Migration of tumor cells in 3D matrices is governed by matrix stiffness along with cell-matrix adhesion and proteolysis

Abstract

Cell migration on 2D surfaces is governed by a balance between counteracting tractile and adhesion forces. Although biochemical factors such as adhesion receptor and ligand concentration and binding, signaling through cell adhesion complexes, and cytoskeletal structure assembly/disassembly have been studied in detail in a 2D context, the critical biochemical and biophysical parameters that affect cell migration in 3D matrices have not been quantitatively investigated. We demonstrate that, in addition to adhesion and tractile forces, matrix stiffness is a key factor that influences cell movement in 3D. Cell migration assays in which Matrigel density, fibronectin concentration, and β1 integrin binding are systematically varied show that at a specific Matrigel density the migration speed of DU-145 human prostate carcinoma cells is a balance between tractile and adhesion forces. However, when biochemical parameters such as matrix ligand and cell integrin receptor levels are held constant, maximal cell movement shifts to matrices exhibiting lesser stiffness. This behavior contradicts current 2D models but is predicted by a recent force-based computational model of cell movement in a 3D matrix. As expected, this 3D motility through an extracellular environment of pore size much smaller than cellular dimensions does depend on proteolytic activity as broad-spectrum matrix metalloproteinase (MMP) inhibitors limit the migration of DU-145 cells and also HT-1080 fibrosarcoma cells. Our experimental findings here represent, to our knowledge, discovery of a previously undescribed set of balances of cell and matrix properties that govern the ability of tumor cells to migration in 3D environments.

Effects of extracellular matrix analogues on primary human fibroblast behavior

“…Cellular growth and morphology is heavily influenced by mechanical stimulation and cues coming from the ECM, as well as soluble autocrine and paracrine regulatory signals [7,41]. Matrix composition, stiffness and topography play crucial roles in cellular morphology, behavior and tissue development [42,43].…”

An agarose-based microfluidic platform with a gradient buffer for 3D chemotaxis studies

“…To date, most cell migration experiments in 3D with live cell imaging are performed in open multiwell systems, chamber slides (Zaman et al 2006), or custom-made sealed chambers Gunzer et al 1997;Wolf et al 2007) which do not readily permit the application of welldefined external chemical gradients. Modified Boyden chambers for 3D cell invasion (Semino et al 2006;Shields et al 2007) are not conducive to live cell imaging and therefore key parameters like migration speed, persistence ratio, and percentage of migratory cells remain largely unexplored.…”

Contribution of Bone Tissue Modulus to Breast Cancer Metastasis to Bone

“…Many studies investigating the effects of the rigidity of the matrix on cell migration, differentiation, and invasion have used 2D cell culture on hydrogel substrates, including Matrigel™ [77], crosslinked gelatin [78], and synthetic hydrogels [79]. Similarly, the invasiveness of cancer cells has been reported to increase with matrix rigidity when cultured on hydrogels [51,52,78,80].…”