IMMUNOLOCALIZATION OF INTEGRINS IN THE NORMAL AND NEOPLASTIC COLONIC EPITHELIUM

Cryosections of normal colon (NC), tubular and villous adenomas (TA, V A), and variably differentiated colon adenocarcinomas (CA) were immuno stained with monoclonal antibodies to alpha1-6 and alpha(v), and beta1 -4 integrin subunits; select samples were stained for cytokeratin (Ck) 20 and villin. In NC, alpha2 staining was strongest in crypt cells; a lpha1,3 and alpha(v), and beta1,3 and beta4, and Ck 20 and villin pred ominated in superficial enterocytes. In TA and VA, monolayered glands showed integrin, Ck 20 and villin patterns that differed slightly from both crypt and superficial enterocytes. Complex glands in VA showed d ecreased integrin staining and basal polarization; Ck 20 and villin we re strong only in luminal cells. CA showed overall weaker integrin sta ining than adenomas. Regardless of invasion depth, well formed maligna nt glands mimicked TA; pleomorphic glands mimicked VA with focal basal integrin polarization and solid clusters displayed scanty integrins, uneven Ck 20, and villin in occasional cells. Diverse integrins in cry pt compared with superficial enterocytes reflect changing adhesive req uirements as cells migrate and terminally differentiate. Decreasing ex pression and altered distribution of integrins, Ck 20 and villin noted in TA, VA, and in CA of increasing grade indicate that certain adhesi ve and cytoskeletal features more closely relate to glandular architec ture than to depth of invasion.