The integrin superfamily of adhesion receptors mediates interactions between cells and the extracellular matrix. Our earlier immunohistochemical analysis showed that normal mammary epithelium expressed high levels of the α2β1 collagen/laminin receptor and intermediate levels of the α5β1 fibronectin receptor. In contrast, malignant cells of adenocarcinoma of the breast exhibited marked diminution or loss of the α2β1 and α5β1 integrins. We have now evaluated the level of α2, α5, and β1 integrin subunit messenger (m)RNA by in situ hybridization in adenocarcinoma of the breast. Normal breast ducts and ductules expressed high levels of all three integrin subunit mRNAs. Poorly differentiated lesions expressed low to undetectable levels of α2, α5, and β1 mRNA. Well- and moderately differentiated lesions expressed all three subunits at intermediate levels. Thus, decreased expression of the α2β1 and α5β1 integrins in mammary carcinoma is the result of decreased steady-state integrin subunit mRNA levels due to altered expression of the integrin genes.
|Original language||English (US)|
|Number of pages||10|
|Journal||American Journal of Pathology|
|State||Published - 1993|