A Biomimetic High Throughput Model of Cancer Cell Spheroid Dissemination onto Aligned Fibrillar Collagen

Cell dissemination during tumor development is a characteristic of cancer metastasis. Dissemination from three-dimensional spheroid models on extracellular matrices designed to mimic tissue-specific physiological microenvironments may allow us to better elucidate the mechanism behind cancer metastasis and the response to therapeutic agents. The orientation of fibrillar collagen plays a key role in cellular processes and mediates metastasis through contact-guidance. Understanding how cells migrate on aligned collagen fibrils requires in vitro assays with reproducible and standardized orientation of collagen fibrils on the macro-to-nanoscale. Herein, we implement a spheroid-based migration assay, integrated with a fibrillar type I collagen matrix, in a manner compatible with high throughput image acquisition and quantitative analysis. The migration of highly proliferating U2OS osteosarcoma cell spheroids onto an aligned fibrillar type I collagen matrix was quantified. Cell dissemination from the spheroid was polarized with increased invasion in the direction of fibril alignment. The resulting area of cell dissemination had an aspect ratio of 1.2 +/- 0.1 and an angle of maximum invasion distance of 5 degrees +/- 44 degrees relative to the direction of collagen fibril alignment. The assay described here can be applied to a fully automated imaging and analysis pipeline for the assessment of tumor cell migration with high throughput screening.

Automated summary

Cell dissemination is a key characteristic of cancer metastasis, and studying this process in vitro can provide insights into the mechanisms and therapeutic responses. The orientation of fibrillar collagen plays a crucial role in cell migration, and reproducible assays are needed to understand how cells migrate on aligned collagen fibrils. In this study, a spheroid-based migration assay integrated with a fibrillar type I collagen matrix was used to quantify the migration of osteosarcoma cells. The results showed polarized cell dissemination with increased invasion in the direction of fibril alignment.