Haage Amanda, Schneider Ian C
Department of Genetics, Development, and Cell Biology, Molecular, Cellular and Developmental Biology Interdepartmental Graduate Program, and.
Department of Genetics, Development, and Cell Biology, Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa, USA
FASEB J. 2014 Aug;28(8):3589-99. doi: 10.1096/fj.13-245613. Epub 2014 May 1.
The pathogenesis of cancer is often driven by local invasion and metastasis. Recently, mechanical properties of the tumor microenvironment have been identified as potent regulators of invasion and metastasis, while matrix metalloproteinases (MMPs) are classically known as significant enhancers of cancer cell migration and invasion. Here we have been able to sensitively measure MMP activity changes in response to specific extracellular matrix (ECM) environments and cell contractility states. Cells of a pancreatic cancer cell line, Panc-1, up-regulate MMP activities between 3- and 10-fold with increased cell contractility. Conversely, they down-regulate MMP activities when contractility is blocked to levels seen with pan-MMP activity inhibitors. Similar, albeit attenuated, responses are seen in other pancreatic cancer cell lines, BxPC-3 and AsPC-1. In addition, MMP activity was modulated by substrate stiffness, collagen gel concentration, and the degree of collagen cross-linking, when cells were plated on collagen gels ranging from 0.5 to 5 mg/ml that span the physiological range of substrate stiffness (50-2000 Pa). Panc-1 cells showed enhanced MMP activity on stiffer substrates, whereas BxPC-3 and AsPC-1 cells showed diminished MMP activity. In addition, eliminating heparan sulfate proteoglycans using heparinase completely abrogated the mechanical induction of MMP activity. These results demonstrate the first functional link between MMP activity, contractility, and ECM stiffness and provide an explanation as to why stiffer environments result in enhanced cell migration and invasion.
癌症的发病机制通常由局部侵袭和转移驱动。最近，肿瘤微环境的力学特性已被确定为侵袭和转移的有效调节因子，而基质金属蛋白酶（MMPs）传统上被认为是癌细胞迁移和侵袭的重要增强因子。在这里，我们能够灵敏地测量MMP活性响应特定细胞外基质（ECM）环境和细胞收缩状态的变化。胰腺癌细胞系Panc-1的细胞随着细胞收缩性增加，MMP活性上调3至10倍。相反，当收缩性被阻断至泛MMP活性抑制剂所观察到的水平时，它们下调MMP活性。在其他胰腺癌细胞系BxPC-3和AsPC-1中也观察到类似但减弱的反应。此外，当细胞接种在浓度范围为0.5至5 mg/ml、涵盖生理范围底物硬度（50 - 2000 Pa）的胶原凝胶上时，MMP活性受底物硬度、胶原凝胶浓度和胶原交联程度的调节。Panc-1细胞在更硬的底物上显示出增强的MMP活性，而BxPC-3和AsPC-1细胞显示出减弱的MMP活性。此外，使用肝素酶消除硫酸乙酰肝素蛋白聚糖完全消除了MMP活性的机械诱导。这些结果证明了MMP活性、收缩性和ECM硬度之间的首个功能联系，并解释了为什么更硬的环境会导致细胞迁移和侵袭增强。
