，并且也与转移有关。
我们从层粘连蛋白和纤连蛋白特异性地构建亚微米结构梯度，它们的上调与转移增加和预后不良相关。我们开发了一种新的连续线性双向梯度设计，允许探索迁移过程中潜在的细胞与基质相互作用，包括速度、方向性以及作为浓度函数的丝状肌动蛋白细胞骨架排列。这些新模型既提供接触导向又提供细胞外基质结合线索，并且提供了比现有技术（如流动腔室或二维打印表面）更相关的环境。
对于一系列卵巢癌和乳腺癌细胞系，我们发现随着层粘连蛋白和纤连蛋白梯度浓度的增加，这些过程总体上有所增加。此外，转移性更强的细胞方向性更高，表明细胞类型的上皮或间充质状态决定了动力学。然而，速度和方向性的具体情况取决于细胞类型和蛋白质，因此我们发现必须综合考虑这些过程才能获得迁移的自洽图景。为此，我们进行了线性判别分析（LDA），并在无需分子生物学分析的情况下成功地在两种蛋白质梯度上对不同细胞类型进行了分类。
双梯度结构是进行细胞迁移详细研究（特别是趋触性研究）的通用工具。我们进一步建议它们可用于评估针对特定基质成分的药物治疗效果。
