Correlation between the lung distribution patterns of Lu‐Ecam‐1 and melanoma experimental metastases

Lu-ECAM-1 is a 90-kDa lectin-like, melanoma-cell-binding endothelial-cell adhesion molecule that mediates colonization of the lungs by B16-F10 melanoma cells. The well-known formation of pleural and sub-pleural B16-F10 melanoma colonies is correlated quantitatively with prominent histochemical staining of endothelia of pleural capillaries and sub-pleural venules with anti-Lu-ECAM-1 MAb 6D3. The less frequent endothelial staining of perivenous and peribronchial venules is associated with fewer B16-F10 colonies in these locations, and the occasional segmental staining of pulmonary veins coincides with rare tumor nodules which usually expand in an asymmetric fashion around these veins. Lu-ECAM-1 is also expressed on endothelia of some tumor vessels, indicating that these vessels are recruited from the same host blood vessels that originally caused the arrest of blood-borne B16-F10 melanoma cells. The close association between the lung distribution patterns of Lu-ECAM-1-positive blood vessels and experimental melanoma metastases is further evidence of the importance of endothelial-cell adhesion molecules in the formation of metastases.