| Abstract: | Monoclonal antibodies which are considered to be able to differentiate epithelial and myoepithelial cells in the breast have been developed. Human mammary carcinoma cell line (HBC-4W) was used for immunization. Monoclonal antibodies-B4B2F10 (epi-1), E9E8B7 (myo-1)-with IgM was examined using tissues from diseased breast by avidin-biotin-peroxidase assay. Epi-1 antibody reacted with epithelial cells while myo-1 antibody reacted with myoepithelial cells in the mammary glands, respectively. The reaction was markedly visible, in particular, in fibroadenoma, mastopathy, and papilloma, which showed clear two-cell-type structures. In the infiltrating ductal carcinoma, epi-1 antibody reacted with carcinoma cells, while myo-1 antibody reacted with stromal cells rather than carcinoma cells suggesting that infiltrating ductal carcinoma was mainly of epithelial origin. In the infiltrating lobular carcinoma, however, myo-1 as well as epi-1 antibodies reacted with carcinoma cells. It is suggested that infiltrating lobular carcinoma was of a mixture of epithelial and myoepithelial cell origin. |
