Lectin-binding patterns in transplantable mouse mammary tumors and their metastases

Lectin binding was assessed in a transplantable pregnancy-dependent mouse mammary tumor line (TPDMT-4), its autonomous sublines (T4-0196 and T4-01165) and their artificial metastases (lung colonies), using the avidin-biotin-peroxidase technique. Soybean agglutinin (SBA) and peanut agglitinin (PNA) bound to the luminal surfaces of TPDMT-4 tumor cells, while dolicos biflorus agglutinin (DBA) showed no binding. In T4-0196 and T4-01165 tumors as well as their lung metastases, SBA and PNA binding was mixed and both positive and negative cells were detected, indicating that these lectins were not associated with the metastatic phenotype. Although the T4-0196 and T4-01165 sublines had a mixture of DBA-positive and DBA-negative cells, all the metastatic T4-0196 subclones contained only DBA-positive cells and all the metastatic T4-01165 subclones had DBA-negative cells. Thus DBA-positive, and DBA-negative subclones had respectively metastasized to the lungs from these autonomous sublines, implying that the carbohydrate moieties detected by DBA were not associated with metastatic potential but that the lung metastases were clonal in origin.