To better understand tumor progression and metastasis, it is important to investigate the mechanical properties of its cellular components. Tumors generally consist of cancer cells and healthy...Show moreTo better understand tumor progression and metastasis, it is important to investigate the mechanical properties of its cellular components. Tumors generally consist of cancer cells and healthy cells, whose interactions are fundamental for their structure and functionality. It has been shown that in co-cultured spheroids, cells rearrange themselves and completely separate. To closely mimic the tumor micro-environment in-vitro, hetero-spheroids containing both cancer cells and fibroblasts were used. The forces generated during cell-cell interaction and their cell sorting were studied. The interaction between the two cell types was probed with cell-sized (15-30 μm) microparticles. Different seeding-times and number ratios were investigated. No significant difference in the stress fields applied by the two different cell types during their interaction was found. However, it was observed that there is a critical number ratio between 1:3 and 1:6, above which the two cell types tend to completely separate. Below the critical ratio, there were intermixed areas of both cell lines. These cell clusters tend to merge over time, however no complete phase separation of the two cell types was observed for a period of one week. These results show that there is a favourable rearrangement of the cells consisting tumor-like structures. This cell type separation could indicate the next steps towards understanding the clustering and detachment of the cancer cells from the primary tumor, during metastasis.Show less
