High levels of Met-72 antigen expression: correlation with metastatic activity of B16 melanoma tumor cell variants.

In the present study, both poorly and highly metastatic clones derived from the C57BL/6 mouse B16 melanoma were used with cyclophosphamide in an attempt to elicit host antibody responses against cell surface markers expressed on highly metastatic tumor variants. The immunizations, performed in both syngeneic and xenogeneic combinations in Lewis rats, resulted in the production of 3 mouse and 2 rat monoclonal antibodies (MoAb) that preferentially react with highly metastatic clones derived from the B16 melanoma. These MoAb all immunoprecipitated a 72,000-dalton, cell surface-expressed glycoprotein, referred to as Met-72. In this study, 2 of the mouse anti-Met-72 MoAb were examined in detail for a) tumor specificity, b) reactivity against normal mouse tissue by in vivo absorption, and c) their ability to discriminate highly metastatic clones derived from the B16 melanoma.