Epithelial-mesenchymal crosstalk influences cellular behavior in a 3D alveolus-fibroblast model system

Abstract

Interactions between lung epithelium and interstitial fibroblasts are increasingly recognized as playing a major role in the progression of several lung pathologies, including cancer. Three-dimensional in vitro co-culture systems offer tissue-relevant platforms to study the signaling interplay between diseased and healthy cell types. Such systems provide a controlled environment in which to probe the mechanisms involved in epithelial-mesenchymal crosstalk. To recapitulate the native alveolar tissue architecture, we employed a cyst templating technique to culture alveolar epithelial cells on photodegradable microspheres and subsequently encapsulated the cell-laden spheres within poly (ethylene glycol) (PEG) hydrogels containing dispersed pulmonary fibroblasts. A fibroblast cell line (CCL-210) was co-cultured with either healthy mouse alveolar epithelial primary cells or a cancerous alveolar epithelial cell line (A549) to probe the influence of tumor-stromal interactions on proliferation, migration, and matrix remodeling. In 3D co-culture, cancerous epithelial cells and fibroblasts had higher proliferation rates. When examining fibroblast motility, the fibroblasts migrated faster when co-cultured with cancerous A549 cells. Finally, a fluorescent peptide reporter for matrix metalloproteinase (MMP) activity revealed increased MMP activity when A549s and fibroblasts were co-cultured. When MMP activity was inhibited or when cells were cultured in gels with a non-degradable crosslinker, fibroblast migration was dramatically suppressed, and the increase in cancer cell proliferation in co-culture was abrogated. Together, this evidence supports the idea that there is an exchange between the alveolar epithelium and surrounding fibroblasts during cancer progression that depends on MMP activity and points to potential signaling routes that merit further investigation to determine targets for cancer treatment.

Probing coordinated co-culture cancer related motility through differential micro-compartmentalized elastic substrates

“…These results indicate the difference in motility due to cell types and cell substrates, but also partially due to the different distributions of the two cell types between substrates of various stiffness. Crosstalk between fibroblast and epithelial cells has been recognized as a common response in tumor progression 41 , 42 . Many studies have discovered cancer-associated fibroblasts enhance the motility of cancer cells through multiple regulatory signals including α-smooth muscle actin, SMAD family number-3 (SMAD3), cyclin-dependent kinase inhibitor-1, miR-29b, etc.…”

How to build a lung: latest advances and emerging themes in lung bioengineering

“…trauma, local bronchiectasis, tracheal collapse and nonsmall cell lung cancer) could benefit from these approaches. Techniques to manufacture alveolar-like structures [82,85,86,127], tracheal supports [99,100] and replacements [146] have all been developed recently. Furthermore, there has been work on the development of biomaterials that can serve as artificial pleuras for diseases and acute conditions that affect the visceral pleura (e.g.…”

“…Due to the difficulty associated with manufacturing a scaffold with geometrical parameters suitable for parenchymal lung tissue, there have been limited reports. To date, potential scaffolds for parenchymal tissue engineering have been fabricated via foaming [82,83], porogen-solvent techniques, cryogelation [84], photodegradation [85,86] and self-assembly of microspheres [87]. Although these techniques are able to recapitulate alveolar-like structures, they lack the vasculature and airways required for integration into recipients, and ultimately for gas exchange.…”

Microfluidic and Paper-Based Devices for Disease Detection and Diagnostic Research

“…Lewis et al studied how the co-culture of pulmonary fibroblasts with mouse alveolar epithelial cells, a cancerous alveolar epithelial cell line, influenced tumor–stromal interactions during proliferation, migration, and matrix remodeling. The 3D co-culture system found increased proliferation rates, a greater degree of fibroblast motility, and increased MMP activity [ 107 ]. Interestingly, they observed a decrease in MMP activity and migration in the human adenocarcinoma A549 cell line when they were co-cultured with a non-degradable gel.…”