Tumor production in the nude mouse, fibrinolytic activity and cross-reactivity with antimelanoma sera of various human tumor cell lines.

It has been reported previously that antisera produced in non human primates against many cultured human melanoma lines recognize tumor-associated antigens on the melanoma cells. The reactivity correlated with other parameters of malignancy, such as rapidity of tumor growth in nude mice and release of plasminogen activator. In this study we have investigated whether these antisera also react with non melanoma cancer lines and searched for a correlation between this reaction and the other parameters of malignancy. There was cross-reactivity of the ten sera with 4-43% of the 46 non melanoma lines compared to 62-100% of the 16 melanoma lines, indicating a preferential reactivity with melanoma lines. For the non-melanoma lines no correlation was found between the release of plasminogen activator, the degree of tumorigenicity in the nude mouse or the reactivity of surface antigens as detected with antimelanoma sera.