Department of Biomedical Engineering, The Catholic University of America, Washington, District of Columbia.
Research Service, Veterans Affairs Medical Center, Washington, District of Columbia.
Biotechnol Bioeng. 2020 Jun;117(6):1826-1838. doi: 10.1002/bit.27308. Epub 2020 Feb 28.
Extracellular matrix microstructure and mechanics are crucial to breast cancer progression and invasion into surrounding tissues. The peritumor collagen network is often dense and aligned, features which in vitro models lack. Aspiration of collagen hydrogels led to densification and alignment of microstructure surrounding embedded cancer cells. Two metastasis-derived breast cancer cell lines, MDA-MB-231 and MCF-7, were cultured in initially 4 mg/ml collagen gels for 3 days after aspiration, as well as in unaspirated control hydrogels. Videomicroscopy during aspiration, and at 0, 1, and 3 days after aspiration, epifluorescence microscopy of phalloidin-stained F-actin cytoskeleton, histological sections, and soluble metabolic byproducts from constructs were collected to characterize effects on the embedded cell morphology, the collagen network microstructure, and proliferation. Breast cancer cells remained viable after aspiration-ejection, proliferating slightly less than in unaspirated gels. Furthermore, MDA-MB-231 cells appear to partially relax the collagen network and lose alignment 3 days after aspiration. Aspiration-ejection generated aligned, compact collagen network microstructure with immediate cell co-orientation and higher cell number density apparently through purely physical means, though cell-collagen contact guidance and network remodeling influence cell organization and collagen network microstructure during subsequent culture. This study establishes a platform to determine the effects of collagen density and alignment on cancer cell behavior, with translational potential for anticancer drug screening in a biomimetic three-dimensional matrix microenvironment, or implantation in preclinical models.
细胞外基质的微观结构和力学特性对乳腺癌的进展和浸润周围组织至关重要。肿瘤周围的胶原网络通常致密且排列整齐，而体外模型则缺乏这些特征。胶原水凝胶的抽吸导致了嵌入癌细胞周围微观结构的致密化和排列。两种转移性乳腺癌细胞系 MDA-MB-231 和 MCF-7 在抽吸后最初 4mg/ml 的胶原凝胶中培养 3 天，以及在未抽吸的对照水凝胶中培养。在抽吸过程中和抽吸后 0、1 和 3 天时进行视频显微镜检查，对鬼笔环肽染色的 F-肌动蛋白细胞骨架的相差显微镜检查、组织学切片和构建物的可溶性代谢副产物进行收集，以表征对嵌入细胞形态、胶原网络微观结构和增殖的影响。抽吸-喷射后乳腺癌细胞仍然存活，增殖略低于未抽吸的凝胶。此外，MDA-MB-231 细胞似乎在抽吸后 3 天部分松弛了胶原网络并失去了排列。抽吸-喷射产生了排列整齐、致密的胶原网络微观结构，伴随着细胞的共同取向和更高的细胞密度，显然是通过纯粹的物理手段，尽管细胞-胶原接触引导和网络重塑在随后的培养过程中影响细胞组织和胶原网络微观结构。这项研究建立了一个平台，用于确定胶原密度和排列对癌细胞行为的影响，具有在仿生三维基质微环境中进行抗癌药物筛选或在临床前模型中植入的转化潜力。
