Cancer metastasis remains a critical area of study within the field of cancer research. The tumor microenvironment (TME), comprising various cell types and the extracellular matrix (ECM), plays a...Show moreCancer metastasis remains a critical area of study within the field of cancer research. The tumor microenvironment (TME), comprising various cell types and the extracellular matrix (ECM), plays a pivotal role in controlling tumor initiation and progression. Here we show an investigation into the mechanical phenotype of Hs 578T breast cancer cells within the TME, focusing particularly on the role of cell-ECM interactions in modulating cellular traction forces. Hs 578T cells with an integrin- α2 (ITGA2) stable knockout were utilized, and the resulting pressures were compared between the control and knockout at different collagen concentrations. Attention is hence given to the ITGA2 and its role in mediating cell-ECM interactions. Through the utilization of elastic hydrogel microparticles as localized stress sensors and advanced microscopy techniques, we show that increasing the collagen concentration results in increased traction forces exerted by control breast cancer cells. Conversely, the traction forces by ITGA2 Hs 578T knockout cells remain unaffected by changes in collagen concentration. Also, a linear relationship between the traction and its standard deviation, regardless of the Hs 578T cell type and collagen concentration, is observed. The findings contribute to a deeper understanding of cancer biomechanics, offering insights into potential therapeutic targets for inhibiting metastatic spread in breast cancer.Show less
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
Mechanical forces regulate many cell functions such as differentiation and proliferation. Existing traction force methodology is often limited to measurements in the two-dimensional plane. Recent...Show moreMechanical forces regulate many cell functions such as differentiation and proliferation. Existing traction force methodology is often limited to measurements in the two-dimensional plane. Recent studies have used hydrogel micro-particles to measure cell forces in a complex 3D environment such as a spheroid. However, these micro-particles have not been fully characterised. We show here the synthesis of hydrogel micro particles with size and stiffness similar to cells. We also show that the measured effective Young’s modulus is dependent on the size of the particle measured. The softest beads with a Young’s modulus of 175 Pa can measure normal stresses down to ~ 7.3 Pa. The synthesised beads can be used to determine cell forces in tissues such a tumour spheroids or can be used to mimic cells in tissue layers.Show less
