Antisera against a novel 60-kD antigen (P60) were developed using immunomasking strategy which shows malignant growth-related expression in human breast cancer tissue. Cell adhesion assay in the presence of P60 antibody clearly indicates a role for P60 directly or indirectly in adhesion of tumor cells to extracellular matrix protein vitronectin. These results indicate that P60 could be a potential marker to distinguish benign from malignant growth of human breast tissue, and that P60 could be an integrin or a non-integrin receptor, or a receptor-related protein to vitronectin.
