Comparative analysis of secretion of S100A4 metastatic marker by immune and tumor cells

S100A4 protein is present in low concentrations (2.1–15.7 ng/10 6 cells) in lymphocyte and neutrophil culture medium. Addition of stimulants to the cells did not lead to an appreciable increase in the content of this protein. The initial content of S100A4 is significantly higher (92–447 ng/10 6 cells) in culture media of highly metastatic KSML-100 adenocarcinoma and M3 and B16 melanoma cells. The release of S100A4 by these cells significantly increased after addition of lymphocytes and Tag7/Hsp70 cytotoxic complex. Repeated injection of antibodies to S100A4 to mice with transplanted M3 melanoma inhibited tumor growth.