Elastosis in breast carcinoma: II. Association of protease inhibitors with immature elastic fibres

Effect of smoking on skin elastic fibres: morphometric and immunohistochemical analysis

BACKGROUND

It has been established during recent years that smoking is an independent risk factor for the development of premature facial wrinkling. The underlying mechanism is not well known, but elastic fibres of the dermis seem to be the major target of smoke components.

OBJECTIVES

To determine quantitative and qualitative changes of the dermal elastic tissue of non-sun-exposed skin induced by smoking, as well as the possible mechanisms responsible for them.

METHODS

Sixty-nine patients were recruited (20 nonsmokers, 19 former smokers and 30 smokers). Using static morphometry and immunohistochemistry and lectin staining we analysed elastic fibres of the dermis and their major components, elastin and microfibrillar component.

RESULTS

Significantly higher values for the number of elastic fibres mm(-2) and the percentage of the area filled by them in the reticular dermis were found in smokers. Cumulative tobacco dose showed statistically significant correlations with both morphological parameters (Spearman's rank correlation coefficient). Immunohistochemistry demonstrated that the two main components of elastic fibres were altered in smokers. Plasma protease inhibitors and lectin staining were negative in all the samples.

CONCLUSIONS

Smoking is an independent risk factor for the increase of elastic fibres in the reticular dermis of nonexposed skin, and it acts on their two main structural components, elastin and microfibrillar component. This increase in the area of elastic fibres in smokers is not due to newly synthesized elastic material, but to their degradation, as occurs in solar elastosis and which acts in an additive manner.

Cyclopentenosine, major trifunctional crosslinking amino acid isolated from acid hydrolysate of elastin

A trifunctional crosslinking amino acid named cyclopentenosine (CP) was isolated from the hydrolysate of bovine nuchal ligament elastin. CP and its derivatives were identified by spectroscopic methods. CP was found to consist of a 2-cyclopenten-1-one structure and its imine-enamine tautomers with enantiomers in H(2)O. A model reaction for the formation of the CP crosslink using model compounds for allysine (propanal) and lysine (n-butylamine) demonstrated that CP is composed of 2-cyclopenten-1-one and alpha, beta, gamma, delta-unsaturated aldehyde derived from three allysine residues. An ion-paired high-performance liquid chromatographic method for the determination of CP was developed. Among various bovine tissues the nuchal ligament had the highest concentration of CP. The age-related changes in the concentration of CP were examined in the aorta from rat (short-lived species) and bovine (long-lived species). The CP content was very low in the newborn rat but increased markedly with growth. After maturity, the CP content remained nearly the same or slightly decreased. In bovine aorta, the CP content scarcely changed from 7 months to 16 years.

Relation of elastosis to biochemical and immunohistochemical steroid receptor findings, Ki-67 and epidermal growth factor receptor (EGFR) immunostaining in invasive ductal breast cancer

We studied 1073 cases of invasive ductal breast cancer, NOS for their elastic content (DEL, ductal+periductal elastosis; TEL, tumour elastosis) and compared the findings with the results of biochemical and immunohistochemical steroid hormone receptor examination. Tumours of patients up to 50 years of age and older were examined separately. In a number of tumours elastosis was also examined in relation to Ki-67 and epidermal growth factor receptor (EGFR) immunostaining. Sensitivity and specificity of DEL and TEL for predicting the receptor, Ki-67 and EGFR findings were estimated. Sensitivity of DEL and TEL for oestrogen and progesterone receptors is dependent on the degree of tumour differentiation and the degree of elastosis, increasing from DEL 1 degree and TEL 1 degree to DEL 3 degrees and TEL 3 degrees. It was more evident in grade 1 (G1) and G2 than in G3 carcinomas. Elastosis is a useful predictor of positive receptor findings particularly in G1 and G2 tumours with moderate and high-grade elastosis. It is a similarly useful predictor of negative receptor values in G3 carcinomas. The predictive value of DEL and TEL for the results of Ki-67 and EGFR immunostaining gradually decreases with increasing elastosis, consistent with the assumption that Ki-67 and EGFR identify the degree of tumour proliferation and invasion, while elastosis correlates with the degree of differentiation of breast cancer. Elastosis is a poor predictor of Ki-67 and EGFR findings in any individual breast cancer. Moderate and high-grade elastosis points to positive steroid hormone receptor assays in G1 and G2 carcinomas. In contrast, the lack of elastosis in G3 carcinomas may indicate a negative receptor assay. Both findings have a high degree of reliability.

