Exosomes from oral squamous carcinoma cell lines, SQUU-A and SQUU-B, define the tropism of lymphatic dissemination

Oral squamous cell carcinoma (OSCC) is often associated with lymphatic rather than hematogenous metastasis; however, a determinant factor for this process has not been elucidated. This study examined the effect of OSCC-derived exosomes on angiogenesis and lymphangiogenesis, closely related with hematogenous and lymphatic metastasis, respectively. Our data demonstrated that OSCC-derived exosomes stimulated the expression of VEGFs and their receptors, essential regulators of angiogenesis and lymphangiogenesis, in human lymphatic endothelial cells but not in human vein endothelial cells. These results suggest that specific exosomes have differential tropism toward a certain cell type, defining the modality of metastasis.