Distribution of laminin, a basement membrane glycoprotein in epithelial proliferations. A preliminary study in the breast, the lungs and uterine cervix.

Distribution of laminin, a basement membrane glycoprotein, was studied by an indirect immunofluorescence technique in benign, dysplastic and malignant lesions of breast, lungs and uterine cervix as compared with normal tissues. Laminin was present with a linear and continuous staining in epithelial and vascular basement membranes in normal tissues, benign and dysplastic lesions and in in situ carcinomas of the uterine cervix. By contrast, laminin was absent or very irregularly distributed around malignant infiltrating tumoral clusters. Of particular interest was the linear and disrupted labeling observed in intra-epithelial carcinomas of breast and bronchi. Loss of laminin in these conditions could be related to a potential tumoral invasion.