Tumor metastasis is a multi-step process driven by different types of cells, such as cancer cells, fibroblasts, endothelial and immune cells. The interaction among these cells and tumor microenvironment plays a key role in cancer progression . Mesenchymal stem cells (MSCs) gained attention since they are reported to contribute to the tumor progression by modulating the immune surveillance and promoting angiogenesis [2-3]. However, MSCs also inhibit the tumor progression and for this reason, they are considered potential target of anti-tumoral agents . 3D in vitro tumor models are a useful tool to limit the use of animal models in cancer research, to carry out precise and efficient drug testing as well as to understand the tumor progression mechanism . To better study the mechanisms underpinning the cross talk between breast cancer microenvironment and MSCs, we developed a dynamic cell culture system, based on a modified in-series connected LIVEBOX 1 bioreactors (IVTech, Italy). The experimental set up was based on the co-culture of 3D-bmMSCs and 3D-HMF/MDA-MB-231 seeded onto silk fibroin scaffolds, grown in two serially connected LIVEBOX 1 bioreactors. The separated cultures (3D-bmMSCs and 3D-HMF/MDA-MB-231) were used as control and static/dynamic conditions were analyzed. The cell viabilities in static - and dynamic conditions were monitored by mean of LIVE/DEAD assay. The morphologies of the cells were assessed by means of DAPI/Phalloidin staining. The gene expressions of ECM-related markers were investigated. The dynamic in vitro models developed in this work aims to investigate in depth the controversial role of MSCs in the tumor progression and invasion.
This work is supported by EU-Horizon 2020 grant FoReCaST (agreement nr.668983) and by BREAST-IT FCT project (PTDC/BTM-ORG/28168/2017).
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