IMMUNOLOCALIZATION OF PS2, A PUTATIVE GROWTH-FACTOR, IN PANCREATIC-CARCINOMA

pS2 is a 60 amino acid secretory polypeptide which belongs to a newly described family of trefoil-shaped growth factors. It is widely distri buted throughout the gastrointestinal tract, particularly adjacent to damaged mucosa, and is also expressed by some epithelial rumours such as breast carcinoma. The aim of this study was to examine the expressi on of pS2 in pancreatic cancer. The presence of pS2 was analysed immun ohistochemically using two antibodies, a polyclonal (pNR-2) and a mono clonal (pS2(TM)) in 42 cases of pancreatic adenocarcinoma and 10 cases of ampullary carcinoma. The findings were compared with chronic pancr eatitis and normal pancreas. No immunostaining was seen in normal panc reas, with the exception of one area of ductular proliferation, and al though 8/10 cases of chronic pancreatitis expressed pS2, it was focal and confined to the occasional duct. In contrast, a significant propor tion of malignant cells in 23/4 2 (55%) of pancreatic adenocarcinoma a nd 8/10 (80%) of ampullary rumours expressed immunoreactive pS2. The f inding of pS2 expression in more than 50% of pancreatic and ampullary carcinomas in contrast to the findings seen in chronic pancreatitis an d normal pancreas suggests that pS2 may play an important role in the growth of these highly malignant tumours.