Fig. 3

Integrins responsible for the liver metastasis of melanoma and the inhibitors. Integrin α2 and α5 may be involved in mediating liver metastasis in melanoma. Integrin α2 exerts this function mainly via binding to collagen type IV, which is highly present in the liver sinusoids and important for the collagen type IV-dependent activation of FAK. One of the α2 isoforms, α2β1, which is activated by VE-cadherin, was also found to promote liver metastasis of melanoma in a preclinical model. β1 integrins, including α2β1 and α5β1, and the downstream c-Met, Src and FAK pathway may also contribute to liver metastasis by promoting tumor cell invasion and transendothelial migration. Volociximab (M200) and ATN-161 are supposed to inhibit liver metastasis by binding to the α5 subunit of integrin α5β1