Isolation of breast cancer tumour antigen from serum and urine.

Abstract

AbstractA blocking tube leukocyte adherence inhibition assay (tube LAI) was used to detect and monitor the isolation of blocking factor from the serum and urine of advanced breast cancer patients. The results of the present study indicate that the blocking factor in serum and urine was soluble breast cancer TSA. In the serum, TSA chromatographed in the region of about 80,000 to >150,000 mol. wt and was shown not to be IgG. By the technique of polyanion precipitation, the TSA was shown to be lipoprotein in nature and co‐isolated with high‐density lipoproteins. In the urine, the TSA chromatographed in the region of about 48,000 mol. wt and this suggested that the serum TSA had undergone enzymatic cleavage prior to filtration. By immuno‐adsorbent affinity chromatography with xeno‐antisera directed to the xenoantigenic determinant of HLA, blocking factor (TSA) was isolated from sera from patients with metastatic breast cancer. The specificity of binding of TSA to the immuno‐adsorbent columns and the immunologically specific abrogation of LAI reactivity were clearly shown. Breast cancer TSA was also isolated from serum by immunoadsorbent affinity columns with human cytophilic IgG anti‐tumour antibody to breast cancer. The tumour‐specific antigenic determinant of human breast cancer appeared either to be associated with the major histocompatibility complex or to be a modified HLA antigen. The present study has defined the features of breast TSA present in serum and urine and it is possible that, from these sources and with these methods, sufficient quantities of pure TSA can be isolated.