A PROTEIN REACTED WITH ANTI-VITRONECTIN ANTIBODY ACCUMULATES IN TUMORS DERIVED FROM B16F10 MELANOMA-CELLS

Vitronectin is a cell-adhesive glycoprotein in blood plasma and extrac ellular matrix. We have examined the participation of vitronectin in e xperimental metastasis of B16F10 mouse melanoma cells which metastasiz ed to lung. By Western blotting, a protein reacted with anti-rat vitro nectin antibody was found to be enriched more in the melanoma parenchy ma in the lung than the sum of cultured melanoma cells and normal lung tissue. The protein was similarly abundant in tumors of B16F10 cells grown subcutaneously in mice. By immunofluorescence of the tissues, th e signal detected with anti-rat vitronectin was found to be localized at nuclei in melanoma cells metastasized in the lung as web as in tumo rs just grown subcutaneously. These results indicate that the protein reacted with anti-vitronectin antibody is expressed much more in the g rowing mass of B16F10 melanoma cells in vivo than in vitro.