Tenascin expression in elastotic cuffs of invasive ductal carcinoma of the breast

Assessment of elastosis in invasive ductal carcinoma of the breast compared to fibroadenoma among Sudanese patients using conventional histochemical methods

We aimed to identify, using histochemical methods, the degree of elastosis in a malignant breast tumor compared to a benign tumor. Sixty-four tissue blocks were used in this study of which 34 (53.1%) were Invasive ductal carcinoma (IDC) (cases) and 30 (46.8%) were fibroadenomas (controls). Examination of Verhoeff's stained sections revealed different grades of elastosis in 29 (85.2%) cases compared to seven (23.3%) in controls. These findings indicated that elastosis was a prominent feature of IDC (p < 0.000). IDC was associated with more frequent occurrence of different grades of elastosis and should, therefore, be considered a valuable histological finding. Nevertheless, more advanced technology for quantitative measurements of the staining density is recommended to confirm this variation.

Immunohistochemical expression of extracellular matrix components tenascin, fibronectin, collagen type IV and laminin in breast cancer: their prognostic value and role in tumour invasion and progression

The immunohistochemical expression of the extracellular matrix (ECM) components tenascin (TN), fibronectin (FN), collagen type IV (Coll) and laminin (LN), and their possible relationships were studied in a series of 134 operable breast cancer cases. Their expression was also compared with the expression of the proteolytic enzyme cathepsin D (CD), the adhesion molecule CD44 standard form (CD44s) and other known factors to clarify the prognostic value and role of these molecules in tumour progression and metastasis. TN expression in the tumour stroma was positively correlated with tumour grade and size, CD44s expression, tumour and stromal CD expression as well as with FN, laminin and Coll expression in the same areas. TN expression was inverse correlated with ER status. Its expression at the invasion front was only positively correlated with the lymph node status. Survival analysis showed an increased mortality risk associated with high levels of TN expression. In multivariate analysis, among the ECM proteins, only TN expression was independently correlated with patients' survival. FN expression was positively correlated with lymph node involvement, with the proliferation-associated index Ki-67 and stromal CD expression. Survival analysis showed an increased mortality risk associated with a high level of FN expression. Coll expression was positively correlated with the tumour size and LN expression. An inverse relationship of Coll expression with ER and PgR receptor status was also found. LN expression was positively correlated with tumour and stromal CD expression, with the proliferation-associated index Ki-67 and inversely with ER receptor status. The observed alterations in the expression of ECM proteins in breast cancer tissue and their correlations with the proteolytic enzyme CD and the adhesion molecule CD44s, suggest an involvement in cancer progression. In addition, overexpression of stromal TN and FN seems to have negative prognostic value in breast cancer patients.

Tenascin-C expression and distribution in cultured human chondrocytes and chondrosarcoma cells

Tenascin-C (TNC) is an oligomeric glycoprotein of the extracellular matrix with several distinct isoforms variably expressed during embryogenesis, tumorogenesis, angiogenesis and wound healing. In the normal human adult, TNC is found in large concentrations in articular cartilage, suggesting tissue-specific function. The purpose of this study was to determine the specific in vitro TNC splicing patterns of articular chondrocytes and a human chondrosarcoma cell line. Cells were cultured in a three-dimensional bead system and TNC splice variant expression and distribution were examined with the use of Western blotting techniques, semi-quantitative reverse-transcription polymerase chain reaction and immunohistochemistry. At both the transcriptional and post-translational levels, the chondrocytes were found to express significantly higher levels of the smaller 220 kDa isoform (P < 0.01), which was predominantly incorporated into the matrix. The splicing pattern of the malignant cells was characterized by a higher proportion of the larger 320 kDa isoform which was extruded into the media. In vivo studies are necessary to verify the expression of the large TNC isoform in chondrosarcoma and the production and integration of the smaller isoform in normal chondroid matrix. In addition, elucidation of the biologic functions of the two major TNC isoforms may lead to the development of novel diagnostic and therapeutic approaches to chondrosarcoma.