Quantitative Analysis of the Effect of Cancer Invasiveness and Collagen Concentration on 3D Matrix Remodeling

Abstract

Extracellular matrix (ECM) remodeling is a key component of cell migration and tumor metastasis, and has been associated with cancer progression. Despite the importance of matrix remodeling, systematic and quantitative studies on the process have largely been lacking. Furthermore, it remains unclear if the disrupted tensional homeostasis characteristic of malignancy is due to initially altered ECM and tissue properties, or to the alteration of the tissue by tumor cells. To explore these questions, we studied matrix remodeling by two different prostate cancer cell lines in a three-dimensional collagen system. Over one week, we monitored structural changes in gels of varying collagen content using confocal reflection microscopy and quantitative image analysis, tracking metrics of fibril fraction, pore size, and fiber length and diameter. Gels that were seeded with no cells (control), LNCaP cells, and DU-145 cells were quantitatively compared. Gels with higher collagen content initially had smaller pore sizes and higher fibril fractions, as expected. However, over time, LNCaP- and DU-145-populated matrices showed different structural properties compared both to each other and to the control gels, with LNCaP cells appearing to favor microenvironments with lower collagen fiber fractions and larger pores than DU-145 cells. We posit that the DU-145 cells' preference for denser matrices is due to their higher invasiveness and proteolytic capabilities. Inhibition of matrix proteases resulted in reduced fibril fractions for high concentration gels seeded with either cell type, supporting our hypothesis. Our novel quantitative results probe the dynamics of gel remodeling in three dimensions and suggest that prostate cancer cells remodel their ECM in a synergistic manner that is dependent on both initial matrix properties as well as their invasiveness.

Combinative in vitro studies and computational model to predict 3D cell migration response to drug insult

“…Samples were concentrated via ultracentrifugation using a 10 kDa cutoff filter and subsequently mixed with 4× zymography loading buffer before being analyzed via zymographic technique described previously (38). …”

Human cardiac fibroblast extracellular matrix remodeling: dual effects of tissue inhibitor of metalloproteinase-2

“…CRM collects autofluorescent signals reflected by the matrix fibers and allows for 3D structural reconstruction of the matrix [13]. Constructs were excited with a low-density 405 nm laser and the emitted light between 420 and 480 nm was collected.…”

Computational Modeling of Stem Cell Migration: A Mini Review

“…Cells will display different behavior when on a one, two or three dimensional space 14 ; for example, while most cells have lower speeds in a 3D environment than on a 2D culture surface, neutrophils display almost no migration in 2D substrates and do migrate when embedded in 3D collagen gels. 23,24 Observations such as this have led to both the development and engineering of in vitro platforms to study migration as well as consideration of this phenomenon in CM. 24,49,55 The internal differences in gene and protein expression of different cell types are now considered in CM.…”