Abstract
Amoeboid movement is characteristic for rounded cells, which do not form strong adhesion contacts with the ECM and use blebs as migratory protrusions. It is well known that actin is the main component of mature forms of these structures, but the exact role fulfilled by non-muscle actin isoforms β- and γ- in bleb formation and migration of these cells is still not fully understood. The aim of this study was to establish the role of β- and γ-actin in migration of bleb-forming cancer cells using isoform-specific antibodies and expression of fluorescently tagged actin isoforms. We observed, after staining with monoclonal antibodies, that both actins are present in these cells in the form of a cortical ring as well as in the area of blebs. Additionally, using simultaneous expression of differentially tagged β- and γ-actin in cells, we observed that the actin isoforms are present together in a single bleb. They were involved during bleb expansion as well as retraction. Also present in the area of these protrusions formed by both isoforms were the bleb markers–ezrin and myosin II. The overexpression of β- or γ-actin led to actin cytoskeletal rearrangement followed by the growth of migration and invasion abilities of examined human colon cancer cells, LS174T line. In summary these data prove that both actin isoforms have an impact on motility of bleb-forming cancer cells. Moreover, we conclude that monoclonal antibodies directed against actin isoforms in combination with the tagged actins are good tools to study their role in important biological processes.
Highlights
Actin is an abundant protein which is essential for proper cell functioning
We have previously shown that both actin isoforms, β and γ, are present within multiple Factin-rich membrane protrusions formed by mesenchymally migrating cells [29,30]
The actin cytoskeleton of these cells is visible as a cortical ring under the cellular membrane with bleb-like protrusions containing filamentous actin as well as ezrin (Fig 1), which links the actin cytoskeleton to the cell membrane and is essential for bleb formation and can be treated as a migratory bleb marker [40,58,59]
Summary
Actin is an abundant protein which is essential for proper cell functioning. It takes part in many physiological processes including cell motility, signal transduction, maintenance of cell shape, ring formation during cytokinesis, cell adhesion, transcription and muscle contraction [1]. Among them are β- and γ-non-muscle, αskeletal, α-cardiac, and α-and γ-smooth muscle isoactins [2]. The α-actins as well as γ-smooth muscle actin are present typically within muscle tissue, whereas non-muscle β- and γ-actin isoforms, essential for cell survival, are present in almost all cell types [3].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
