Wu Z Z, Zhang G, Long M, Wang H B, Song G B, Cai S X
College of Bioengineering, Key Laboratory for Biomechanics and Tissue Engineering, State Ministry of Education, Chongqing University, Chongqing 400044, P.R. China.
Biorheology. 2000;37(4):279-90.
The viscoelastic properties of both hepatocytes and hepatocellular carcinoma (HCC) cells were measured by means of a micropipette aspiration technique. Experimental results were analyzed with a three-element standard linear solid model, in which an elastic element, K1, is in parallel with a Maxwell element composed of another elastic element, K2, in series with a viscous element, mu. Further, we investigated the relevance of viscoelastic properties of these two types of cells to the cytoskeleton structures by treating cells with three cytoskeletal perturbing agents, namely cytochalasin D (CD), colchicine (Col) and vinblastine (VBL). The results showed that the elastic coefficients, but not viscous coefficient of HCC cells (K1 = 103.6 +/- 12.6 N m-2, K2 = 42.5 +/- 10.4 N m-2, mu = 4.5 +/- 1.9 Pa s, n = 30), were significantly higher than the corresponding values for hepatocytes (K1 = 87.5 +/- 12.1 N m-2, K2 = 33.3 +/- 10.3 N m-2, mu = 5.9 +/- 3.0 Pa s, n = 24). Upon treatment with CD, the viscoelastic coefficients of both hepatocytes and HCC cells decreased uniformly, with magnitudes for the decrease in elastic coefficients of HCC cells (K1: 68.7 to 81.7 N m-2, 66.3 to 78.9%; K2: 34.5 to 37.1 N m-2, 81.2 to 87.3%) larger than those for normal hepatocytes (K1: 42.6 to 49.8 N m-2, 48.7 to 56.9%; K2: 17.2 to 20.4 N m-2, 51.7 to 61.3%). There was a smaller decrease in the viscous coefficient of HCC cells (2.0 to 3.4 Pa s, 44.4 to 75.6%) than that for hepatocytes (3.0 to 3.9 Pa s, 50.8 to 66.1%). Upon treatment with Col and VBL, the elastic coefficients of hepatocytes generally increased or tended to increase while those of HCC cells decreased. The differences in either the pattern or the magnitude of the effect of cytoskeletal perturbing agent on the viscoelastic properties between HCC cells and hepatocytes might possibly reflect differences in the state of the cytoskeleton structure and function, or in the cells' sensitivity to perturbing agent treatment between these two types of cells. Changes in the viscoelastic properties of cancer cells might well affect tumor cell invasion and metastasis as well as interactions between tumor cells and their micro-mechanical environments.
采用微量吸管吸取技术测量了肝细胞和肝癌（HCC）细胞的粘弹性特性。实验结果用三元标准线性固体模型进行分析，其中弹性元件K1与由另一个弹性元件K2和粘性元件μ串联组成的麦克斯韦元件并联。此外，我们用三种细胞骨架干扰剂，即细胞松弛素D（CD）、秋水仙碱（Col）和长春碱（VBL）处理细胞，研究了这两种细胞的粘弹性特性与细胞骨架结构的相关性。结果显示，HCC细胞的弹性系数（K1 = 103.6 +/- 12.6 N m-2，K2 = 42.5 +/- 10.4 N m-2，μ = 4.5 +/- 1.9 Pa s，n = 30）显著高于肝细胞的相应值（K1 = 87.5 +/- 12.1 N m-2，K2 = 33.3 +/- 10.3 N m-2，μ = 5.9 +/- 3.0 Pa s，n = 24），而粘性系数无显著差异。用CD处理后，肝细胞和HCC细胞的粘弹性系数均均匀下降，HCC细胞弹性系数的下降幅度（K1：从68.7至81.7 N m-2，下降66.3至78.9%；K2：从34.5至37.1 N m-2，下降81.2至87.3%）大于正常肝细胞（K1：从42.6至49.8 N m-2，下降48.7至56.9%；K2：从17.2至20.4 N m-2，下降51.7至61.3%）。HCC细胞粘性系数的下降幅度（从2.0至3.4 Pa s，下降44.4至75.6%）小于肝细胞（从3.0至3.9 Pa s，下降50.8至66.1%）。用Col和VBL处理后，肝细胞的弹性系数通常增加或趋于增加，而HCC细胞的弹性系数则下降。细胞骨架干扰剂对HCC细胞和肝细胞粘弹性特性影响的模式或幅度差异可能反映了这两种细胞在细胞骨架结构和功能状态上的差异，或对干扰剂处理的敏感性差异。癌细胞粘弹性特性的变化很可能会影响肿瘤细胞的侵袭和转移以及肿瘤细胞与其微机械环境之间的相互作用。
