EXPRESSION OF HEMIDESMOSOMAL AND EXTRACELLULAR-MATRIX PROTEINS BY NORMAL AND MALIGNANT HUMAN PROSTATE TISSUE

The progression of prostate carcinoma may be influenced by the biochem ical nature of the basal lamina surrounding the primary carcinoma cell s. As a first step toward understanding this process, the composition and structure of the basal lamina in normal prostate, prostatic intrae pithelial neoplasia, and human carcinoma were determined In addition, a comparison was made between the attachments of the normal basal cell to its underlying basal lamina and those made by primary prostate car cinoma. The normal basal cells form both focal adhesions and hemidesmo somal-like structures as observed by transmission electron microscopy The normal basal cells exhibited a polarized distribution of hemidesmo somal associated proteins including BP180, BP230, HD1, plectin, lamini n-gamma 2 (B2t), collagen VII, and the corresponding integrin laminin receptors alpha 6 beta 1 and alpha 6 beta 4. The expression and distri bution pattern of these proteins were retained in the prostate intraep ithelial neoplasia lesions. In contrast, the carcinoma cells uniformly lacked hemidesmosomal structures, the integrin alpha 6 beta 4, BP180, laminin-gamma 2 (B2t), and collagen VII but did express BP230 (30%), plectin, HD1 (15%), and the integrin laminin receptors alpha 3 beta 1 and alpha 6 beta 1. These results suggest that, although a detectable basal lamina structure is present in carcinoma, its composition and ce llular attachments are abnormal. The loss of critical cellular attachm ents may play a role in influencing the progression potential of prost ate carcinoma.