Monoclonal antibodies inhibit the adhesion of mouse B 16 melanoma cells in vitro and block lung metastasis in vivo.

Seven monoclonal antibodies against mouse B 16 melanoma cells (produced in syngeneic C57BL/6 mice) were selected that blocked the adhesion of melanoma cells to tissue culture dishes. These antibodies were found to be directed against antigens on the surface of mouse B 16 melanoma cells but not on normal mouse cells such as 3T3 fibroblasts. Similarly, the antigens could not be detected in normal mouse tissues (e.g., lung, kidney, liver) but were found in lungs colonized by B 16 melanoma cells. Significantly, three of these antibodies virtually abolished lung colonization of highly invasive B 16 sublines injected into the animals' bloodstream. They exerted their effect both when preabsorbed by the melanoma cell in vitro and when delivered to the animals prior to the tumor cells. It is suggested that monoclonal antibodies might be a promising tool for preventing metastasis.