Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland; Maryland Biophysics Program, IPST, University of Maryland, College Park, Maryland.
Maryland Biophysics Program, IPST, University of Maryland, College Park, Maryland; Fischell Department of Bioengineering, University of Maryland, College Park, Maryland.
Biophys J. 2022 Oct 4;121(19):3586-3599. doi: 10.1016/j.bpj.2022.09.002. Epub 2022 Sep 5.
The mechanical phenotype of the cell is critical for survival following deformations due to confinement and fluid flow. One idea is that cancer cells are plastic and adopt different mechanical phenotypes under different geometries that aid in their survival. Thus, an attractive goal is to disrupt cancer cells' ability to adopt multiple mechanical states. To begin to address this question, we aimed to quantify the diversity of these mechanical states using in vitro biomimetics to mimic in vivo two-dimensional (2D) and 3D extracellular matrix environments. Here, we used two modalities Brillouin microscopy (∼GHz) and broadband frequency (7-15 kHz) optical tweezer microrheology to measure microscale cell mechanics. We measured the response of intracellular mechanics of cancer cells cultured in 2D and 3D environments where we modified substrate stiffness, dimensionality (2D versus 3D), and presence of fibrillar topography. We determined that there was good agreement between two modalities despite the difference in timescale of the two measurements. These findings on cell mechanical phenotype in different environments confirm a correlation between modalities that employ different mechanisms at different temporal scales (Hz-kHz versus GHz). We also determined that observed heterogeneity in cell shape is more closely linked to the cells' mechanical state. Moreover, individual cells in multicellular spheroids exhibit a lower degree of mechanical heterogeneity when compared with single cells cultured in monodisperse 3D cultures. The observed decreased heterogeneity among cells in spheroids suggested that there is mechanical cooperativity between cells that make up a single spheroid.
细胞的力学表型对于其在受到限制和流体流动而变形后的存活至关重要。有一种观点认为，癌细胞具有可塑性，并且在不同的几何形状下会采用不同的力学表型，以帮助它们存活。因此，一个有吸引力的目标是破坏癌细胞采用多种力学状态的能力。为了开始解决这个问题，我们旨在使用体外仿生学来量化这些力学状态的多样性，以模拟体内二维（2D）和三维（3D）细胞外基质环境。在这里，我们使用两种模式布里渊显微镜（约 1GHz）和宽带频率（7-15kHz）光镊微流变学来测量微尺度细胞力学。我们测量了在改变基底刚度、维度（2D 与 3D）和纤维状形貌存在的情况下，在 2D 和 3D 环境中培养的癌细胞的细胞内力学响应。我们发现，尽管两种测量的时间尺度不同，但两种模式之间存在很好的一致性。这些关于不同环境中细胞力学表型的发现证实了采用不同机制在不同时间尺度（Hz-kHz 与 GHz）的模式之间存在相关性。我们还确定，细胞形状的观察到的异质性与细胞的机械状态更密切相关。此外，与在单分散 3D 培养物中培养的单细胞相比，多细胞球体中的单个细胞表现出较低程度的机械异质性。在球体中观察到的细胞间异质性降低表明，构成单个球体的细胞之间存在机械协同作用。
