Immunofluorescent characterization of fibronectin, laminin, and keratin in normal and neoplastic human mammary epithelial cells in culture and in breast tissue sections.
Employing indirect immunofluorescent staining, primary and secondary serum-free cultures and frozen sections of human mammary tissue, normal and neoplastic, were examined for the presence and distribution of fibronectin (FN) and keratin, and frozen sections also for laminin (LM). The epithelial cell purity of the cultures was confirmed by the observation that all cells stained with anti-keratin antibody. In confluent cultures, FN was absent at the apical cell surface, and was seen as a fibrillar matrix exclusively beneath the epithelial monolayer, at the cell-substratum interface. No differences were noted between normal and neoplastic cells in vitro. In sections of normal breast tissue, FN was localized in the basement membrane zone (BMZ) and in the connective tissue stroma. A distinguishing feature of the neoplastic tissue was the considerably more intensive anti-FN immunofluorescence of the stroma. In normal tissue sections, LM was present exclusively in the BMZ, where it formed a continuous, well-delineated, smooth line; this line was found to be distorted, interrupted, and sometimes entirely absent in the neoplastic tissue. The cytoplasm of all cultured cells, neoplastic as well as normal, exhibited a dense network of keratin filaments that was especially prominent around the nucleus. In the sections, keratin was ubiquitously present in the epithelial cells, predominantly along the interior border of the surface membrane; in the neoplastic tissue, this pattern was markedly disorganized, and some of the cells failed to express the substance.
D001940:Breast / Q000166:cytology* / Q000473:pathology; D001943:Breast Neoplasms / Q000473:pathology*; D002478:Cells, Cultured; D005260:Female; D005353:Fibronectins / Q000032:analysis*; D005455:Fluorescent Antibody Technique; D006801:Humans; D007633:Keratins / Q000032:analysis*; D007797:Laminin / Q000032:analysis*
D005353:Fibronectins; D007797:Laminin; D007633:Keratins