muramidase and Carcinoma--Intraductal--Noninfiltrating

Elastosis associated with invasive ductal and lobular carcinomas of the breast was examined by tinctorial and immunohistochemical staining methods, enzyme digestion, and electron microscopy. The elastotic material exhibited the tinctorial staining properties of elastic fibres, and the ultrastructural appearances were those of elastic fibres although there was a higher proportion of microfibrils than in normal mature elastic fibres. The elastosis was immunostained by antisera to human fetal elastin, lysozyme and amyloid P component, as in other sites where elastic fibres are found. These findings indicate that immunohistochemically intact elastic fibres are present in the elastosis of breast cancer. They also demonstrate that lysozyme and amyloid P component are co-distributed with elastic fibres in elastosis of breast carcinoma, as distinct components with different susceptibilities to enzyme digestion. The cellular origin of elastosis in breast carcinoma remains uncertain.

Topics: Actin Cytoskeleton; Adult; Aged; Breast Neoplasms; Carcinoma, Intraductal, Noninfiltrating; Elastic Tissue; Elastin; Female; Humans; Microscopy, Electron; Middle Aged; Muramidase; Serum Amyloid P-Component

Antibodies to alpha-elastin peptides, amyloid P component, lysozyme and plasma protease inhibitors have been used in an immunoperoxidase method to stain elastic fibres in frozen sections of human breast tissues. A loss of immunoreactivity seen in formalin-fixed, paraffin-embedded sections was reversed by a preliminary proteolysis. Differences in the tinctorial dye and immunohistochemical staining patterns following proteolysis by a variety of enzymes suggests a selective unmasking or removal of elastic fibre components and thus the presence of separate binding sites for individual antibodies and tinctorial dyes. Antibody blocking experiments and double immunoenzymatic labelling support the existence of several different epitopes within elastic fibres.

Topics: Amyloid; Breast Neoplasms; Carcinoma, Intraductal, Noninfiltrating; Coloring Agents; Elastic Tissue; Elastin; Female; Humans; Immunoenzyme Techniques; Muramidase; Peptide Hydrolases; Protease Inhibitors; Serum Amyloid P-Component; Staining and Labeling