Figure 2.

Indirect interactions between MSC and cancer cells are performed by a mutual exchange of a plethora of soluble factors, including microvesicles and exosomes, which may also provide therapeutic vehicles [75,76]. Moreover, direct cell–cell interactions include gap junctional intercellular communication (GIJC), signaling via notch receptor and ligand, and exchange of cytoplasmatic compounds and small organelles (e.g., mitochondria) via nanotubes or trogocytosis. Tight assembly of the two plasma membranes from MSC and cancer cells provide a fusion permissive prerequisite for subsequent hybrid cell formation. Further mechanisms add to the generation of hybrid cells, which undergo a post-hybrid selection process (PHSP) to cope with aneuploidy and chromosomal instabilities. (adapted from [77]).