Collagen Fiber Array of Peritumoral Stroma Influences Epithelial-to-Mesenchymal Transition and Invasive Potential of Mammary Cancer Cells

Abstract

: Interactions of cancer cells with matrix macromolecules of the surrounding tumor stroma are critical to mediate invasion and metastasis. In this study, we reproduced the collagen mechanical barriers in vitro (i.e., basement membrane, lamina propria under basement membrane, and deeper bundled collagen fibers with different array). These were used in 3D cell cultures to define their effects on morphology and behavior of breast cancer cells with different metastatic potential (MCF-7 and MDA-MB-231) using scanning electron microscope (SEM). We demonstrated that breast cancer cells cultured in 2D and 3D cultures on different collagen substrates show different morphologies: i) a globular/spherical shape, ii) a flattened polygonal shape, and iii) elongated/fusiform and spindle-like shapes. The distribution of different cell shapes changed with the distinct collagen fiber/fibril physical array and size. Dense collagen fibers, parallel to the culture plane, do not allow the invasion of MCF-7 and MDA-MB-231 cells, which, however, show increases of microvilli and microvesicles, respectively. These novel data highlight the regulatory role of different fibrillar collagen arrays in modifying breast cancer cell shape, inducing epithelial-to-mesenchymal transition, changing matrix composition and modulating the production of extracellular vesicles. Further investigation utilizing this in vitro model will help to demonstrate the biological roles of matrix macromolecules in cancer cell invasion in vivo.

Tendon Biomimetic Electrospun PLGA Fleeces Induce an Early Epithelial-Mesenchymal Transition and Tenogenic Differentiation on Amniotic Epithelial Stem Cells

“…This interesting result demonstrates that an aligned topography exercises an instructive function on cells by strongly influencing their biology. The obtained results are in line with the observation on the epithelial MCF-7 cells that were grown on a collagen fibrillar network underwent the EMT by strongly increasing their mesenchymal markers (vimentin, fibronectin), whereas their epithelial marker (E-cadherin) was decreased and also their cell morphology was modified [77]. Even if a direct relation between EMT and tenogenic lineage differentiation has not been reported yet, it has been demonstrated using a tendon injury model that shows genes that play a role in EMT processes such as Snail1, Slug, Goosecoid, and Twist1 are coordinately regulated during the tendon regeneration [78,79].…”

Morphological State Transition Dynamics in EGF-Induced Epithelial to Mesenchymal Transition

“…Franchi et al [46] have earlier shown that membrane filters used as inserts in cell culture experiments affects the morphology of MCF-7 cells. However, we did not observe such an effect of membrane insert on the morphology of the cells in our Boyden chamber assay.…”

Extracellular Matrix-Mediated Breast Cancer Cells Morphological Alterations, Invasiveness, and Microvesicles/Exosomes Release

“…In conclusion, cross talk between breast cancer cells observed in 3D Millipore cultures as compared to 2D flask cultures, is enhanced by fibronectin substrate which ensures an increased cell adhesion to the ground culture and promotes increasing vesicles production [ 49 ]. When cells encounter a thick layer of Matrigel they are stimulated to develop also invadopodia while attempting to cross the basement membrane [ 74 ]. Collagen, always favoring morphological changes, seems to interact with breast cancer of the various phenotypes in relation to the different concentrations which define different collagen fibrils arrays and porosity [ 70 , 75 ].…”