Perspectives of cellular communication through tunneling nanotubes in cancer cells and the connection to radiation effects

Table 1 Overview and comparison between intercellular connections and membrane protrusions similar to TNTs

Name	Diameter	Length	Cell-to-cell contact	Cytosceletal content	Positioning in-vitro	References
TNT	50–1500 nm	Few to over 100 μm	Yes	F-actin, some microtubules, some cytokeratin filaments	Usually above substrate	[8, 24]
Cytoneme	< 200 nm	Up to 70 μm	No	F-actin, no microtubules	N/A, tissue only	[44, 45]
Filopodia	100–300 nm	Several μm	No	F-actin, no microtubules	Contact to substrate	[46]
Gap junctions	< 10 nm	~ 10 nm	Yes	N/A	Above substrate	[47]
Epithilial bridges	1–20 μm	25–100 μm	Yes	F-actin, microtubules	Above stubstrate	[48]

ISSN: 1748-717X