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Cancer-associated fibroblasts (CAFs) play an active role in remodeling the local tumor stroma to support tumor initiation, growth, invasion, metastasis, and therapeutic resistance. The CAF-secreted chemokine, CXCL12, has been directly implicated in the tumorigenic progression of carcinomas, including breast cancer. Using a 3-D in vitro microfluidic-based microtissue model, we demonstrate that stromal CXCL12 secreted by CAFs has a potent effect on increasing the vascular permeability of local blood microvessel analogues through paracrine signaling. Moreover, genetic deletion of fibroblast-specific CXCL12 significantly reduced vessel permeability compared to CXCL12 secreting CAFs within the recapitulated tumor microenvironment (TME). We suspected that fibroblast-mediated extracellular matrix (ECM) remodeling and contraction indirectly accounted for this change in vessel permeability. To this end, we investigated the autocrine effects of CXCL12 on fibroblast contractility and determined that antagonistic blocking of CXCL12 did not have a substantial effect on ECM contraction. Our findings indicate that fibroblast-secreted CXCL12 has a significant role in promoting a leakier endothelium hospitable to angiogenesis and tumor cell intravasation; however, autocrine CXCL12 is not the primary upstream trigger of CAF contractility.
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Fibroblasts Promote Proliferation and Matrix Invasion of Breast Cancer Cells in Co‐Culture Models
Abstract Fibroblasts are an abundant cell type in tumor microenvironments. Activated fibroblasts, known as carcinoma‐associated fibroblasts (CAFs), interact with cancer cells through biochemical signaling and render cancer cells proliferative, invasive, and resistant to therapeutics. Targeting CAFs–cancer cells interactions offers a strategy to block cancer progression. 2D and 3D co‐cultures of human mammary fibroblasts and triple negative breast cancer (TNBC) cells are used to investigate the impact of heterotypic cellular interactions on the proliferation of matrix invasion of TNBC cells. The results show that fibroblasts secreting a chemokine, CXCL12, significantly enhance proliferation of TNBC cells expressing the chemokine receptor, CXCR4. Disrupting this interaction with a receptor antagonist normalizes cancer cell proliferation to that of a co‐culture model lacking this signaling. When co‐culture spheroids are embedded in collagen, fibroblasts producing CXCL12 promote collagen invasion of TNBC cells. Although co‐cultures containing normal fibroblasts also lead to TNBC cell spreading into the matrix, a morphological analysis of cells and inhibition of chemokine‐receptor signaling shows that this spreading is due to the incompatibility of fibroblasts and cancer cells leading to the segregation of the two cell types from the spheroid.
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- Award ID(s):
- 1801591
- PAR ID:
- 10459736
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Therapeutics
- Volume:
- 2
- Issue:
- 11
- ISSN:
- 2366-3987
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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