elastin and Carcinoma--Intraductal--Noninfiltrating

The tumor microenvironment regulates tissue development and homeostasis, and its dysregulation contributes to neoplastic progression. Increased expression of type X collagen α-1 (ColXα1) in tumor-associated stroma correlates with poor pathologic response to neoadjuvant chemotherapy in estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2)-positive breast cancers. Evaluation of ColXα1 expression patterns suggests a potential connection with elastin fibers. To investigate the possible interaction between ColXα1 and elastin, we evaluated the expression of ColXα1 in relation to elastin fibers in normal breast tissue, ductal carcinoma in situ, and invasive breast carcinomas at cellular and subcellular levels. Our findings demonstrate that ColXα1 colocalizes with elastin in invasive breast cancer-associated stroma by immunohistochemistry, immunofluorescence, and electron microscopy. In 212 invasive breast carcinomas, this complex was aberrantly and selectively expressed in tumor extracellular matrix in 79% of ER+/HER2-, 80% of ER+/HER2+, 76% of ER-/HER2+, and 58% of triple negative breast cancers. In contrast, ColXα1 was generally absent, while elastin was present perivascularly in normal breast tissue. ColXα1 and elastin were coexpressed in 58% of ductal carcinoma in situ (DCIS) in periductal areas. In mass-forming DCIS with desmoplastic stroma, the complex was intensely expressed in periductal areas as well as within the tumor-associated stroma in all cases. Our data suggest that the breast carcinoma neoplastic process may involve aberrant expression of ColXα1 and elastin in the tumor microenvironment emerging early at the DCIS stage. Enrichment of these complexes in tumor-associated stroma may represent a stromal signature indicative of intrinsic differences between breast cancers. These findings shed light on investigation into the role of aberrant collagen complex expression in tumorigenesis and tumor progression which may be leveraged in therapeutic and theranostic applications.

Topics: Adult; Aged; Biomarkers, Tumor; Breast Neoplasms; Carcinoma, Ductal, Breast; Carcinoma, Intraductal, Noninfiltrating; Collagen Type X; Elastin; Extracellular Matrix; Female; Gene Expression Regulation, Neoplastic; Humans; Middle Aged; Receptors, Estrogen; Tumor Microenvironment

Elastosis is a prominent feature of the desmoplastic reaction in many invasive breast cancers. It is widely held that the elastic tissue is produced by fibroblastic cells of the breast stroma, but several studies have suggested that it derives from breast cancer epithelium. In studies directed to examining the mechanisms regulating desmoplasia in breast cancers, cell lines of human breast cancer derivation have been shown to synthesize immunoreactive tropoelastin in cell culture. Stromal fibroblasts, grown out from breast cancers, produced as much elastin as did nuchal ligament fibroblasts at similar passages. The human breast cancer cell lines, grown under similar conditions, produced elastin in culture at rates equivalent to 1.6-15% of those of the control fibroblastic cells. These included two estrogen receptor positive and one estrogen receptor negative cell types. Northern blot analysis of total RNA showed the presence, under high stringency conditions, of a 3.5-kilobase elastin mRNA band in both the fibroblastic cells and the cancer cell lines. In situ hybridization, with an elastin complementary RNA probe (prepared from a short segment of the translated region of human elastin mRNA), has been carried out on a selection of 21 invasive ductal breast cancers and 9 normal breast samples. It has been found that, while fibroblastic cells of the stroma and of the periductal region are responsible for elastin synthesis in most breast cancers, the malignant epithelium is a source of the elastin in the desmoplastic tissue of a significant proportion of such neoplasms. Vascular endothelium also expresses the elastin gene in some breast cancers. The elastotic elastin may have different cellular origins in different portions of a single ductal breast cancer. The results indicate that elastosis in breast cancers is very likely to be a complex process with multifactorial regulatory mechanisms. Subclassifying cancers according to the cellular source of the desmoplastic elastin, on the basis of in situ hybridization of elastin mRNA, may provide insights into the prognostic significance of elastosis in breast cancers.

Topics: Adult; Aged; Blotting, Northern; Blotting, Western; Breast Neoplasms; Carcinoma, Intraductal, Noninfiltrating; Cell Line; Elastin; Epithelium; Gene Expression; Humans; Middle Aged; Nucleic Acid Hybridization; RNA, Messenger; RNA, Neoplasm; Tropoelastin

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

Topics: Adult; Aged; Amyloid; Breast Neoplasms; Carcinoma, Intraductal, Noninfiltrating; Elastin; Female; Histocytochemistry; Humans; Hyalin; Middle Aged

Topics: Age Factors; Breast; Breast Neoplasms; Carcinoma; Carcinoma, Intraductal, Noninfiltrating; Elastic Tissue; Elastin; Microscopy, Electron; Pancreatic Elastase; Staining and Labeling