RESUMO
Studying human cancer from a biomechanical perspective may contribute to pathogenesis understanding which leads to the malignancy. In this study, biomechanics of suspended and adhered breast cancer cells were investigated via the micropipette aspiration method with special emphasis on comparing the cell stiffness and viscoelastic parameters of estrogen receptor positive, ER+, MCF-7 and human epidermal growth factor receptor 2 positive, HER2 +, SKBR-3 cancer cell lines prior to and post treatment with tamoxifen and trastuzumab, respectively. Alterations of mechanical parameters included significant increase in cell stiffness, especially after treatment with trastuzumab and changes in viscoelastic parameters, in both cancer cell lines post treatment. According to immunofluorescence analysis, the raised cell stiffness was corresponded to remodeling of F-actin, which peripherally located in tamoxifen treated and perinuclear accumulated in trastuzumab treated cancer cell cytoskeleton, implying a reduced potential for cell deformation and motility. Additionally, these results were in line with the study of single and collective cell migration through Boyden chamber and wound healing assays respectively, where the potential for migration was significantly decreased after treatment. Consequently, these findings lead to an increased interest in biomechanics of cancer progression after treatment with anti-tumor agents, importantly in understanding the effect of the alterations of mechanical properties upon the possibility for change in metastatic potential.