DIFFERENTIAL EXPRESSION OF HEAT-SHOCK PROTEINS IN PANCREATIC-CARCINOMA

in the present study we sought to determine by Northern blot analysis and MRNA in situ hybridization whether gene expression of heat shock p roteins (HSPs) (HSP 89alpha, HSP 89beta, HSP 70, and ubiquitin) is alt ered in pancreatic carcinoma, compared to control tissues (normal panc reas and chronic pancreatitis tissue). HSP 89alpha was selectively ove rexpressed in pancreatic carcinoma, and tumor cells were shown to cont ain the largest amount of HSP 89alpha mRNA. Steady state levels of HSP 70 mRNA were increased in pancreatic carcinoma (tumor and connective tissue cells) and in chronic pancreatitis (connective tissue cells and residues of exocrine acinar cells). HSP 89beta and ubiquitin B were c onstitutively expressed at high levels in pancreatic tissue from all t hree groups; HSP 89beta mRNA was found in cells of parenchymal and str omal origin. A strong correlation was found between the expression of HSP 70 and the expression of transforming growth factor beta1. The fin ding that HSPs are differentially expressed in pancreatic cancer, comp ared to normal pancreas and chronic pancreatitis tissue, and the cance r specifity of HSP 89alpha suggest that HSPs play a specific role in t he pathogenesis of pancreatic cancer, e.g., by participating in regula tory processes or in tumor immunity, as proposed previously.