Tunneling nanotubes between two mesothelioma cells.

Intercellular communication is critical to cancer cell proliferation, coordination, and tumor invasion. Tunneling nanotubes (TnTs) are fine, long, non-adherent, actin-based cytoplasmic extensions with which cells can connect to other cells and transmit cytoplasmic contents.  TnTs have previously been demonstrated in cell cultures and have been shown to transfer viruses and signals between cells.

In this paper, the authors demonstrated that TnTs form between mesothelioma cells lying close or far from each other, and found evidence for TnTs in actual tumors, both mesothelioma and lung adenocarcinoma.  Confocal microscopy was used to capture images of TnTs connecting fixed cells and live cells and time-lapse imaging was used to investigate transfer of proteins, mitochondria, and Golgi vesicles.  (see Supplemental material for movies)

This is the first documented evidence that TnTs form between mesothelioma cells in culture, as well as in actual tumors resected from patients.   The authors propose that TnTs are critical to providing a direct cytoplasmic connection between invasive malignant mesothelioma cells and play an important role in cancer cell pathogenesis and invasion. This work further supports the idea that cancer cells may also be capable of acquiring genes which induce resistance to chemotherapy in this fashion as well.  Inhibition of nanotube formation might possible represent a therapeutic option in the future.

Read the article here.