Cell surface properties of normal, differentiating, and neoplastic pancreatic acinar cells.

Acinar, centroacinar, and endocrine cells of the adult rat pancreas each exhibit distinctive cell-surface glycoconjugate patterns as detected by binding of a battery of lectin-ferritin conjugates. Acquisition of these unique glycoconjugate patterns appears to be developmentally regulated, as studies on embryonic rat pancreases at days 15, 17, and 19 of gestation indicate. Further, the three cell types appear to arise from a common stem cell(s) with surface glycoconjugate properties similar to those of the adult centroacinar cell. STudies on the cell-surface properties of a rat acinar cell tumor indicate that the neoplastic acinar cells are likely to be arrested at a developmental stage equivalent to acinar cells of the day 19 embryonic pancreas and are characterized by absence of detectable basal lamina. We hypothesize that pancreatic cancers may arise from the equivalent of the undifferentiated embryonic stem cell(s) and that the morphologic features of the tumor depend on the extent of cell differentiation, including expression of cell-surface glycoproteins and extracellular matrix, prior to neoplastic proliferation.