The formation of membrane protrusions during migration is reliant upon the cells’ cytoskeletal structure and stiffness. It has been reported that actin disruption blocks protrusion and decreases cell stiffness whereas microtubule disruption blocks protrusion but increases stiffness in several cell types. In melanoma, cell migration is of concern as this cancer spreads unusually rapidly during early tumour development. The aim of this study was to characterise motility, structural properties and stiffness of human melanoma cells at radial growth phase (RGP), vertical growth phase (VGP), and metastatic stage (MET) in two-dimensional in vitro environments. Wound assays, western blotting and mitochondrial particle tracking were used to assess cell migration, cytoskeletal content and intracellular fluidity. Our results indicate that cell motility increase with increasing disease stage. Despite their different motility, RGP and VGP cells exhibit similar fluidity, actin and tubulin levels. MET cells, however, display increased fluidity which was associated with increased actin and tubulin content. Our findings demonstrate an interplay between actin and microtubule activity and their role in increasing motility of cells while minimizing cell stiffness at advanced disease stage. In earlier disease stages, cell stiffness may however not serve as an indicator of migratory capabilities.

迁移过程中膜突起的形成依赖于细胞的细胞骨架结构和硬度。据报道肌动蛋白破坏阻止突起并降低细胞刚度，而微管破坏阻止突起但增加几种细胞类型的刚度。在黑色素瘤中，细胞迁移受到关注，因为这种癌症在早期肿瘤发展过程中异常迅速地扩散。这项研究的目的是在二维体外表征人黑素瘤细胞在放射状生长阶段（RGP），垂直生长阶段（VGP）和转移阶段（MET）的运动性，结构特性和刚度环境。伤口测定，蛋白质印迹和线粒体颗粒追踪用于评估细胞迁移，细胞骨架含量和细胞内流动性。我们的结果表明，细胞运动性随着疾病阶段的增加而增加。尽管它们的运动性不同，RGP和VGP细胞仍具有相似的流动性，肌动蛋白和微管蛋白水平。然而，MET细胞显示出增加的流动性，这与肌动蛋白和微管蛋白含量增加有关。我们的发现表明肌动蛋白和微管活性之间的相互作用，以及它们在增加细胞运动性的同时最小化疾病晚期的细胞僵硬性的作用。然而，在疾病的早期阶段，细胞刚度可能不能用作迁移能力的指标。