Role of elastic fiber degradation in emphysema-like lesions of pulmonary lymphangiomyomatosis

To study the pulmonary structural remodeling in pulmonary lymphangiomyomatosis, electron microscopy and light and electron microscopic immunohistochemical observations for elastin and alpha 1-antitrypsin were performed on five open lung biopsy samples. Lung specimens showed emphysema-like changes in areas of abnormally accumulated smooth muscle cells. In the alveolar walls having accumulated smooth muscle cells, elastic fibers were decreased in number, disrupted, granular, and occasionally accumulated. Ultrastructurally, elastic fibers in areas of smooth muscle cell accumulation showed poorly outlined amorphous components and a few microfibrils, and occasionally showed electron-dense granular deposits in and around the amorphous components. Spiraling collagen fibrils were frequently found associated with these abnormal elastic fibers. Immunohistochemistry for elastin showed even staining of amorphous components of elastic fibers in the areas of smooth muscle cell accumulation. alpha 1-Antitrypsin was also detected evenly in amorphous components of elastic fibers in the areas of smooth muscle cell accumulation. It is proposed that the emphysema-like lesions of lymphangiomyomatosis are mediated by the degradation of elastic fibers, and these degraded elastic fibers are related to an imbalance of the elastase/alpha 1-antitrypsin system similar to the probable pathogenesis of emphysema.

Stromal changes in early invasive breast carcinoma. An immunohistochemical, histoenzymological and ultrastructural study

The purpose of this work was to detect in periductal connective tissue of breast carcinoma in situ changes induced by intraductal tumor cells before any dehiscence in basement membrane. Histological, electron microscopic, immunohistochemical and histoenzymological methods were used in 3 carcinomas in situ, 4 microinvasive carcinomas and 13 control invasive carcinomas. We could demonstrate a high functional activity of fibroblasts with secretion of mucopolysaccharides and type III collagen around intraductal carcinomas. These changes occurred simultaneously to those of the basement membrane which was either thinning or thickening. Any dehiscence in basement membrane secondarily induced in this periductal stroma the usual changes seen in invasive stroma, peculiarly numerous vascular pedicles, myofibroblasts, elastic material. These periductal stromal changes are interpreted according to recent concepts about the possible influence of tumor cells upon their environment: stimulation of mitotic and metabolic activity of fibroblasts: stimulation of angiogenesis by means of an angiogenic factor.

Abnormal elastic fibers in elastosis of breast carcinoma. Ultrastructural and immunohistochemical studies

Elastosis in benign and malignant breast lesions was studied by light microscopic immunohistochemistry for elastin and by electron microscopy. Upon immunohistochemical examination for elastin, elastosis, particularly in scirrhous-type ductal carcinoma, showed two characteristic staining patterns: fibrously and intensely stained elastic fibers and evenly stained elastic masses. Elastic fibers showing increased fibrous staining occurred mainly in the stromal areas, and were considered to be newly formed because they consisted of tannic acid-positive amorphous components and abundant microfibrils. Evenly stained elastic masses were observed mainly in the periductal areas and showed less intense stainability. These masses consisted of numerous fine amorphous components with plentiful microfibrils. In some regions within these masses, there were condensed accumulations of irregularly arranged small amorphous components associated with only a few microfibrils. These amorphous components had an ill-defined outline and were occasionally associated with spiralling collagen fibrils and cell debris. On the basis of these findings, the periductal evenly stained elastic masses were thought to be formed by excessive production of elastic fibers and degradation of pre-existing and newly formed elastic fibers.