HUMAN DUCTAL ADENOCARCINOMAS OF THE PANCREAS EXPRESS EXTRACELLULAR-MATRIX PROTEINS

Pancreatic ductal adenocarcinomas are characterised by a dense connect ive tissue reaction. To test the hypothesis that stroma components are synthesised and produced by the tumour cells themselves, eight cell l ines as well as six xenografted rumours from human ductal adenocarcino mas of the pancreas were examined for the expression of extracellular matrix proteins (ECM), using cDNA probes and antibodies to collagen ty pes I, III and IV, vitronectin, fibronectin, undulin and laminin. All tumour cell lines (CAPAN-1, CAPAN-2, AsPC-1, BxPC-3, PANC-1, PaCa-2, P aCa-3, PaCa-44) and xenografted human pancreatic rumours expressed at least one of the examined ECM at the RNA (collagen type IV > laminin = fibronectin = vitronectin > collagen type III > undulin > collagen ty pe I) or protein level (collagen type IV = collagen type III > vitrone ctin > laminin > collagen type I = fibronectin > undulin). In nude mou se rumours expression of laminin and collagen I was most pronounced in well-differentiated carcinomas. In a few rumours, collagen type III, vitronectin and undulin were expressed on the luminal side of the neop lastic glands, suggesting loss of normal polar differentiation. Incuba tion with fetal calf serum modulated ECM RNA levels to a varying exten t in all but one cell line (AsPC-1). The results suggest that human pa ncreatic ductal adenocarcinomas cells are capable of synthesising and producing extracellular matrix proteins in vitro and in vivo, but that the extent and pattern of ECM expression differs between the various rumours and conditions tested.