Modeling and quantification of cancer cell invasion through collagen type I matrices.

Tumor invasion is the outcome of a complex interplay between cancer cells and the stromal environment. Considering the contribution of the stromal environment, we developed a membrane-free single-cell and spheroid based complementary model to study cancer invasion through native collagen type-I matrices. Cell morphology is preserved during the assays allowing real time monitoring of invasion-induced changes in cell structure and F-actin organization. Combining these models with computerized quantification permits the calculation of highly reproducible and operator-independent data. These assays are versatile in the use of fluorescent probes and have a flexible kinetic endpoint. Once the optimal experimental conditions are empirically determined, the collagen type-I invasion assays can be used for preclinical validation of small-molecule inhibitors targeting invasion. Initiation and monitoring of the single-cell and spheroid invasion model can be achieved in 8 h (over 3 days) and in 14 h (over 8 days) respectively.