Characterisation of Tunnelling Nanotubes in Oral Carcinoma Cell Lines

Abstract In our study, we discovered the presence of tunnelling nanotubes (TNTs) in three oral carcinoma cell lines, suggesting an alternative form of cellular communication. These TNTs act as channels for the movement of membrane-bound vesicles and microRNAs (miRNAs), indicating their potential influence on cancer progression and intercellular interactions. Our findings demonstrate that TNTs can form spontaneously under normal growth conditions, not just as a stress response. Through time-lapse microscopy, we captured the rapid and dynamic process of TNT formation, typically occurring within 20-40 minutes, via two primary methods: actin-driven cellular extensions and sustained connectivity during cell division. We also successfully visualised the active transfer of miRNA mimics through these TNTs. Notably, we detected the presence of AGO2 protein within the TNTs, implying its involvement in the delivery of miRNAs to recipient cells. Our study adds to the overall understanding of TNTs in the context of oral cancer biology and suggests a broader role for these structures in molecular transport.