Alpha-lactalbumin production in human mammary carcinoma.

Alpha-Lactalbumin was isolated from mature human milk and utilized as an immunogen in rabbits. A radioimmunoassay was developed that was capable of detecting nanogram quantities of the antigen. Alpha-Lactalbumin synthesis was detected in human breast cancer cells (MCF-7) cultivated as a continuous cell line in vitro. Other human carcinoma epithelial cell lines (throat and cervix) failed to react in this assay. The ability to synthesize alpha-lactalbumin by breast carcinoma cells appeared to be independent of the addition of prolactin to the culture medium.