1. Introduction

The cytoskeleton of eukaryotes is a dynamic complex three-dimensional network of filamentous proteins present within the cytoplasm. It consists of microfilaments mainly composed of G actin, intermediate filaments made up of keratins and vimentins and microtubules composed of α and β-tubulin^[1] (Figure 1a and b). Cytoskeleton plays an essential role in controlling the cell shape by providing mechanical support, enabling cell motility and facilitating intra cellular transport. It also serves as a scaffold for signaling cascades by providing sites for localization and anchoring of signaling molecules. Dysregulation of cytoskeleton leads to numerous diseases including cancer^[2].

Figure 1. (a) Immunofluorescent image of HeLa cells showing actin (green) tubulin (red tubulin antibody labelled with Cy3 secondary) and nucleus (blue). PFA fixed HeLa cells were stained for actin (Phalloidin 488) and alpha tubulin (Alexa 647) and image was taken using airy scan mode in Zeiss 800 confocal microscope using 63× objective. Scale bar = 5 µm. (b) Graphical representation of the cytoskeletal components of a cell like actin, tubulin, and intermediate filaments.

2. Metastasis

Successful metastasis depends on cell invasion, migration, host immune escape, extravasation, and angiogenesis. The process of cell invasion and migration relies on the dynamic changes taking place in the cytoskeletal components; actin, tubulin and intermediate filaments. This is possible due to the plasticity of the cytoskeleton and coordinated action of all the three, is crucial for the process of metastasis from the primary site. Changes in cellular architecture by internal clues will affect the cell functions leading to the formation of different protrusions like lamellipodia, filopodia, and invadopodia that help in cell migration eventually leading to metastasis, which is life threatening than the formation of neoplasms.

3. Cytoskeletal Components

Actin, microtubules and Intermediate Filaments form the components of the cytoskelton. Actin networks are necessary for wide range of cellular processes which depend on actin’s ability to switch between monomeric G and polymeric F actin Polymerization and depolymerization of actin are spatially and temporally regulated by family of actin binding proteins (ABPs) that are involved in capping, crosslinking, severing, and bundling of actin filaments. Microtubules are formed by the association of alpha  and  beta tubulin heterodimers, which assemble in a head-to-tail fashion as linear protofilaments that give rise to hollow cylinder with inner and outer diameter of 12 nm and 25 nm. Intermediate filaments  are highly dynamic, apolar fibrous structures, that are present in the peinuclear region and extend through the cytoplasm. Co-ordination of all the three components are necessary for the correct functioning of the cell and any dysregulation leads to cancer.