Antigenic Heterogeneity of Human Mammary Carcinoma Cells Defined by Monoclonal Antibodies

Abstract Murine monoclonal antibodies, reactive with human mammary tumor associated antigens, have been generated using membrane-enriched fractions of human metastatic mammary carcinomas as immunogens. Antigenic variation was observed in the expression of specific tumor-associated antigens among and within individual mammary tumor masses using these monoclonal antibodies. This diversity was also observed in human mammary tumor cell lines and clones of the MCF-7 mammary tumor cell line grown in-vitro . Antigenic drift was observed with continued passage of mammary tumor cell lines.